zbornikradova - Geodetski fakultet Sveučilišta u Zagrebu
Transcription
zbornikradova - Geodetski fakultet Sveučilišta u Zagrebu
HRVATSKI GEODETSKI INSTITUT ZBORNIK RADOVA HRVATSKOG GEODETSKOG INSTITUTA 2001. - 2005. Zagreb, prosinac 2005. Nakladnik: Mjesto izdavanja: Godina izdavanja: Naslov publikacije: Broj stranica: Za izdavatelja: Urednik: Tehnički urednici: Tisak: Naklada: HRVATSKI GEODETSKI INSTITUT 10144 Zagreb, pp 19, Savska cesta 41/XVI Telefon +385-1-6312400, telefax +385-1-6312410 E-pošta [email protected], Internet www.hgi.htnet.hr Zagreb 2005. Zbornik radova Hrvatskog geodetskog instituta 2001.-2005. 127 prof. dr. sc. Nevio Rožić prof. dr. sc. Nevio Rožić mr. sc. Ilija Grgić Slavko Lemajić, dipl. ing. geod. Sonja Marketić Pašić, dipl. iur. Hrvatski geodetski institut 80 primjeraka CIP - Katalogizacija u publikaciji Nacionalna i sveučilišna knjižnica - Zagreb UDK 528(497.5)(082) ZBORNIK radova Hrvatskog geodetskog instituta : 2001. - 2005. / <urednik Nevio Rožić>. - Zagreb : Hrvatski geodetski institut, 2006. Tekstovi na hrv. i engl. jeziku. - Kazalo. ISBN 953-95318-0-2 1. Hrvatski geodetski institut (Zagreb) I. Geodezija -- Hrvatska -- Zbornik 460113063 ISBN 953-95318-0-2 UVOD Dokumentiranje i objavljivanje rezultata obavljenih stručnih, znanstvenih i razvojnih zadaća jedan je od temeljnih uvjeta sustavnog obavljanja poslova, stavljanja na raspolaganje postignutih rezultata i saznanja stručnoj i znanstvenoj javnosti, trajnog bilježenja rezultata rada kao odraza trenutka vremena i prioriteta aktivnosti: pojedinaca, timova i institucija (ustanova) u cjelini. Iz perspektive mladih, odnosno novih ustanova, posebice ustanova s predznakom visokostručne, znanstvene i razvojne aktivnosti, pisano dokumentiranje i publiciranje obavljenih radova, kako na internoj, tako i na eksternoj razini, ima posebice velik značaj. Naime, publiciranje radova pridonosi afirmirmaciji ustanove, izgradnji i stjecanju stručne i znanstvene vjerodostojnosti te promoviranju djelatnosti, specijaliziranosti i djelokruga odgovornosti. Tijekom prvog četverogodišnjeg ciklusa rada Hrvatskog geodetskog instituta, u razdoblju 2001.-2005. godine, dokumentiranju i publiciranju rezultata radova posvećena je primjerena pozornost. Pri tomu, posebno mjesto svakako imaju oni radovi zaposlenika Instituta, timova i Instituta u cjelini koji su predstavljeni javnosti na međunarodnim i domaćim skupovima (kongresi, simpoziji) te koji su ujedno otisnuti u zbornicima radova tih skupova ili odgovararjućim znanstvenim i znanstveno-stručnim časopisima. Pomenute radove, iako su tematski i sadržajno različiti, povezuju dvije razvidne činjenice. Prije svega činjenica da su sadržajno i kvalitetom zadovoljili procedure recenziranja, prezentiranja i objavljivanja na relevantnim instancama, a u relativno složenim uvjetima osnivanja i rada Instituta u njegovom prvom četverogodišnjem razdoblju rada, kada je primarna energija i fokus institutskih stručnjaka, uz prilično ograničene resurse, primarno bila usmjerena prema ustroju, razradi i definiranju stručnih i razvojnih procesa Instituta. Druga je činjenica definirana izvrsnošću radova, jer su uz pridržavanje svih načela izrade i razrade znanstvenog i znanstveno-stručnog sadržaja, korektno izrazili, uobličili i javnosti predočili rezultate obavljenih radova. U ovom je Zborniku sakupljen i objedinjen pretežan dio relevantnih radova vezanih uz Institut, koji su objavljeni u razdoblju 2001.-2005. godine. Radovi su uvršteni u Zbornik u njihovom izvornom sadržaju i jeziku publiciranja, bez dopunske recenzije, uz minimalno (ipak neophodno) tehničko prilagođenje formatu tiska i estetsko uređenje teksta. Za svaki je rad precizno i faktografski navedena publikacija u kojoj je izvorno objavljen, odnosno znanstveni ili znanstveno-stručni skup na kojem je predstavljen. Redosljed radova u Zborniku je određen sukladno vremenskom slijedu publiciranja. Potrebno je naglasiti da pokretanje edicije Zbornika radova Hrvatskog geodetskog instituta ima važnu svrhovitost. Ima svrhovitost objedinjavanja i očuvanja rezultata rada stručnjaka Instituta, stvaranja trajne uporabne vrijednosti i referentnosti objavljenog sadržaja, odnosno ima funkciju promicanja i afirmiranja Instituta u cjelini. Čini se uputnim, što će svakako ovisiti o intenzitetu aktivnosti Instituta u narednom razdoblju, priređivati Zbornik radova Hrvatskog geodetskog instituta bar u četveregodišnjem vremenskom ciklusu. Također, kao primjeren kriterij uvrštenja radova u Zbornik i nadalje je uputno zadržati kriterij prethodne publiciranosti radova u meritornim znanstvenim ili znanstveno-stručnim časopisima, odnosno prezentiranosti na relevantnim međunarodnim ili domaćim skupovima. Zagreb, prosinac 2005. Ravnatelj HGI Prof. dr. sc. Nevio Rožić INTRODUCTION Documenting and publishing of the professional, scientific and development tasks results done is one of the basic conditions for systematic dealing with jobs, placing the achieved results and findings at disposal to professional and scientific public, for permanent recording of the working results being the reflection of the moment and the priority in the activities of individuals, teams and institutions as a whole. From the perspective of the young, i.e. new institutions, especially those characterized by highly professional, scientific and developmental activities, the written documenting and publishing of the works done at internal as well as at the external level has got a very large significance. Namely, the publishing of works makes great contributions in promoting the institution, building and acquiring professional and scientific credibility and promoting the activity, specialisation and the scope of responsibility. During the first four-year working cycle of the Croatian Geodetic Institute in the period between 2001 and 2005, special attention has been paid to documenting and publishing of the works. In this respect, special attention has been given to those works of the employees in the Institutes, the teams and the whole Institute that were presented to the public at international gatherings abroad and at home (congresses, symposia), and that were printed in the proceedings of these gatherings or in adequate scientific, and scientific-professional magazines. The above-mentioned works, although thematically and contextually different, are connected by two obvious facts. First of all, it is the fact that they have met the requests of review procedures, of the presentation and publishing at relevant levels, and having in mind relatively complex conditions in which the Institute was being founded and was working in its first four-year working cycle, when the primary energy and attention of the Institute employees was first of all focused toward constitution, elaboration and defining of professional and developmental process of the Institute with pretty limited resources. Almost all works relevant to the Institute and published in the period between 2001-2005 are gathered in these Proceedings. The works are introduced into the Proceedings in their original form and in the original language of publishing, without any additional reviewing, with minimal (really indispensable) technical adjustment to the printing format and aesthetical text editing. There are precise and correct data given for each work about the publication in which it had been originally published, i.e. the scientific, or scientific and professional gathering at which it had been presented. The order of the appearance of the works in the Proceedings has been determined in accordance with the time they were published respectively. It should be pointed out that the edition of the Proceedings of the Croatian Geodetic Institute has been initiated with a very important purpose. The purpose is to unite and keep the results the experts from the Institute have achieved, to create permanent application value and reference of the published contents, i.e. to promote and affirm the Institute on the whole. It seems advisable, and it will of course depend on the intensity of the Institute's activity in the forthcoming period, to work on the preparation of the Proceedings at least within the four-year cycle. It is also recommendable to take the previous publishing of the works in competent scientific, or scientific and professional magazines, i.e. their presentation at relevant international gatherings abroad or at home as the criteria for their introduction into the Proceedings. Zagreb, December 2005 Director of CGI Prof. Dr. Sc. Nevio Rožić SADRŽAJ Nevio Rožić Hrvatski geodetski institut …….7 Nevio Rožić Croatian Geodetic Institute …….9 Nevio Rožić Accuracy of geometric levelling networks at the territory of Croatia …...11 Željko Hećimović, Danko Markovinović Stabilnost mjernog sustava Scintrex HGI-2 gravimetra …...17 Nevio Rožić Točnost visinske osnove geometrijskog nivelmana na teritoriju Republike Hrvatske …...25 Željko Hećimović, Nevio Rožić, Tomislav Bašić, Danko Markovinović Status of the Croatian First Order Gravity Network …...33 Nevio Rožić Strategy and System of Quality Control of the Official Geographic Data produced by Private Companies in Croatia …...41 Željko Bačić, Nevio Rožić Cambridge Conference 2003 "National Mapping – Shaping the Future" …...47 Nevio Rožić, Slavko Lemajić, Mladen Rapaić Croatian-Norwegian GeoInformation Project …...51 Slavko Lemajić, Nevio Rožić, Mladen Rapaić Improvement of Quality Control System in Croatia …...57 Stanislav Frangeš, Mladen Rapaić Creating the toponymic database of the Republic of Croatia - Project Toponimis, as sub-project of STOKIS …...65 Ilija Grgić Specifičnosti geodetske osnove u tunelogradnji …...71 Nevio Rožić Changes of benchmark heights being the consequence of introducing the new Croatian height system …...73 Željko Hećimović, Bojan Barišić, Ilija Grgić Eeuropean vertical reference network (EUVN) considering Champ and Grace gravity models …...81 Mladen Rapaić, Stipica Pavičić, Slavko Lemajić Topographic data production as basis for NSDI - Croatian example …...91 Ilija Grgić, Slavko Lemajić, Bojan Barišić Visinska kontrola geodetskih i kartografskih proizvoda u procesu topografske i katastarske izmjere ….101 Slavko Lemajić, Višnja Miloš, Ilija Grgić Kontrola kvalitete DOF-a u procesu katastarske izmjere ….107 Bojan Barišić, I. Vilibić, Ilija Grgić Metodologija određivanja crte srednjih viših visokih voda ….113 Ilija Grgić, Bojan Barišić, Mihajla Liker Status of the EUVN and EUVN_DA projects in Croatia ….119 Višnja Miloš Digitalni ortofoto u Republici Hrvatskoj i u svijetu: norme i stanje u praksi ….125 HRVATSKI GEODETSKI INSTITUT* Nevio Rožić Od 1. ožujka 2000. godine u Republici Hrvatskoj se primjenjuje Zakon o državnoj izmjeri i katastru nekretnina (Narodne novine 128/99), koji je donio Zastupnički dom Hrvatskog državnog sabora na sjednici od 5. studenoga 1999. godine. Taj Zakon donosi brojne i suštinski važne odredbe koje uređuju geodetsku djelatnost u Republici Hrvatskoj, a obuhvaćaju reguliranje kompleksnih područja geodetskih poslova od državnog interesa, kao što su: državna izmjera, katastar nekretnina, registar prostornih jedinica, katastar vodova, geodetski radovi za posebne potrebe, nadležnosti i obavljanje poslova državne izmjere i katastra nekretnina, te ustrojstvo Državne geodetske uprave. Jedna je od važnih odredbi i novina koje donosi ovaj Zakon osnivanje nove ustanove za trajno obavljanje geodetske djelatnosti od interesa za Republiku Hrvatsku, pod nazivom Hrvatski geodetski institut ili skraćeno HGI. U tom je smislu Zakon osnivački akt Instituta i u njemu su u poglavlju IV. točka 3, sukladno Zakonu o ustanovama (Narodne novine 76/93), jasno precizirani elementi potrebni za njegovo osnivanje. Tako je učinjen prvi i iznimno važan korak koji će u idućem razdoblju omogućiti ustrojavanje Instituta i početak rada. Treba naglasiti i istaknuti veliku zaslugu svih sudionika koji su u postupku predlaganja i donošenja Zakona omogućili osnivanje Instituta. Naime, konačno je uspješno realizirana ideja koja je u geodetskoj javnosti Republike Hrvatske u različitim oblicima prisutna četrdesetak godina. Gotovo da i nije potrebno podrobnije obrazlagati genezu, opravdane potrebe i razloge osnivanja Instituta. Oni su i više nego razvidni s obzirom na stanje geodetskog naslijeđa Republike Hrvatske iz prethodnog razdoblja, pojave i primjene suvremenih geodetskih i računalnih tehnologija i koncepcija obavljanja geodetskih radova, preustroja cjelokupne geodetske djelatnosti na načelima tržišnih odnosa i poduzetništva, preustroja ovlasti i tijela državne uprave nadležnih za obavljanje geodetskih poslova, novih nastojanja i nove uloge geodezije u suvremeno orijentiranoj državi i društvu, nove pravne, zakonske i pravilničke regulative i mnogo toga drugoga. U tom smislu Institut je krupna promjena u organizaciji, ovlastima i obavljanju geodetske djelatnosti na državnoj razini i od državnog interesa. Institut se pojavljuje kao novi geodetski subjekt i važna spona koja bi trebala u području vođenja, organiziranja i obavljanja geodetskih radova na nov i drugačiji način povezati postojeće geodetske potencijale države. Prije svega geodetsku operativu, koja se sastoji od niza kvalitetnih i uglednih geodetskih tvrtki ovlaštenih za obavljanje geodetske djelatnosti, Državnu geodetsku upravu Republike Hrvatske i Geodetski fakultet Sveučilišta u Zagrebu. Nije na odmet podsjetiti i na prvu konkretnu inicijativu za osnivanje takve ustanove u Republici Hrvatskoj. Naime, u razdoblju nakon II. svjetskog rata, a posebno nakon osnivanja samostalnoga Geodetskog fakulteta 1962. godine pojavila se i jasno iskazala potreba osnivanja Geodetskog instituta. Ona je bila na Fakultetu potaknuta potrebom izvođenja organiziranog i sustavnog znanstvenoistraživačkog rada u suradnji s geodetskom praksom i potrebom rješavanja niza visokostručnih geodetskih zadaća koje su se nametnule pred geodetsku djelatnost onoga doba. Inicijativa za osnivanje Geodetskog instituta je na Fakultetu i formalizirana. Poprimila je konkretan oblik i ugrađena je u opće akte Fakulteta iz 1964. i 1966. godine. Iako se organizacijski oblik tadašnjeg instituta razlikovao od današnjeg, zanimljivo je iz ove perspektive podsjetiti na neke pojedinosti. Statutom Geodetskog fakulteta iz 1964. godine donesena je odluka o osnivanju Geodetskog instituta Geodetskog fakulteta (čl. 10. Statuta) sa sljedećim temeljnim zadaćama: organiziranje i obavljanje znanstvenog rada te usavršavanje metoda rada u svim područjima geodezije, ispitivanje i analiziranje geodetskih radova s obzirom na točnost, primijenjene metode i ekonomičnost, davanje znanstvene podloge i usavršavanje geodetskih tehnoloških postupaka, suradnja s privrednim i drugim organizacijama, odnosno znanstvenim ustanovama u zemlji i inozemstvu, objavljivanje rezultata znanstvenog i stručnog rada, usavršavanje i izobrazba znanstvenog i stručnog podmlatka i dr. Sukladno odredbama ondašnjeg Zakona o organizaciji naučnog rada, Geodetski je institut trebao djelovati kao znanstvena ustanova, a upravljanje institutom trebalo je biti u ovlasti Savjeta Geodetskog fakulteta i direktora kojeg postavlja Savjet. U tom su razdoblju za osnivanje Geodetskog instituta postojali kadrovski uvjeti, kao i oprema za početak rada, dok su nedostajali prostor i financijska sredstva. Iako je osnivanje instituta podržavala stručna praksa, do osnivanja na žalost nije došlo, bez obzira na visoku razinu pripremljenosti. Konačno, početkom sedamdesetih godina, tj. 1973. godine ideja osnivanja instituta je napuštena i nadomještena novim unutarnjim preustrojem Fakulteta utemeljenim na osnivanju Zavoda. * Objavljeno u Geodetskom listu 2000. godine (Rožić, N.: Hrvatski geodetski institut. Geodetski list, 2000, 4, 293-294). -7- Nakon ovoga kratkog podsjećanja potrebno je iznijeti temeljne i načelne odrednice na kojima počiva osnivanje Instituta danas. Naime, sukladno odredbama Zakona, Hrvatski geodetski institut je javna ustanova sa sjedištem u Zagrebu koja će trajno obavljati poslove državne izmjere i katastra nekretnina koji su od interesa za Republiku Hrvatsku. Osnivač Instituta je Republika Hrvatska, a njezina prava kao osnivača ostvarivat će Vlada Republike Hrvatske. Institut je neprofitabilna ustanova s javnošću rada, koja neće obavljati svoju djelatnost radi stjecanja dobiti. Financiranje i sredstva za početak rada i daljnji rad osigurana su državnim proračunom Republike Hrvatske. Dio potrebne geodetske i računalne opreme Institutu će staviti na raspolaganje Državna geodetska uprava. Institut treba djelovati sukladno Zakonu, Zakonu o ustanovama, vlastitim općim aktima i svim drugim zakonima i propisima koji uređuju njegovu djelatnost. Rad Instituta nadzirat će Državna geodetska uprava, a djelatnost će biti planirana i realizirana sukladno godišnjim programima rada. Ti programi će biti usklađeni s višegodišnjim programima rada predloženima od Državne geodetske uprave i odobrenima od Hrvatskoga sabora i Vlade Republike Hrvatske. Temeljna su tijela Instituta, sukladno Zakonu i Zakonu o ustanovama, Upravno vijeće s 10 članova i ravnatelj, koje imenuje i razrješava Vlada Republike Hrvatske. U Institutu bi trebalo raditi dvadeset djelatnika, a od toga broja petnaestak visoko kvalificiranih geodetskih stručnjaka specijaliziranih u pojedinim užim područjima geodezije. Djelatnost je Instituta u najširem smislu definirana poslovima državne izmjere i katastra nekretnina. Međutim, u užem smislu, vrlo je precizno utvrđena čl. 44. Zakona i obuhvaća: vođenje osnovnih geodetskih radova, ustrojavanje topografskih, kartografskih i katastarskih baza, vođenje topografske izmjere, ustrojavanje i evidenciju zemljopisnih imena, vođenje izmjere i označavanja državne granice, vođenje razvojno-istraživačkih projekata, rad na standardizaciji i normiranju geodetskih radova i postupaka. Uz obavljanje visokostručnih geodetskih poslova Institut će posebnu pozornost posvetiti razvojno-istraživačkoj i znanstvenoj problematici, koja je povezana s unapređenjem stručnog rada, uvođenjem suvremene geodetske i računalne tehnologije te suvremenih standarada i postupaka obavljanja geodetskih radova. U tijeku su aktivnosti povezane s ustrojem Instituta sukladno zakonskim propisima. Prvi je korak u tom smislu imenovanje privremenog ravnatelja Instituta odlukom Vlade Republike Hrvatske. U tijeku je predlaganje i imenovanje članova Upravnog vijeća, izradba prijedloga Statuta Instituta i upis u sudski registar ustanova. Navedene bi aktivnosti trebale biti obavljene u predstojećem razdoblju tako da će kao pravni subjekt Institut početi djelovati i prije isteka ove kalendarske godine. Naravno, ustroj Instituta i početak njegova operativnog rada povezan je i s nizom neriješenih zadaća, kao što su: nalaženje prostora za rad, opremanje suvremenom geodetskom i računalnom opremom, definiranje unutarnjeg ustrojstva sukladno Zakonom utvrđenoj djelatnosti, donošenje potrebnih općih akata, zapošljavanje visokokvalificiranih geodetskih stručnjaka i dr. Na kraju ovoga sažetog i načelnog prikaza o Hrvatskom geodetskom institutu važno je naglasiti da će pri svom ustroju i preuzimanju Zakonom utvrđenih ovlasti svakako trebati veliku potporu svih geodetskih subjekata Republike Hrvatske. Također, u obavljanju svoje djelatnosti krajnje će stručno, odgovorno, konstruktivno i motivirajuće surađivati sa svim domaćim i inozemnim geodetskim ustanovama, tvrtkama, organizacijama, tijelima i udrugama, prinoseći unapređenju, afirmaciji i napretku hrvatske geodezije. -8- CROATIAN GEODETIC INSTITUTE* Nevio Rožić 1. INTRODUCTION After acquiring the independence and sovereignty at the beginning of the 90-ties there were pretty significant and extensive activities initiated in the Republic of Croatia in the field of geodetic and surveying works at the state level. The activities included reorganisation of state bodies and institutions competent for carrying out geodetic and surveying activity of state interest, creating new law and ordinance basis, evaluating and using the inherited geodetic basis of the former state (fundamental state networks, geodetic datums, cartographic and geodetic documentation etc.) and also carrying out new geodetic works at the state level. One of very important activities in terms of modernising geodetic and surveying activity and its organisation in accordance with the experiences and practice of other developed European countries is the foundation of a separate and specialised institution intended for performing scientific and highly professional geodetic activity. This new institution is Croatian Geodetic Institute (CGI). In the Republic of Croatia there had never been such an institution. During the long period of time, from the end of II. World War till the moment of Croatia becoming independent, the realization of professional geodetic and surveying jobs had been always under the competence of Military and Geographic Institute of former Yugoslavia. The foundation of CGI as institution specialised for performing geodetic activity that is of interest to the Republic of Croatia is defined by the Law of State Survey and Real Estate cadastre that was passed by the House of Representatives of the Croatian State Parliament on 5th November 1999 and has been applied since 1st March 2000. As this Law became operative, concrete activities were initiated in connection with the formation and establishment of CGI and have been continuously performed ever since. The bearer of these activities is the State Geodetic Administration (SGA) of the Republic of Croatia. For the first time in the Republic of Croatia administrative and normative jobs in the field of geodesy will be separated from professional jobs. CGI will do the professional jobs and SGA will take care of the administrative and normative jobs at the state level. 2. FOUNDATION AND FORMATION OF CGI In accordance with the Law of State Survey and Real Estate Cadastre, CGI is formed as specialised institution for carrying out scientific and highly professional geodetic works being of interest for the Republic of Croatia, but without the rights to be profitable. The residence of CGI is in Zagreb, the founder is the Government of the Republic of Croatia, and SGA is the bearer of CGI foundation activities. SGA is also legally entitled to supervise its work. The work of CGI is regulated by the Law of State Survey and Real Estate Cadastre, by the Law of Institutions and other positive laws and regulations of the Republic of Croatia. Within its activity CGI is to perform the following jobs: - conduct fundamental geodetic works - constitute topographic, cartographic and land registry databases - conduct topographic survey - constitute and keep geographic names register - conduct survey and marking of state border - conduct development and research projects - standardisation of geodetic works and procedures. CGI will be obligated to perform geodetic works and activity in accordance with the annual working programs harmonised with the working programs of SGA, and to submit reports to the Government of the Republic of Croatia about performed works. Manager of CGI and Managing Board consisting of 10 members run the CGI. They are appointed by the Government of the Republic of Croatia. * Predstavljeno na EUREF2001 simpoziju (Symposium of the IAG Subcommission for Europe – EUREF) održanom u Dubrovniku 16.-18.5.2001. godine. Objavljeno u zborniku radova Simpozija (Rožić, N.: Croatian Geodetic Institute. Mitteilungen des Bundesamtes für Kartographie und Geodäsie, Band 23, EUREF Publication No. 10, Frankfurt am Main, 2002, 211-212). -9- At this moment it is possible to employ 20 people in CGI in accordance with financial possibilities determined by the budget of the Republic of Croatia. They have to be highly qualified experts in the field of geodesy and informatics. Special attention will be paid to additional education and specialisation of these employees, especially in the field of applying recent geodetic technologies of gathering, processing and analysing geodetic data. At this moment there is a procedure going on connected with preparation of adequate regulative and other normative acts of the CGI that should be passed so that the CGI could start functioning normally during the year 2001 in accordance with the law and regulations of the Republic of Croatia. 3. CGI INTERNAL CONSTITUTION AND NEAR FUTURE ACTIVITIES Internal constitution of the CGI is based on the planned type and volume of geodetic works that it should perform. The constitution of four departments is planned: - Department for mutual jobs - Department for fundamental geodetic works - Department for topographic survey and supervising - Department for geoinformational systems and databases. Very important phase in the foundation of CGI and in providing the conditions for it to start operating will be the employment of experts, getting premises for its work, gathering geodetic equipment, more precise defining of its internal constitution and initiation of direct work. The need for the CGI to start working as soon as possible is intensified by very extensive and demanding program of geodetic works at the state level that has been made by the SGA. The implementation of this program, the "Program of state survey and real estate cadastre for the period from 2001 – 2005", will depend also on the activity and efficiency of the work done by the CGI. There is also a need for information about the situation and experiences referring to the work, organisation and constitution of similar institutions in other developed European countries. 4. CONCLUSION In accordance with the intention to constitute CGI as modern and efficient institution that will work successfully on solving the problems in geodetic activity and perform works of interest to the Republic of Croatia it can be concluded that all types of assistance from similar European institutions are welcome having in mind objective circumstances that the geodetic activity and the Republic of Croatia as a whole have found themselves in at the moment. REFERENCES Official Newspaper: The law of State Survey and Real Estate Cadastre, No. 128, Zagreb, 1999. - 10 - ACCURACY OF GEOMETRIC LEVELLING NETWORKS AT THE TERRITORY OF CROATIA* Nevio Rožić ABSTRACT In the period between 1945 – 1990 there were numerous works of geometric levelling carried out at the present territory of the Republic of Croatia. These works are the basis for the new height system of the Republic of Croatia. The accuracy assessment of these works has been determined, with respect to the measuring accuracy, as well as to the benchmark height accuracy in accordance with the new definition of vertical datum and height system of the Republic of Croatia. 1. INTRODUCTION At the territory of the Republic of Croatia the extensive works on general geometric levelling were made in the period between 1945 and 1990. These are the following works: high accuracy levelling (NVT), precise levelling (PN), city levelling (GN), technical levelling of higher accuracy (TNPT) and technical levelling (TN). Within the scope of these works there were numerous levelling lines made and extensive bench mark fields established that cover, mostly adequately, the entire territory of Croatia pursuant to: geographic, traffic, economic and other characteristics of single areas of regions, and to financial, technical, material and organisational circumstances stipulating their execution. Bench mark fields and levelling lines are unified completely in a coherent system of state levelling network established on the classic hierarchy principle, i.e. following the orders of accuracy. The extensive works of general geometric levelling are well defined by the data contained in the archives of the State Geodetic Administration of Croatia. Following various orders of accuracy there were altogether 468 levelling lines made at the territory of Croatia encompassing about 23000 benchmarks. Individual orders of levelling contain: - 36 levelling lines of the First High Accuracy Levelling (INVT) and 45 levelling lines of the Second High Accuracy Levelling (IINVT) – I. order - 77 levelling lines of precise levelling – II.order - 49 levelling lines of the city levelling – II. order - 149 levelling lines of the technical levelling of higher accuracy – III. order - 112 levelling lines of technical levelling – IV. order. The above stated levelling works were made practically in the period between 1946 and 1973. After the year 1973 there have been no systematic general levelling surveying. The original data, the adjustment results, operational documentation (network sketches, levelling figure sketches, positional bench mark descriptions, lists of heights) and other data are stored in the archives of the State Geodetic Administration. At the beginning of the nineties and after the Republic of Croatia has been recognised as an independent and sovereign state, the work started on updating the inherited levelling networks and their usage in new circumstances. These works, carried out during the nineties, did not include relevelling and the renewal of benchmark fields due to high fieldwork costs (stabilisation, survey, etc.), but it is based on maximum usage of the archive data considering economic, financial and organisational infractructure (instruments, equipment, experts). Within the scope of these works a great amount of jobs has been carried out: - study on Updating the Levelling at the Territory of the Republic of Croatia has been made with the assessment of the inherited situation in state levelling networks given in it, as well as the proposal for improving this situation (Klak et al. 1992) - the proposal of the Book of Ordinances about the Levelling Works has been made (Klak et al. 1993) that has been used as a normative and technical basis for carrying out the works on levelling in general, i.e. making the revision of benchmark fields and of levelling networks * Predstavljeno na EUREF2002 simpoziju (Symposium of the IAG Subcommission for Europe – EUREF) održanom u Ponta Delgadi, Azori, Portugal, 5.-9.6.2002. godine. Objavljeno u zborniku radova Simpozija (Rožić, N.: Accuracy of geometric levelling networks at the terrritory of Croatia. Mitteilungen des Bundesamtes für Kartographie und Geodäsie, Band 29, EUREF Publication No. 12, Frankfurt am Main, 2003, 336-340). - 11 - the extensive and systematic field revision of benchmark fields at the territory of the Republic of Croatia has been made that are encompassed by the state levelling networks, and it has been defined for every single bench mark in the field and the field as a whole, how far it has been preserved or destroyed - the operational documentation referring to benchmark fields has been systematically revised, including: modernisation, updating in accordance with the results of field revision, production of new levelling line and network maps and of benchmark positional descriptions - extensive computing processing and measuring data adjustment of levelling has been made along with their resystemising and with the reference to the new vertical datum and fundamental levelling network, and new heights for all bench marks have been determined - operational data for benchmark fields have started to be published in special publications in edition of the State Geodetic Administration (Klak et al. 1994, Klak et al. 1998a, Rožić et al. 2001) - three new levelling lines of height accuracy levelling have been designed and surveyed (Koprivnica – Goričan, Virovitica – Terezino polje, Batina – Udvar) intended to connect the I. Order levelling networks between the Republic Hungary and the Republic of Croatia (Klak et al. 1995, Klak et al. 1997a, Klak et al. 2000) - geopotential and normal system of the Republic of Croatia has been defined and the height system of the Republic of Croatia has been connected with the United European Levelling Network – UELN (Klak et al. 1997, Klak et al. 1997b, Klak et al. 1998, Feil and Rožić 2000) - the proposal has been made to have a new vertical datum introduced into official usage HRVD71 – Croatian Vertical Reference Datum 1971 (Feil and Rožić 2000a) that has been evaluated by international advisers (Brockman et al. 2001) - the Study on Renewal and Maintenance of the Height System of the Republic of Croatia has been made accompanied by the analysis of the results obtained in the works carried out in the period from 1992 – 2000 and by the proposals for the works to be executed inevitably in the forthcoming period (Feil and Rožić 2001). One of the most important and previously mentioned topics is processing and adjustment of levelling networks intended for the determination of bench mark heights. The integral part of this processing is also the determination of accuracy estimation criteria. Since the processing has been made for the levelling lines at the entire territory of the Republic of Croatia, concrete indicators of levelling network accuracy have been obtained. - 2. ADJUSTMENT OF GEOMETRIC LEVELLING NETWORKS The adjustment of geometric levelling lines and networks at the territory of the Republic of Croatia was carried out gradually in the period between 1994 and 2000. It followed the field revision of benchmark fields, and it was based on archive documentation kept in the State Geodetic Administration of the Republic of Croatia and on the archives kept in few larger geodetic firms that had formerly executed some of these works. Levelling networks were adjusted in accordance with the hierarchy principle, i.e. by lower order networks referring to higher orders. As the reference for including the lower order networks (PN, GN, TNPT and TN), a new vertical datum of the Republic of Croatia has been adopted, as well as IINVT network as the fundamental levelling network (Rožić 2001), Fig. 1. Applying the function model of indirect regular non-correlated measurements the adjustments of networks have been made by the least squares method. Levelling networks and lines have been adjusted individually in a single levelling figures of IINVT, Fig. 1. In this way the data processing has been divided into a few phases. The results of data processing have been consequently published in a series of studies made at the Faculty of Geodesy, University of Zagreb. The works have been executed in the following phases: - the II. levelling loop IINVT – 1994 - I. levelling loop IINVT – 1995 - III. levelling loop IINVT – 1995 - VIII. levelling loop IINVT – 1996 - IV. levelling loop IINVT – the first part – 1996 - VI., XIV., XV. and XVI. levelling loop IINVT – 1997 - V. levelling loop IINVT – 1998 - IV. levelling loop IINVT – the second part – 1998 - III. and VIII. levelling loop IINVT - supplementations – 1999 - VIII. levelling loop IINVT - supplementation – 1999 - IX. levelling loop IINVT – 1999 - XII levelling loop IINVT – 1999 - VII. and XI. levelling loop IINVT and island levelling networks - 2000. - 12 - 14 FR3053 Varaždin 15 16 FR3020 Zagreb III 5 1 2 12 FR1029 Brajkovići BV MCXVII Bakar 11 10 BP82 Rovinj C46 Senj 21 9 I IV DCCLIII Virovitica A437 Novska CP695 Kostajnica 20 37 VIII C650 Okučani 44 41 18 BV11530 Daruvar 19 O362 Batina 17 C143 Pčelić 42 K274 43 Našice 38 FR3063 Strizivojna 22 MCCI Ž.Lokva CP317 Osijek 48 REPUBLIKA HRVATSKA II. NIVELMAN VISOKE TOČNOSTI 23 V 26 0 10 20 30 40 50 km Tumač znakova: 25 C162 Šibenik 31 čvorni reper VI BV14530 3 mareograf nivelmanski vlak MCCC Split PN167 30 br. nivel. vlaka XIV 35 C346 Opuzen 63 Geodetski Fakultet Sveučilišta u Zagrebu XV FR1098 XVI C620 Dubrovnik 4 A496 62 60 Fig. 1. Levelling network IINVT at the territory of the Republic of Croatia 3. ACCURACY ESTIMATION RESULTS FOR GEOMETRIC LEVELLING The accuracy of geometric levelling networks at the territory of the Republic of Croatia is given by the accuracy criteria "a posterior", i.e. by reference probable measurement errors and probable errors of network nodal benchmark heights determined on the basis of adjustment. They have been determined according to single levelling orders and levelling figures of IINVT. Apart from the adjustment of the fundamental levelling network, i.e. IINVT network (Rožić 1995), there have been altogether 127 adjustments of lower order geometric levelling networks being of various complexity (number of measurements and unknowns). The adjustment has been executed for individual orders as follows: - 16 precise levelling networks - 58 city levelling networks - 19 networks of technical levellings of increased accuracy - 34 technical levelling networks. The accuracy criteria "a posterior" are given in the table 1, divided in individual levelling figures of IINVT and individual levelling orders. The table contains probable reference errors of measurement uo and probable errors of nodal benchmark heights uH. There are always two probable errors of nodal benchmark heights given. The probable error of nodal bench mark height that has got the lowest amount (min.- mH) and the probable error of the bench mark height that has got the highest amount (max.- mH). The bench marks referring to these probable errors have the highest, i.e. the lowest height accuracy. These probable errors are indicators of height accuracies for all other benchmarks encompassed by the adjustment. Table 1. Accuracy estimation for measurements and benchmark heights IINVT FIGURE I. uo PN min.uH max.uH mm / km mm mm ± 0,79 ± 0,33 ±11,77 uo mm / km GN min.uH max.uH mm mm uo TNPT min.uH max.uH mm mm mm / km uo mm / km TN min.uH max.uH mm mm ± 1,86 ± 1,41 ± 7,09 ± 2,92 ± 0,26 ± 5,21 ± 1,87 ± 3,08 ± 7,77 II. ± 4,59 ± 6,04 ±35,15 ± 1,25 ± 0,23 ± 2,16 ± 3,20 ± 2,43 ± 8,53 III. ± 2,56 ± 1,61 ±10,01 ± 3,25 ± 0,47 ± 4,63 ± 3,97 ± 3,73 IV. ± 2,28 ± 3,67 ±10,23 ± 2,10 ± 1,03 ± 2,07 ± 6,55 ±12,09 - 13 - uo mm / km min.uH max.uH mm mm ± 3,89 ± 2,49 ± 8,72 ±14,25 ± 6,09 ± 1,21 ±14,31 ±12,09 ± 6,73 ± 6,59 ±16,53 V. ± 2,14 ± 2,44 ± 9,20 ± 2,31 ± 0,50 ± 2,37 VI. ± 2,03 ± 1,14 ± 6,06 ± 3,03 ± 0,31 ± 3,86 ± 8,18 ± 3,57 ± 3,48 ± 6,50 VIII. ± 2,47 ± 2,29 ± 9,14 ± 2,75 ± 0,55 ± 4,11 ± 5,60 ± 2,47 ±11,29 IX. ± 1,15 ± 1,24 ± 9,59 ± 4,84 ± 0,57 ± 4,73 VII. XI. XII. ± 1,15 ± 1,24 ± 9,59 XIV. ± 1,65 ± 4,51 ± 4,77 XV. ISLAND ± 3,33 ± 1,76 ± 5,10 ± 0,51 ± 7,17 ± 1,22 ± 1,33 ± 3,35 ± 0,89 ±19,20 ± 2,27 ± 5,41 ± 5,52 ± 6,95 ± 4,10 ± 7,83 ± 3,33 ± 4,48 ± 7,51 ± 8,05 ± 4,62 ±23,67 ± 3,96 ± 2,99 ±12,03 ± 1,47 ± 5,55 ± 6,35 ±11,85 ±16,41 ±27,93 ± 3,41 ± 1,08 ± 5,98 ±25,92 On the basis of the data in the table 1 one can determine representative values of accuracy criteria "a posterior" referring to single geometric levelling orders for the entire territory of the Republic of Croatia. These accuracy criteria "a posterior" are given in the table 2. Table 2. Accuracy estimation for measurements and benchmark heights IINVT uo FIGURE CROATIA PN uo GN uo TNPT uo TN uo min.uH max.uH min.uH max.uH min.uH max.uH min.uH max.uH min.uH max.uH mm / km mm mm mm / km mm mm mm / km mm mm mm / km mm mm mm / km mm mm ± 0,79 ± 0,33 ±11,77 ± 2,53 ± 1,14 ±35,15 ± 2,70 ± 0,23 ± 7,17 ± 3,42 ± 2,43 ±14,25 ± 6,61 ± 0,89 ±27,93 4. CONCLUSIONS On the basis of the accuracy estimation data given in the previous chapter, several conclusions can be made. First of all, based on the table 2, it can be concluded that accuracies of measurement achieved at the entire territory of the Republic of Croatia in all orders of levelling mostly meet the accuracy criteria defined in advance. The measuring accuracy is also logically reduced from the higher order networks to lower orders. The allowed values of probable reference measurement errors for single geometric levelling orders are: - high accuracy levelling, uo = ±1mm / km , - precise and city levelling, uo = ±2mm / km , - higher accuracy technical levelling, uo = ±5mm / km , - technical levelling, uo = ±8mm / km . With regard to measuring accuracy, the precise and city levelling are partly exceptional, because their accuracy is somewhat lower than it is allowed by the accuracy criteria. The accuracy estimation data given in the table 1 show that there was no completely homogeneous measurement accuracy achieved at the territory of the Republic of Croatia within the frame of single geometric levelling orders. It is obvious that in some parts of its territory, i.e. in single IINVT figures, the measuring accuracy is different within the frame of the same levelling orders, and sometimes even considerably lower than allowed. The origins of this unhomogeneity are connected primarily with the surveying quality, measuring procedures, instruments and other conditions. On the other hand, they are partly the consequence of various time epochs that individual levelling orders belong to. The height benchmark accuracy can be considered satisfactory and logical related to the measuring accuracy. In the whole precise levelling, taking the entire state territory into account, the nodal bench mark with the lowest height accuracy has the probable error of ± 35 mm, in the city and higher accuracy technical levelling of ± 7mm, i.e. of ± 14 mm and in technical levelling of ± 28mm. A great number of benchmarks has got a considerably higher height accuracy which can be very well seen from the data in table 1. In this matter it should be taken into consideration that the accuracies of bench mark heights are partly stipulated by the manner of network adjustment and by the fact that bench marks in higher order levelling being fixed. The achieved measuring accuracies and height accuracies of benchmarks are surprising to a certain extent. Namely, taking into consideration the fact that the observation material was gathered in long period of time (surveying in different time epochs), measured with different instruments, procedures and accessories, and mostly collected in very modest material and technical conditions (the period between 1945 and 1963), there has been a relatively satisfactory result obtained. Regardless of some - 14 - deficiencies contained by all means in the works of the geometric levelling, they still have adequate use value, especially for practical purposes. Anyway, at the moment the Republic of Croatia does not have higher quality levelling works at its disposal that could be used, and the new systematic works on the renewal of bench mark fields and updating of geometric levelling state networks has not yet started. REFERENCES Brockmann, E., Harsson, B.G., Ihde, J. (2001): Geodetic Reference System of the Republic of Croatia, Consultants Final Report on Horizontal and Vertical Datum Definition, Map projection and Basic Networks, Tehnical Report, June 2001. Feil, L., Rožić, N. (2000): UELN geopotencijalni i normalni visinski sustav Republike Hrvatske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Feil, L., Rožić, N. (2000a): Prijedlog službenog visinskog datuma Republike Hrvatske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Feil, L., Rožić, N. (2001): Studija o obnovi i održavanju visinskog sustava Republike Hrvatske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1992): Studija o sređivanju geometrijskog nivelmana na području Republike Hrvatske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1993): Pravilnik o radovima geometrijskog nivelmana – prijedlog, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1994): Podaci o reperima - knjiga 1, Državna geodetska uprava Republike Hrvatske, Zagreb, 1994. Klak, S., Feil, L., Rožić, N. (1995): Povezivanje nivelmana visoke točnosti Republike Hrvatske, Republike Slovenije i Republike Mađarske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1997): Ispitivanje mogućnosti određivanja geopotencijalnih visina, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1997a): Povezivanje nivelmana visoke točnosti Republike Hrvatske i Republike Mađarske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1997b): Precise levelling data of the Republic of Croatia for the United European Levelling Network, Državna geodetska uprava Republike Hrvatske, Zagreb. Klak, S., Feil, L., Rožić, N. (1998): Connecting of levelling of high accuracy between the Republic Hungary and the Republic of Croatia in geopotential height system. Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1998a): Podaci o reperima - knjiga 2, Državna geodetska uprava Republike Hrvatske, Zagreb. Klak, S., Feil, L., Rožić, N. (2000): Povezivanje nivelmana visoke točnosti Republike Hrvatske i Republike Mađarske - drugi dio, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Rožić N. (1995): Ispitivanje slučajnih i sistematskih pogrešaka u geometrijskom nivelmanu, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb, doktorska disertacija, Zagreb. Rožić, N., Feil, L., Pavičić, S. (2001): Podaci o reperima - knjiga 3, Državna geodetska uprava Republike Hrvatske, Zagreb. Rožić, N. (2001): Fundamental levelling networks and height datums at the territory of the Republic of Croatia, Acta Geodaetica et Geophysica Hungarica, Budapest, Vol. 36 (2), 231-243. - 15 - - 16 - STABILNOST MJERNOG SUSTAVA SCINTREX HGI-2 GRAVIMETRA* Željko Hećimović, Danko Markovinović SAŽETAK U radu je ispitivano ponašanje mjernog sustava Scintrex CG-3M, HGI-2 gravimetra. Hod je glavna karakteristika stabilnosti mjernog sustava gravimetra. Ispitivanje je obavljeno na osnovi promjena hoda u periodu od dva mjeseca, kontinuiranog mjerenja u periodu od devet dana i mjerenja u periodu od jednog dana. Nakon uzimanja u obzir popravaka i korekcija u realnom vremenu preostali hod je sveden -7 -2 na 1·10 ms . Na tako dobiven signal primijenjena je wavelet analiza i to Coifmanov wavelet petog reda. Izvršena je multirezolucijska analiza signala do trećeg nivoa. Stabilnost mjernog sustava gravimetra je analizirana s obzirom na frekvencije i amplitude aproksimacije i detalja signala mjerenja. Za rezidualna polja detalja dani su osnovni pokazatelji statističke varijabilnosti. KLJUČNE RIJEČI hod gravimetra, wavelet analiza, multirezolucijska analiza, aproksimacija, detalj ABSTRACT In this work is behavior of Scintrex CG-3M, HGI-2 gravimeter analyzed. Drift is the main characteristic of stability of gravimeter measurement system. Analysis are made considering drift changes in period of two months, continuous measurements of nine days and measurements of one day. -7 -2 Remaining daily drift is after using real time corrections 1·10 ms . Wavelet analysis is applied on oneday measurements. Signal is analyzed with Coifman wavelet of the fifth order. Multiresolutin decomposition is developed to the third level. Stability of gravimeter measurement system is analyzed considering frequencies and amplitudes of approximation and details. The main parameters of statistical variability of details are presented. KEYWORDS drift, wavelet analysis, multiresolution analysis, approximation, detail 1. UVOD -8 -2 Scintrex CG-3M relativni gravimetar ima rezoluciju očitanja 10 ms . Da bi mjerili tako fine vrijednosti razlika ubrzanja sile teže, promjene položaja mjerne mase gravimetra se moraju odrediti na -11 10 m, što je promjer atoma. Tako veliki zahtjev na mjerni sustav pretvara gravimetar u prijenosni mjerni laboratorij kod kojeg moramo voditi brigu i o najmanjim varijabilnim utjecajima koji se javljaju tijekom mjerenja. Stabilnost mjernog sustava kao jedna od osnovnih karakteristika gravimetra je karakterizirana njegovim hodom. Prije provođenja mjerenja CG-3M gravimetar treba proći niz procedura da bi bio spreman za rad. Rad HGI-2 gravimetra je redovito praćen (Hećimović 2002) i slijedeće procedure su provedene nad njim: 1) temperaturna kompenzacija, 2) određivanje hoda gravimetara i podešavanje sata hoda gravimetara, 3) određivanje nule senzora nagiba gravimetra, 4) određivanje osjetljivosti senzora nagiba gravimetra. Mjerenja gravimetrom su opterećena vremenskim utjecajima koji su nepoželjni u signalu mjerenja. Scintrex CG-3M gravimetri imaju mogućnost korigiranja mjerenja u realnom vremenu za temperaturu mjernog senzora, a priori hod gravimetra, promjenu nagiba gravimetra, Zemljine plimne valove i konstantu gravimetra. Osim toga Scintrex CG-3M gravimetar ima mogućnost izbacivanja grubih mjerenja i primjenu seizmičkog filtra koji otklanja ili umanjuje mikro seizmičke utjecaje (Scintrex 1998). * Predstavljeno na Znanstveno-stručnom simpoziju u povodu 40. godišnjice samostalnog djelovanja Geodetskog fakulteta Sveučilišta u Zagrebu, održanom u Zagrebu 26.9.2002. godine. Objavljeno u Zborniku radova Simpozija (Hećimović, Ž., Markovinović, D.: Stabilnost mjernog sustava Scintrex HGI-2 gravimetra. Zbornik radova znanstveno-stručnog simpozija povodom 40. godišnjice samostalnog djelovanja Geodetskog fakulteta Sveučilišta u Zagrebu, Geodetski fakultet, Zagreb, 2002). - 17 - 2. STABILNOST MJERNOG SUSTAVA GRAVIMETRA Hod gravimetra je promjena nule mjernog sustava s vremenom i jedna je od osnovnih karakteristika stabilnosti mjernog sustava (Torge 1989). Na osnovi stabilnosti mjernog sustava zaključujemo kako često moramo ponavljati mjerenja na referentnoj točci da bi mogli pouzdano odrediti hod na temelju diskretnih mjerenja. Za novije instrumente je promjena hoda s vremenom veća, a sa starenjem mjerni sustav postaje stabilniji, a hod pravilniji. Prvo određivanje hoda HGI-2 gravimetra izvršeno je u tvrtki Scintrex i iznosio je 2,12 mGal/dan. Stabilnost mjernog sustava HGI-2 gravimetra je ispitivana na temelju promjena hoda u periodu nešto kraćem od dva mjeseca, na temelju kontinuiranih mjerenja od devet dana i na osnovi mjerenja u intervalu od 24 sata. Nakon provedenih prethodno navedenih procedura i koristeći navedene korekcije signala mjerenja u realnom vremenu dobiveni su mjerni signali koji su korišteni u ovoj analizi. Naknadnom obradom i analizom podataka mjerenja mogu se dobiti bolji rezultati jer se mjerenja mogu naknadno osloboditi utjecaja varijacije tlaka zraka, loading efekta, Chandler Wobble efekta, dugoperiodičnih i godišnjih Zemljinih plimnih valova, Zemljinih plimnih valova s obzirom na krutu i elastičnu Zemlju, utjecaja varijacija podzemnih voda, mikro seizmike, tektonike ploča, lokalnog premještanja masa, postglacijalnog vertikalnog uzdizanja, i dr. -7 -2 Na sl. 1 su prikazana mjerenja za period od 24 sata. Očitanja variraju u rasponu od 2,9·10 ms , -7 a preostali dnevni hod je 1·10 -2 ms . Prema propisima za državni premjer gravimetrijske mreže -7 -2 Njemačke promjena signala gravimetra koji se koristi mora biti u području 1·10 ms . Taj kriterij se odnosi na naknadno obrađeni signal, a ne na signal dobiven u realnom vremenu koji je ovdje prikazan. Naknadnom obradom bi mogli poboljšati signal prikazan na sl. 1, ali u tom bi slučaju imali lošiji uvid u stabilnost mjernog sustava gravimetra. Signal prikazan na sl. 1 će biti detaljno analiziran u poglavlju 4. Na sli. 2 su prikazana kontinuirana mjerenja gravimetrom HGI-2 u periodu od devet dana. Kao što se sa slike vidi dominira negativan paraboličan preostali hod gravimetra. U tablici 1 su prikazane promjene hoda za intervale od 24 sata. Slika 1. Očitanja gravimetra za interval mjerenja od jedan dan Slika 2. Očitanja gravimetra za interval mjerenja od devet dana. Tablica 1. Preostali hod u periodima po 24 sata za mjerenja prikazana na slici 2. Na osnovi podataka u tablici 1 uočava se povećavanje preostalog hoda u prvom danu, a u sljedećim danima dolazi do nelinearnog smanjivanja hoda. Treba naglasiti da je promatrani signal dobiven u realnom vremenu, a on se naknadnom obradom može poboljšati. - 18 - Da bi dobili cjelovitiji uvid u ponašanje mjernog sustava HGI-2 gravimetra periodično je određivan hod (Hećimović 2002). Glavni rezultati su dani u tablici 2. Za prva tri određivanja je za a priori dnevni hod korištena vrijednost 2,12 mGal/dan, a za daljnje vrijednosti je za a priori vrijednost hoda korištena prethodno određena vrijednost. Tablica 2. Pregled hoda gravimetra HGI-2. Iz tablice 2 se vidi da dominira smanjivanje vrijednosti hoda. Na slici 3 su grafički prikazane vrijednosti iz tablice 2 po danima od prvog određivanja hoda, gdje se jasno uočava smanjenje vrijednosti hoda. Slika 3. Promjena hoda gravimetra HGI-2 po danima. Na osnovi izloženog višednevnog kontinuiranog mjerenja i periodičnog određivanja hoda uočava se isti proces opuštanja mjernog sustava gravimetra. Razlog ne linearnom hodu u dužim mjerenjima je najvjerojatnije mirovanje instrumenta i za očekivati je da će s vremenom doći do većeg stupnja stabilnosti mjernog sustava i hoda. Naravno, hod će uvijek biti prisutan zbog promjena fizikalnih svojstava mjernog sustava s vremenom. Period u kojem su izvršena mjerenja za ovu analizu je nešto manje od dva mjeseca. To je kratko vremensko razdoblje za izvršiti dugoperiodičnu analizu stabilnosti mjernog sustava gravimetra, naročito jer se radi o početku praćenja stabilnosti mjernog sustava HGI-2 gravimetra. Prema propisima za državni premjer gravimetrijske mreže Njemačke hod gravimetara koji se primjenjuju za premjer državne mreže treba biti praćen najmanje šest mjeseci. Da bi dobili bolji uvid u ponašanje mjernog sustava gravimetra provest ćemo naknadnu analizu -7 -2 signala mjerenja. Područje interesa naknadne analize je 1·10 ms u kojem se kriju utjecaji preostalih signala instrumenta (nagiba instrumenta, temperaturne kompenzacije i temperaturnih šokova, magnetizma, variranja napona, mehaničkih šokova) i preostali, prethodno nabrojani, utjecaji na signal ubrzanja sile teže. U naknadnoj obradi je primijenjena wavelet analiza na signal dnevnog mjerenja prikazanog na slici 1. 3. WAVELET ANALIZA Wavelet (valići) analiza je relativno novi dio matematike koji se još intenzivno razvija. Wavelet se prvi put spominje 1909. godine u radu Alferda Haara, a intenzivno se počinje razvijati u matematičkim krugovima osamdesetih godina prošlog stoljeća. Zbog mogućnosti koje pruža, wavelet analiza se sve više primjenjuje u rješavanju znanstvenih i stručnih problema. Wavelet analizom otvoreni su novi pristupi matematičkoj percepciji realnosti. Ona otvara nove mogućnosti filtriranja signala, rješavanja parcijalnih diferencijalnih jednadžbi, analize podataka, omogućuje jednostavnu primjenu multirezolucijske analize i dr. Wavelet analiza nalazi sve više svoju primjenu i u geodeziji. Neki od primjera praktične primjene waveleta u geodeziji su otkrivanje prekida GPS signala, prikaz digitalnog modela reljefa, multirezolucijska analiza polja ubrzanja sile teže, primjena pri određivanju dužine dana (Schmidt i Schuh 1999), analiza i prikaz globalnog geopotencijalnog modela (Schmidt i dr. 2000). Od posebnog interesa za analizu i modeliranje geodetskih podataka je područje primjene sfernih waveleta (Schmidt 2001). Ovdje je dan kratak osvrt na wavelet analizu. Više o wavelet analizi se može naći u Antoniadis i Oppenheim (1995), Resnikoff i Wells (1998), Torrence i Compo (1998). Wavelet analiza je proširenje Fourierove analize, u kojoj operacija diskretne transformacije ima jednu od vodećih uloga. Kao i brza Fourierova transformacija (Fast Fourier Transformation, FFT) diskretna wavelet transformacija (DWT) je linearna operacija. Jedna od glavnih razlika između FFT i DWT je u tome što FFT koristi sinus i kosinus funkcije kao funkcije baze u novoj domeni u koju se funkcija preslikava, a kod DWT funkcije baze su - 19 - složenije ali pružaju veće mogućnosti analiziranja. Za funkcije bazisa u wavelet analizi može se izabrati beskonačno mnogo funkcija, ali samo neke omogućuju lokalizaciju u vremenu, što sinus i kosinus funkcije ne omogućuju. Osim lokalizacije u vremenu, funkcija baze mora omogućavati i lokalizaciju frekvencije, odnosno skale, što kod FTT-a osiguravaju sinus i kosinus funkcije. Za razliku od Fourierove analize koja koristi vrijeme i frekvenciju kao osnovu predstavljanja signala, wavelet analiza koristi frekvenciju i skalu. Mogućnost lokalizacije frekvencije je bitna prednost wavelet analize u odnosu na Fourierovu. Zbog mogućnosti vremenske lokalizacije promatrane frekvencije wavelet analizom je moguće obrađivati i ne stacionarne signale, što nije slučaj kod metode FFT-a. U wavelet analizi centralnu ulogu ima wavelet funkcija, često nazivana "mother" wavelet, i funkcija skaliranja, ako postoji. Wavelet funkcije možemo podijeliti u familije: osnovne wavelete, regularne u beskonačnosti, ortogonalne i biortogonalne. Wavelet funkcije su dobivene na osnovi početne osnovne funkcije primjenom dilatacije (rastezanje) i translacije (Antoniadis i Oppenheim 1995). Generalno je wavelet funkcija kompleksna i vezana je uz skup kompleksnih brojeva Z. U ovom radu su od posebnog interesa wavelet funkcije s ortonormalnom bazom. Pri tome za funkciju ψ, familija (ibid.), 2 2 definira ortonormiranu bazu u realnoj domeni L (R). Aproksimacija od L (R) se može definirati pomoću 2 zatvorenih podprostora Vj, j œ Z od L (R). Ortonormirani bazis od Vj je definiran familijom {φj,k : k œ Z} gdje je razvučen i translatiran oblik funkcije skaliranja. Multirezolucijska analiza definira ortogonalno rastavljanje 2 L (R). Ako definiramo Wj kao ortogonalni komplement od Vj u Vj+1, dobivamo novu sekvencu {Wj : j œ Z} zatvorenih međusobno ortogonalnih podprostora. Pri tome je svaki Wj dilatacija od W0 i njihova suma je 2 jednaka L (R). Tada familija formira ortonormiranu bazu svakog prostora detalja Wj. Ako je multirezolucijska analiza regularna tada wavelet ψ ima momente jednake nuli do reda r, tj. Prednost većeg broja momenata jednakih nuli za ψ je da su wavelet koeficijenti finije skale jednaki nuli na dijelovima gdje je funkcija glatka. Ali povećanjem broja momenata jednakih nuli se gubi na lokalnoj karakteristici analize te broj momenata jednakih nuli ne može rasti u beskonačnost već do broja koji dopuštaju lokalne karakteristike signala. Moguće je konstruirati ortogonalni wavelet tako da funkcija skaliranja φ ima N-1 momenata jednakih nuli, tj. da zadovoljava Wavelet koji zadovoljava gornje uvijete je konstruirala matematičarka Ingrid Daubechies i nazvan je Coifmanov wavelet po Ronaldu Coifmanu na čiji prijedlog je konstruiran (Antoniadis i Oppenheim 1995). Wavelet analizom izvodimo dekompoziciju signala na dva signala: aproksimaciju i detalj. Signal aproksimacije zadržava glavninu energije početnog signala ali je šum reduciran, a detalj sadrži preostali dio viših frekvencija. Dekompozicija se može računati u više nivo, te za svaki nivo dobivamo aproksimaciju i detalj na osnovi signala iz prethodnog nivoa. Analizu signala na više nivoa u raznim rezolucijama nazivamo multirezolucijska analiza. Teoretski se postupak grananja može provesti u beskonačnost, ali se prilikom praktičnog računanja ograničavamo do nivoa koji sadrži korisne informacije. Prilikom provođenja wavelet analize računamo koeficijente C(a,b) za signal s(t) na temelju wavelet funkcije ψ pomoću izraza (ibid.) - 20 - j j 2 gdje a = 2 definira promjenu skale, a b=k2 translaciju uz uvjet j, k œ Z . Detalj za nivo j dobivamo po izrazu Aproksimaciju možemo definirati kao grubi dio detalja a rekonstrukciju signala možemo dobiti po izrazu Aproksimacije na nivoima J-1 i J možemo povezati izrazom 4. WAVELET ANALIZA MJERNOG SIGNALA GRAVIMETRA U ovom radu je zbog svojih osobina pri obradi signala gravimetra korišten Coifletov wavelet petog reda iz familije ortogonalnih waveleta. Glavni predstavnici ove familije waveleta su Daubechiesov, Symletov i Coiflet wavelet. Neke od glavnih osobina Coiflet waveleta petog reda su ortogonalnost analize, postojanje funkcije skaliranja, mogućnost kontinuirane i diskretne wavelet transformacije, te približna simetričnost. Coifletova wavelet funkcija ψ ima 2N momenata jednaka nuli, a funkcija skaliranja φ ima 2N-1 momenata jednaka nuli (Resnikoff i Wells 1998). Coifmanov wavelet je zadan u numeričkom obliku i prikazan je na slici 4, a na slici 5 prikazana je pridružena funkcija skaliranja. Slika 4. Coifmanov wavelet petog reda Slika 5. Funkcija skaliranja za Coifmanov wavelet 5 reda. Do kojeg nivoa možemo provesti multirezolucijsku dekompoziciju ovisi o prirodi signala. U ovom radu je multirezolucijska dekompozicija provedena do trećeg nivoa, što je prikazano na slici 6. Slika 6. Wavelet multirezolucijsko grananje. Multirezolucijska dekompozicija signala sa slike 1 je prikazana na slici 7. Na apcisnoj osi su nanijete epohe mjerenja koje su trajale 60 sekundi. Sa slike 7 se uočava da se povećavanjem nivoa dekompozicije smanjuje količina informacija u preostalom detalju. Aproksimacija preuzima trend i dio vezan uz glavnu energiju signala. Aproksimacija je oslobođena visoko frekventnog dijela te se promjene signala s kraćim periodama i poludnevnim - 21 - periodama jasnije uočavaju. Kraće periode imaju trajanje od 10 do 30 minuta. One su nepravilne i imaju amplitude manje od 0,01 mGal. One su najvjerojatnije prouzrokovane duže periodičkim mikroseizmičkim utjecajem na gravimetar. Promjene signala s poludnevnim periodama imaju uglačan karakter. Njihov uzrok može biti instrumentalni ili ostatak utjecaja signala koji djeluju na ubrzanje sile teže, a nisu kompenzirani u realnom vremenu. Slika 7. Aproksimacija A3 i detalji D1, D2 i D3. Detalji nam daju uvid u kratko periodični dio signala i njima možemo analizirati finije strukture signala koje imaju karakteristike šuma. Trajanje kratko periodičnih promjena za detalj D1 je uglavnom na nivou promjene za jednu epohu mjerenja od 60 sekundi, za detalj D2 četiri epohe i za D3 nešto manje od deset epoha. Raspon amplituda za detalj D1 iznosi 0,017 mGal, za D2 0,015 mGal i za D3 0,009 mGal. Smanjivanje raspona ostatka informacija u detalju s povećanjem dekompozicijskog nivoa je 0,002 mGala između prvog i drugog nivoa i 0,006 mGal između drugog i trećeg nivoa. Pokazatelji statističke varijabilnosti za detalje su prikazani na slici 8 i tablici 3. Tablica 3. Osnovni pokazatelji statističke varijabilnosti detalja D1, D2 i D3. Slika 8. Histogrami detalja D1, D2, D3. - 22 - Iz pokazatelja statističke varijabilnosti signala (tablica 3) vidi se da su signali detalja centrirani. Za detalje D1, D2 i D3 su izračunani spektri gustoće snage detalja (v. sliku 9). Slika 9. Spektri gustoće snage detalja D1, D2 i D3. Na osnovi spektara gustoće snage uočljivo je da dolazi do smanjenje frekvencija spektra detalja s povećanjem multirezolucijsko dekompozicijskog nivoa. 5. ZAKLJUČAK -7 -2 Preostali hod gravimetra HGI-2 je korekcijama u realnom vremenu sveden na 1·10 ms , ali mjerni sustav gravimetra pokazuje opuštanje što se uočava u kontinuiranim višednevnim mjerenjima i kod određivanja hoda u periodu od nešto manje od dva mjeseca. Razlog je najvjerojatnije višegodišnje mirovanje gravimetra. Za očekivati je da će vremenom doći do višeg stupnja stabilizacije mjernog sustava gravimetra. Primjenom wavelet analize je dobivena aproksimacija na trećem multirezolucijskom nivou u kojoj se uočavaju promjene mjernog sustava u kraćim periodama u trajanju od 10 do 30 minuta i poludnevnim periodama. Promjene u kraćim periodama imaju amplitude manje od 0,01 mGal i najvjerojatnije su prouzrokovane duže periodičkim mikroseizmičkim utjecajem na gravimetar, dok uzrok promjena s poludnevnim periodama može biti instrumentalni ili ostatak utjecaja prirodnih signala koji djeluju na ubrzanje sile teže, a nisu kompenzirani u realnom vremenu. Raspon amplituda za detalj D1 iznosi 0,017 mGal, za D2 iznosi 0,015 mGal i za D3 iznosi 0,009 mGal. Područje frekvencija se u spektrima gustoće snage za detalje smanjuje s povećavanjem nivoa multirezolucijske dekompozicije. Ovo je početak praćenja stabilnosti mjernog sustava gravimetra HGI-2. Stvoreni su uvjeti za njegovo detaljno praćenje i analizu, a to je neophodno da bi se rezultati mjerenja mogli pravilno interpretirati. LITERATURA Antoniadis, A., G. Oppenheim (Ed.) (1995): Wavelet and Statistics. Springer Verlag, New York, Berlin, Heidelberg. Hećimović, Ž. (2002): Izvještaj o praćenju rada HGI-2 gravimetra. Hrvatski geodetski institut. Resnikoff, H. L., R. O. Wells (1998): Wavelet Analysis. Springer, New York, Berlin, Heidelberg. Schmidt, M., H. Schuh (1999): Frequency-Dependent Phaes Lags between LOD- and AAM- Variations Detected by Wavelet Analysis. www.dgfi.badw.de. Schmidt, M., W. Martinez, J. Florez (2000): General Scheme for the Computation of Regional Geoid Undulations Using Spherical Wavelets. www.dgfi.badw.de. Schmidt, M.(2001): Computation of Geoid Undulations from Gravity Anomalies by Means of Scintrex (1998): CG-3/3M Gravity meter, User's Guide, 1998. Spherical Wavelets. Poster on the IAG 2001 Scientific Assembly, 2. - 8.9.2001. Budapest. Torge, W. (1989): Gravuimetry. Walter de Gruyter, Berlin, New York. Torrence, C., G.P. Compo (1998): A Practical Guide to Wavelet Analysis. Bulletin of the American Meteorological Society, 61-78. - 23 - - 24 - TOČNOST VISINSKE OSNOVE GEOMETRIJSKOG NIVELMANA NA TERITORIJU REPUBLIKE HRVATSKE* Nevio Rožić SAŽETAK U razdoblju 1945.–1990. godine izvedeni su na današnjem teritoriju Republike Hrvatske brojni radovi geometrijskih nivelmana različitih redova točnosti. Ti su radovi osnova novog visinskog sustava Republike Hrvatske. U ovom se radu navode podaci i analize ocjene točnosti tih radova u pogledu točnosti mjerenja i visinske točnosti repera, u suglasju s novom definicijom visinskog datuma i visinskog sustava Republike Hrvatske predloženog za uvođenje u službenu uporabu. KLJUČNE RIJEČI geometrijski nivelman, nivelmanske mreže, točnost mjerenja ABSTRACT In the period from 1945 till 1990 significant and extensive works on the geometric levelling of all orders were carried out at the territory of the Republic of Croatia. This works serve as basis of new height system of the Republic of Croatia. In this paper accuracy data and accuracy analysis of this works are presented in wiew of measurement accuracy and bench-mark height accuracy accordingly with new definition of height datum and height system of the Republic of Croatia proposed for official usage. KEYWORDS geometric levelling, levelling networks, measurement accuracy 1. UVOD Na teritoriju Republike Hrvatske izvedeni su u razdoblju od 1945. do 1990. godine obimni radovi generalnog geometrijskog nivelmana. To su radovi: nivelmana visoke točnosti (NVT), preciznog nivelmana (PN), gradskog nivelmana (GN), tehničkog nivelmana povećane točnosti (TNPT) i tehničkog nivelmana (TN). U sklopu tih radova izvedeni su brojni nivelmanski vlakovi i ustrojena su obimna polja repera. Dio je vlakova izveden u obliku klasičnih linijskih vlakova, dok je dio vlakova izveden u obliku većih i složenijih nivelmanskih mreža, posebno gradskih i tehničkih nivelmana. Tim je vlakovima, uglavnom primjereno, pokriven cjelokupan teritorij Hrvatske sukladno: geografskim, prometnim, ekonomskim i drugim karakteristikama pojedinih područja ili regionalnih cjelina te financijskim, tehnološkim, materijalnim i organizacijskim prilikama koje su uvjetovale njihovu izvedbu. Polja repera i nivelmanski vlakovi koji ih povezuju, objedinjeni su u cjeloviti sustav državne nivelmanske mreže geometrijskog nivelmana ustrojene na klasičnom hijerarhijskom načelu, tj. po redovima točnosti. Polja repera čine materijalnu osnovu visinskog sustava koji je na teritoriju Hrvatske služio i još uvijek služi za rješavanje stručnih i znanstvenih geodetskih zadaća. Obimnost radova generalnog geometrijskog nivelmana dobro definiraju podaci sadržani u arhivu Državne geodetske uprave Republike Hrvatske. U različitim redovima točnosti izvedeno je na teritoriju Hrvatske ukupno 468 nivelmanskih vlakova, kojima je obuhvaćeno približno 23000 repera. Pojedinim redovima geometrijskog nivelmana pripada: - 36 nivelmanskih vlakova Prvog nivelmana visoke točnosti (INVT) i 45 nivelmanskih vlakova Drugog nivelmana visoke točnosti (IINVT) – I. red, - 77 nivelmanskih vlakova preciznog nivelmana – II.red, - 49 nivelmanskih vlakova gradskog nivelmana – II. red, - 149 nivelmanskih vlakova tehničkog nivelmana povećane točnosti – III. red, - 112 nivelmanskih vlakova tehničkog nivelmana – IV. red. * Predstavljeno na Znanstveno-stručnom simpoziju u povodu 40. godišnjice samostalnog djelovanja Geodetskog fakulteta Sveučilišta u Zagrebu, održanom u Zagrebu 26.9.2002. godine. Objavljeno u Zborniku radova Simpozija (Rožić, N.: Točnost visinske osnove geometrijskog nivelmana na teritoriju Republike Hrvatske. Zbornik radova znanstveno-stručnog simpozija povodom 40. godišnjice samostalnog djelovanja Geodetskog fakulteta Sveučilišta u Zagrebu, Geodetski fakultet, Zagreb, 2002, 105-115). - 25 - Navedeni nivelmanski radovi uglavnom su izvedeni u razdoblju od 1946. do 1973. godine, jer nakon 1973. godine, tj. trenutka dovršenja izmjere IINVT, nije više bilo sustavne generalne nivelmanske izmjere. Radovi su u cjelini oslonjeni na visinski sustav bivše Austro-Ugarske monarhije (visinski datum, vrsta visina). Jedina iznimka su radovi IINVT koji su trebali poslužiti za definiranje okosnice novog visinskog sustava bivše Jugoslavije. Također, nakon 1973. godine nisu obavljani nikakvi sustavni radovi obnove polja repera, odnosno reniveliranja ili osuvremenjivanja nivelmanskih vlakova i mreža. Izvorni podaci mjerenja, uporabljen instrumentarij, metode rada, tehnički normativi, rezultati računske obrade mjerenja, rezultati izjednačenja, uporabna dokumentacija (skice mreža, skice vlakova, položajni opisi repera, popisi visina) i drugi podaci, pohranjeni su u arhivu Državne geodetske uprave. Iako u potpunosti arhivski necjeloviti te sistematizirani i tehnološki pohranjeni na način primjeren trenutku njihovog nastanka, ovi podaci su i danas uporabljivi i mogu se koristiti za različite namjene. Početkom devedesetih godina, a nakon osamostaljenja i stjecanja suvereniteta Republike Hrvatske, pristupilo se sustavnim radovima geometrijskog nivelmana sa svrhom sređenja naslijeđene visinske osnove i njene uporabe u novim okolnostima. Ovi radovi, izvedeni tijekom devedesetih godina, nisu obuhvatili reniveliranje i obnovu polja repera zbog visoke cijene koštanja terenskih aktivnosti (stabilizacija, izmjera i dr.), već su se obzirom na ekonomske, financijske, organizacijske (instrumentarij, oprema, stručnjaci) i druge uvjete temeljili na maksimalnoj uporabi postojećih (arhivskih) podataka geometrijskog nivelmana, odnosno malim dijelom na izvedbi novih nivelmanskih vlakova. U sklopu tih radova obavljen je opsežan posao koji se sažeto može objediniti sljedećim cjelinama: - izrađena je Studija o sređivanju geometrijskog nivelmana na području Republike Hrvatske u kojoj je ocijenjeno naslijeđeno stanje državnih nivelmanskih mreža i dan prijedlog za poboljšanje tog stanja (Klak i dr. 1992), - izrađen je prijedlog Pravilnika o radovima geometrijskog nivelmana (Klak i dr. 1993) koji je poslužio kao normativno-tehnička osnova za obavljanje radova geometrijskog nivelmana općenito, odnosno obavljanje revizije polja repera i nivelmanskih mreža, - obavljena je opsežna i sustavna terenska revizija svih polja repera na teritoriju Republike Hrvatske obuhvaćenih državnim mrežama geometrijskog nivelmana te je utvrđeno, za svaki pojedini reper polja i polja repera u cjelini, stanje očuvanosti i uništenosti, - obavljena je sustavna revizija uporabne dokumentacije polja repera, uključujući: osuvremenjivanje, usklađivanje s rezultatima terenske revizije, izradu novih preglednih karata vlakova i mreža te položajnih opisa repera, - obavljena je opsežna računska obrada i izjednačenje podataka mjerenja geometrijskih nivelmana, uz njihovu presistematizaciju i oslanjanje na novi visinski datum i temeljnu nivelmansku mrežu te su određene nove nadmorske visine za sve repere (Klak i dr. 1994, Klak i dr. 1995., Klak i dr. 1995a, Klak i dr. 1996, Klak i dr. 1996a, Klak i dr. 1997a, Klak i dr. 1998a, Klak i dr. 1998b, Rožić i dr. 1999, Klak i dr. 1999, Klak i dr. 1999a, Klak i dr. 1999b, Rožić i Feil 2000), - započeto je publiciranje uporabnih podataka polja repera u posebnim publikacijama u izdanju Državne geodetske uprave (Klak i dr. 1994a, Klak i dr. 1998c, Rožić i dr. 2001), - projektirana su i izmjerena tri nova vlaka nivelmana visoke točnosti (Koprivnica – Goričan, Virovitica – Terezino polje, Batina – Udvar) sa svrhom povezivanja nivelmanskih mreža geometrijskog nivelmana I. reda između Republike Mađarske i Republike Hrvatske (Klak i dr. 1995b, Klak i dr. 1997b, Klak i dr. 2000), - definiran je geopotencijalni i normalni sustav visina Republike Hrvatske te je obavljeno povezivanje visinskog sustava Republike Hrvatske s Ujedinjenom europskom nivelmanskom mrežom – "United European Levelling Network – UELN" (Klak i dr. 1997, Klak i dr. 1997c, Klak i dr. 1998, Feil i Rožić 2000), - podnesena su izvješća o stanju radova generalnog geometrijskog nivelmana na teritoriju Republike Hrvatske na EUREF Simpozijima (Feil i dr. 1999, Feil i dr. 1999a, Rožić i dr. 2000), - izrađen je prijedlog za uvođenje u službenu uporabu novog visinskog datuma HRVD71 - Hrvatski visinski datum 1971 i visinskog sustava Republike Hrvatske HRVRS71 - Hrvatski visinski referentni sustav 1971 (Feil i Rožić 2000a) koji je ocijenjen od strane međunarodnih savjetnika (Brockman i dr. 2001), - izrađena je Studija o obnovi i održavanju visinskog sustava Republike Hrvatske s analizom rezultata obavljenih radova u razdoblju 1992.-2001. godine i prijedlozima neophodnih radova u budućem razdoblju (Feil i Rožić 2001). Jedna od važnih i prethodno navedenih cjelina je računska obrada i izjednačenje nivelmanskih mjerenja sa svrhom određivanja nadmorskih visina repera. Sastavni dio te obrade je i određivanje kriterija ocjene točnosti. Obzirom da je obrada obavljena za nivelmanske vlakove na cjelokupnom teritoriju Republike Hrvatske dobiveni su konkretni pokazatelji točnosti nivelmanskih mjerenja i visinske točnosti repera. - 26 - 2. IZJEDNAČENJE NIVELMANSKIH MREŽA GEOMETRIJSKOG NIVELMANA Računska obrada nivelmanskih mjerenja, odnosno izjednačenje vlakova i mreža geometrijskog nivelmana na teritoriju Republike Hrvatske, obavljeno je postupno i kontinuirano u razdoblju od 1994. do 2000. godine. Pratilo je obavljanje terenske revizije polja repera, a temeljilo se na rezultatima te revizije i dostupnoj arhivskoj dokumentaciji, primarno arhiva Državne geodetske uprave Republike Hrvatske i sekundarno arhiva nekoliko geodetskih tvrtki: Zavod za fotogrametriju d.d. iz Zagreba, Geodetski zavod d.d. iz Splita i Geodetski zavod d.d. iz Osijeka. Nivelmanske mreže su računski jednoobrazno obrađene i izjednačene sukladno hijerarhijskom načelu, tj. oslanjanjem nižih redova geometrijskog nivelmana na više redove. Kao osnova za uvrštenje mreža nižih redova (PN, GN, TNPT i TN) usvojen je novi visinski datum Republike Hrvatske i mreža IINVT kao temeljna državna nivelmanska mreža, sl. 1. 14 FR3053 Varaždin 15 16 FR3020 Zagreb III 1 BP82 Rovinj 12 5 FR1029 BV Brajkovići 2 MCXVII Bakar 11 9 I 10 C46 Senj 21 IV CP695 Kostajnica DCCLIII Virovitica A437 Novska 20 37 VIII C650 Okučani 44 41 18 BV11530 Daruvar 19 O362 Batina 17 C143 Pčelić 42 K274 43 Našice 38 FR3063 Strizivojna 22 MCCI Ž.Lokva CP317 Osijek 48 REPUBLIKA HRVATSKA II. NIVELMAN VISOKE TOČNOSTI 23 26 V 0 10 20 30 40 50 km Tumač znakova: 25 C162 Šibenik 31 3 čvorni reper VI BV14530 mareograf nivelmanski vlak MCCC Split PN167 30 br. nivel. vlaka XIV 35 C346 Opuzen 63 Geodetski Fakultet Sveučilišta u Zagrebu XV FR1098 XVI C620 Dubrovnik 4 A496 62 60 Slika 1. Nivelmanska mreža IINVT na teritoriju Republike Hrvatske. Izjednačenja mreža su obavljena primjenom funkcijskog modela posrednih regularnih nekoreliranih mjerenja i metode najmanjih kvadrata. Težine mjerenja su određene na uobičajeni način u geometrijskom nivelmanu, tj. recipročno duljinama nivelmanskih vlakova. Podaci mjerenja, nakon prevođenja iz analognog u digitalni oblik, sadržani su i pohranjeni u računalnim datotekama programskog sustava LOTUS 123, dok su izjednačenja obavljena primjenom programskog sustava NIVEL (Rožić 1992). Nivelmanske mreže i vlakovi računski su obrađeni i izjednačeni zasebno po pojedinim nivelmanskim poligonima IINVT, sl. 1. Na taj je način obrada podataka razdijeljena na nekoliko faza. Rezultati obrade su slijedno publicirani u nizu elaborata Geodetskog fakulteta Sveučilišta u Zagrebu. Terenska revizija, računska obrada i izjednačenje obavljeni su, prema vremenskom tijeku izvedbe radova, u sljedećim fazama: - II. nivelmanski poligon IINVT - 1994. godine, - I. nivelmanski poligon IINVT - 1995. godine, - III. nivelmanski poligon IINVT - 1995. godine, - VIII. nivelmanski poligon IINVT - 1996. godine, - IV. nivelmanski poligon IINVT - prvi dio - 1996. godine, - VI., XIV., XV. i XVI. nivelmanski poligon IINVT - 1997. godine, - V. nivelmanski poligon IINVT - 1998. godine, - IV. nivelmanski poligon IINVT - drugi dio - 1998. godine, - 27 - - III. i VIII. nivelmanski poligon IINVT - dopune - 1999. godine, - VIII. nivelmanski poligon IINVT - dopuna - 1999. godine, - IX. nivelmanski poligon IINVT - 1999. godine, - XII nivelmanski poligon IINVT - 1999. godine, - VII. i XI. nivelmanski poligon IINVT i otočke nivelmanske mreže - 2000. godine. Svakoj od prethodno navedenih faza odgovara i zaseban elaborat Geodetskog fakulteta (Klak i dr. 1994, Klak i dr. 1995., Klak i dr. 1995a, Klak i dr. 1996, Klak i dr. 1996a, Klak i dr. 1997a, Klak i dr. 1998a, Klak i dr. 1998b, Rožić i dr. 1999, Klak i dr. 1999, Klak i dr. 1999a, Klak i dr. 1999b, Rožić i Feil 2000) u kojem se nalaze navedeni svi detalji računske obrade i izjednačenja, odnosno njihovi rezultati. Važno je naglasiti da su izjednačenja nivelmanskih mreža nižih redova provedena bez potrebe obavljanja dopunskih terenskih mjerenja, a u svrhu njihovog povezivanja s mrežom IINVT kao okosnicom. Naime, geometrijske konfiguracije mreža Austrijskog preciznog nivelmana i INVT ne podudaraju se s geometrijskom konfiguracijom mreže IINVT (Rožić 2001), ali je obzirom na primjerenu razinu njihove međusobne isprepletenosti postojala dobra osnova za povezivanje i bez dopunskih mjerenja. Također, usvajanjem mreže IINVT za okosnicu visinskog sustava, svi su vlakovi INVT u izjednačenja uvršteni kao vlakovi preciznog nivelmana. Također, neophodno je upozoriti i na činjenicu da je u sklopu izjednačenja obrađen opažački materijal koji pripada različitim vremenskim epohama. Naime, zajednički su obrađeni podaci mjerenja koji se odnose na dulje vremensko razdoblje izmjere. Okosnica visinskog sustava je najmlađa i najkvalitetnija visinska mreža (IINVT), dok je veći dio radova nivelmana nižih redova točnosti stariji od nje i do 25 godina. Zato su u rezultatima izjednačenja sadržani i utjecaji recentnih pomaka Zemljine kore, regionalni visinski pomaci izazvani geodinamičkim silama i pomaci repera izazvani nestabilnošću njihovih mikrolokacija. 3. OCJENA TOČNOSTI GEOMETRIJSKOG NIVELMANA Točnost radova geometrijskog nivelmana na cjelokupnom teritoriju Republike Hrvatske daju jednoobrazno određeni kriteriji točnosti "a posteriori", tj. referentne vjerojatne pogreške mjerenja i vjerojatne pogreške visina čvornih repera određene na temelju izjednačenja nivelmanskih mreža. Po pojedinim redovima nivelmana i nivelmanskim poligonima IINVT, ovi su podaci sadržani u već citiranim elaboratima Geodetskog fakulteta (Klak i dr. 1994, Klak i dr. 1995., Klak i dr. 1995a, Klak i dr. 1996, Klak i dr. 1996a, Klak i dr. 1997a, Klak i dr. 1998a, Klak i dr. 1998b, Rožić i dr. 1999, Klak i dr. 1999, Klak i dr. 1999a, Klak i dr. 1999b, Rožić i Feil 2000). Osim izjednačenja temeljne nivelmanske mreže, tj. mreže IINVT (Rožić 1995), obavljeno je ukupno 127 izjednačenja mreža geometrijskih nivelmana nižih redova točnosti, različite razine složenosti u pogledu broja mjerenja i nepoznanica. Po pojedinim redovima obavljeno je izjednačenje: - 16 mreža preciznih nivelmana, - 58 mreža gradskih nivelmana, - 19 mreža tehničkih nivelmana povećane točnosti, - 34 mreže tehničkih nivelmana. U slučaju izrazito velikih mreža, posebno gradskih nivelmana, npr. Zagreba, Rijeke, Splita, Osijeka, odnosno nekih tehničkih nivelmana, izjednačenja su obavljena u nekoliko dijelova i to ili razdvajanjem mreža na glavnu i sporedne mreže ili razdvajanjem mreža na nekoliko neovisnih dijelova definiranih sukladno njihovim odnosom prema vlakovima višeg reda. U objedinjenom obliku kriteriji točnosti "a posteriori" navedeni su u tablici 1, raščlanjeni po pojedinim nivelmanskim poligonima IINVT i pojedinim redovima nivelmana. U tablicu su uvrštene referentne vjerojatne pogreške mjerenja uo i vjerojatne pogreške visina čvornih repera uH. Navedene su uvijek po dvije vjerojatne pogreške visina čvornih repera. Vjerojatna pogreška visine čvornog repera koja je poprimila najniži iznos (min.- mH) i vjerojatna pogreška visine čvornog repera koja je poprimila najviši iznos (max.- mH). Reperi na koje se odnose ove vjerojatne pogreške imaju najvišu, odnosno najnižu visinsku točnost. Stoga, ove su vjerojatne pogreške dobri pokazatelji točnosti visina svih drugih čvornih repera obuhvaćenih izjednačenjima. Tablica 1. Ocjena točnosti mjerenja i visina čvornih repera (vjerojatne pogreške). IINVT POLIG. uo mm / km I. ± 0,79 PN min.uH max.uH mm ± 0,33 mm ±11,77 uo mm / km GN min.uH max.uH mm mm uo TNPT min.uH max.uH mm mm / km mm uo mm / km TN min.uH max.uH mm mm ± 1,86 ± 1,41 ± 7,09 ± 2,92 ± 0,26 ± 5,21 ± 1,87 ± 3,08 ± 7,77 II. ± 4,59 ± 6,04 ±35,15 ± 1,25 ± 0,23 ± 2,16 ± 3,20 ± 2,43 ± 8,53 III. ± 2,56 ± 1,61 ±10,01 ± 3,25 ± 0,47 ± 4,63 ± 3,97 ± 3,73 ±14,25 - 28 - uo mm / km min.uH max.uH mm mm ± 3,89 ± 2,49 ± 8,72 ± 6,09 ± 1,21 ±14,31 IV. ± 2,28 ± 3,67 ±10,23 ± 2,10 ± 1,03 ± 2,07 V. ± 2,14 ± 2,44 ± 9,20 ± 2,31 ± 0,50 ± 2,37 VI. ± 2,03 ± 1,14 ± 6,06 ± 3,03 ± 0,31 ± 3,86 ± 6,55 ±12,09 ±12,09 VII. VIII. ± 2,47 ± 2,29 ± 9,14 ± 2,75 ± 0,55 ± 4,11 IX. ± 1,15 ± 1,24 ± 9,59 ± 4,84 ± 0,57 ± 4,73 XI. XII. XIV. ± 1,15 ± 1,65 ± 1,24 ± 4,51 ± 9,59 ± 4,77 XV. OTOCI ± 3,33 ± 1,76 ± 5,10 ± 0,51 ± 7,17 ± 1,22 ± 1,33 ± 3,35 ±25,92 ± 6,73 ± 6,59 ±16,53 ± 8,18 ± 0,89 ±19,20 ± 3,57 ± 3,48 ± 6,50 ± 5,60 ± 2,47 ±11,29 ± 2,27 ± 5,41 ± 5,52 ± 6,95 ± 4,10 ± 7,83 ± 3,33 ± 4,48 ± 7,51 ± 8,05 ± 4,62 ±23,67 ± 3,96 ± 2,99 ±12,03 ± 1,47 ± 5,55 ± 6,35 ±11,85 ±16,41 ±27,93 ± 3,41 ± 1,08 ± 5,98 Na temelju podataka tablice 1 mogu se odrediti reprezentativne vrijednosti kriterija točnosti "a posteriori" koje se odnose na pojedine redove geometrijskih nivelmana za cjelokupan teritorij Republike Hrvatske. Tako je za nivelmansku mrežu IINVT referentna vjerojatna pogreška mjerenja (1) u o = ±0.79 mm / km , i vjerojatne pogreške visine čvornih repera mreže s najvišom (min.) i najnižom (max.) visinskom točnošću: (2) min. u H = ±0.33mm, max. (3) u H = ±11.77 mm. Za mreže preciznog nivelmana (PN) reprezentativna vrijednost referentne vjerojatne pogreške mjerenja jest (4) u o = ±2.53mm / km , i vjerojatne pogreške visina čvornih repera mreže: (5) min. u H = ±1.14mm, (6) max. u H = ±35.15mm. Za mreže gradskih nivelmana (GN) reprezentativna vrijednost referentne vjerojatne pogreške mjerenja jest (7) u o = ±2.70 mm / km , i vjerojatne pogreške visina čvornih repera mreže: (8) min. u H = ±0.23mm, max. (9) u H = ±7.17 mm. Za mreže tehničkih nivelmana povećane točnosti (TNPT) reprezentativna vrijednost referentne vjerojatne pogreške mjerenja jest (10) u o = ±3.42 mm / km , i vjerojatne pogreške visina čvornih repera mreže: (11) min. u H = ±2.43mm, max. (12) u H = ±14.25mm. Konačno, za mreže tehničkih nivelmana (TN) reprezentativna vrijednost referentne vjerojatne pogreške mjerenja jest (13) u o = ±6.61mm / km , i vjerojatne pogreške visina čvornih repera mreže (14) min. u H = ±0.89mm, (15) max. u H = ±27.93mm. 4. ANALIZA OCJENE TOČNOSTI I ZAKLJUČCI Na temelju podataka ocjene točnosti navedenih u prethodnom poglavlju može se donijeti nekoliko zaključaka. Prije svega, temeljem izraza (1), (4), (7), (10) i (13) može se zaključiti da na ukupnom teritoriju Republike Hrvatske postignute točnosti mjerenja u svim redovima nivelmana uglavnom zadovoljavaju unaprijed postavljene kriterije točnosti, utvrđene prijedlogom Pravilnika o radovima geometrijskog nivelmana (Klak i dr. 1993) i da se točnost mjerenja logično smanjuje od viših prema nižim redovima. U prijedlogu Pravilnika su određene dopuštene vrijednosti referentnih vjerojatnih pogrešaka mjerenja za pojedine redove geometrijskog nivelmana i to: - 29 - - nivelman visoke točnosti, uo = ±1mm / km , - precizni i gradski nivelman, uo = ±2mm / km , - tehnički nivelman povećane točnosti, uo = ±5mm / km , - tehnički nivelman, uo = ±8mm / km . Jedine, relativno male, iznimke su precizni i gradski nivelmani kod kojih je točnost mjerenja neznatno niža nego je kriterijima točnosti dopušteno. Ove razlike su prihvatljivog reda veličine, posebno obzirom na različite vremenske epohe kojima pripadaju podaci IINVT u odnosu na epohe preciznog i gradskih nivelmana. Ipak, podaci ocjene točnosti mjerenja navedeni u tablici 1, pokazuju da na teritoriju Republike Hrvatske nije postignuta, u okviru pojedinih redova geometrijskog nivelmana, u potpunosti homogena točnost. Razvidno je da je na pojedinim dijelovima njenog teritorija, tj. u pojedinim poligonima IINVT, točnost mjerenja u okviru istih redova nivelmana različita i ponekad izrazitije niža nego je to dopušteno. Izvori ove nehomogenosti primarno su vezani uz kvalitetu izmjere, postupke pri mjerenju, instrumentarij i druge uvjete. Sekundarno, posljedica su različitih vremenskih epoha kojima pripadaju pojedini redovi nivelmana, a izjednačeni su hijerarhijskim uklapanjem mreža nižih redova u fiksni (zadani) okvir mreža viših redova. Visinska točnost repera, sudeći na temelju točnosti visina čvornih repera, može se smatrati zadovoljavajućom i logičnom u odnosu na točnost mjerenja. U cjelokupnom preciznom nivelmanu, uzevši u obzir čitav državni teritorij, čvorni reper s najnižom točnošću visine ima vjerojatnu pogrešku od ± 35 mm, u gradskom i tehničkom nivelmanu povećane točnosti od ± 7mm, odnosno od ± 14 mm te u tehničkom nivelmanu od ± 28mm. Veliki broj čvornih repera ima i znatno višu točnost visina, što je zorno vidljivo u podacima tablice 1. Pri tom, treba uzeti u obzir da su točnosti visina čvornih repera dijelom uvjetovane i načinom izjednačenja mreža, tj. pretpostavkom bespogrešnosti repera viših redova nivelmana. Zanimljiv je i odnos točnosti visina repera slijedno po različitim redovima, od najvišeg prema najnižem. Najniža točnost visina repera pretežno se javlja u preciznom nivelmanu, dok je u ostalim redovima nivelmana viša nego u preciznom nivelmanu. U tim nivelmanima, od gradskih do tehničkih, točnost se suvislo smanjuje s redom nivelmana. Ova nelogičnost u razdiobi visinske točnosti repera, jer visinska točnost bi se od nivelmana visoke točnosti trebala postupno smanjivati prema tehničkom nivelmanu, također je vjerojatno posljedica različitih vremenskih epoha kojima pripada mreža IINVT i mreže popunjavajućih nivelmana. Postignute točnosti mjerenja i visinske točnosti repera, do određene su mjere i iznenađujuće. Naime, uzevši u obzir činjenicu da je na hijerarhijskom načelu izjednačen opažački materijal prikupljen izmjerom iz dugog vremenskog razdoblja i bitno različitih vremenskih epoha, mjeren različitim instrumentarijem, postupcima i priborom te najvećim dijelom prikupljen u vrlo skromnim materijalnotehničkim uvjetima (razdoblje od 1945. do 1963. godine), dobiven je relativno zadovoljavajući rezultat. Bez obzira na određene nedostatke koje radovi geometrijskog nivelmana svakako sadrže, još uvijek imaju primjerenu uporabnu vrijednost, posebno za praktične potrebe. Uostalom, u ovom trenutku Republika Hrvatska ne raspolaže kvalitetnijim nivelmanskim radovima koje bi mogla uvesti u službenu uporabu, a novi sustavni radovi na obnovi polja repera i osuvremenjivanju državnih mreža geometrijskog nivelmana još uvijek nisu započeti. LITERATURA Brockmann, E., Harsson, B.G., Ihde, J. (2001): Geodetic Reference System of the Republic of Croatia, Consultants Final Report on Horizontal and Vertical Datum Definition, Map projection and Basic Networks, Tehnical Report, June 2001. Feil, L., Klak, S., Rožić, N., Gojčeta, B. (1999): National report of the Republic of Croatia on the high system, Mitteilungen des Bundesamtes für Kartographie und Geodäsie, Band 6, EUREF Publication No. 7/I, Frankfurt am Main, 142-148. Feil, L., Klak, S., Rožić, N., Gojčeta, B. (1999): National report of the Republic of Croatia on the Height System, Veröffentlichungen der Bayerischen Kommission für die Internationale Erdmessung der Bayerischen Akademie der Wissenschaften, Report on the Symposium of the IAG Subcommission for Europe (EUREF) held in Prague, 2-5 June 1999, München, Heft Nr. 60, 146149. Feil, L., Rožić, N. (2000): UELN geopotencijalni i normalni visinski sustav Republike Hrvatske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Feil, L., Rožić, N. (2000a): Prijedlog službenog visinskog datuma Republike Hrvatske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Feil, L., Rožić, N. (2001): Studija o obnovi i održavanju visinskog sustava Republike Hrvatske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. - 30 - Klak, S., Feil, L., Rožić, N. (1992): Studija o sređivanju geometrijskog nivelmana na području Republike Hrvatske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1993): Pravilnik o radovima geometrijskog nivelmana – prijedlog, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1994): Izjednačenje nivelmanskih mreža svih redova u II. nivelmanskom poligonu II.NVT, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1994a): Podaci o reperima - knjiga 1, Državna geodetska uprava Republike Hrvatske, Zagreb, 1994. Klak, S., Feil, L., Rožić, N. (1995): Izjednačenje nivelmanskih mreža svih redova u I. nivelmanskom poligonu II.NVT, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1995a): Izjednačenje nivelmanskih mreža svih redova u III. nivelmanskom poligonu II.NVT, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1995b): Povezivanje nivelmana visoke točnosti Republike Hrvatske, Republike Slovenije i Republike Mađarske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1996): Izjednačenje nivelmanskih mreža svih redova u VIII. nivelmanskom poligonu II.NVT, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1996a): Izjednačenje nivelmanskih mreža svih redova u IV. nivelmanskom poligonu II.NVT - prvi dio, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1997): Ispitivanje mogućnosti određivanja geopotencijalnih visina, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1997a): Izjednačenje nivelmanskih mreža svih redova u VI., XIV., XV. i XVI. nivelmanskom poligonu II.NVT, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1997b): Povezivanje nivelmana visoke točnosti Republike Hrvatske i Republike Mađarske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1997c): Precise levelling data of the Republic of Croatia for the United European Levelling Network, Državna geodetska uprava Republike Hrvatske, Zagreb. Klak, S., Feil, L., Rožić, N. (1998): Connecting of levelling of high accuracy between the Republic Hungary and the Republic of Croatia in geopotential height system. Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1998a): Izjednačenje nivelmanskih mreža svih redova u V. nivelmanskom poligonu II.NVT, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1998b): Izjednačenje nivelmanskih mreža svih redova u IV. nivelmanskom poligonu II.NVT - drugi dio, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1998c): Podaci o reperima - knjiga 2, Državna geodetska uprava Republike Hrvatske, Zagreb. Klak, S., Feil, L., Rožić, N. (1999): Izjednačenje nivelmanskih mreža svih redova u VIII. nivelmanskom poligonu II.NVT – dopuna, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1999a): Izjednačenje nivelmanskih mreža svih redova u IX. nivelmanskom poligonu II.NVT, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (1999b): Izjednačenje nivelmanskih mreža svih redova u XII. nivelmanskom poligonu II.NVT, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Klak, S., Feil, L., Rožić, N. (2000): Povezivanje nivelmana visoke točnosti Republike Hrvatske i Republike Mađarske - drugi dio, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Rožić, N. (1992): Kompjutorski program za izjednačenje nivelmanskih mreža – NIVEL, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb, 1992. Rožić N. (1995): Ispitivanje slučajnih i sistematskih pogrešaka u geometrijskom nivelmanu, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb, doktorska disertacija, Zagreb. Rožić, N., Feil, L. (2000): Izjednačenje nivelmanskih mreža svih redova u VII. i XI. nivelmanskom poligonu II.NVT i izjednačenje otočkih nivelmanskih mreža, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Rožić, N., Feil, L., Pavičić, S. (2000): Review of Activities on Levelling Works in the Republic of Croatia 1999-2000, Veröffentlichungen der Bayerischen Kommission für die Internationale Erdmessung der Bayerischen Akademie der Wissenschaften, Report on the Symposium of the IAG Subcommission for Europe (EUREF) held in Tromsø, 22-24 June 2000, München, Heft Nr. 61, 362-365. Rožić, N., Feil, L., Pavičić, S. (2001): Podaci o reperima - knjiga 3, Državna geodetska uprava Republike Hrvatske, Zagreb. Rožić, N., Klak, S., Feil L. (1999): Izjednačenje nivelmanskih mreža svih redova u III. i VIII. nivelmanskom poligonu II.NVT – dopune, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb. Rožić, N. (2001): Fundamental levelling networks and height datums at the territory of the Republic of Croatia, Acta Geodaetica et Geophysica Hungarica, Budapest, Vol. 36 (2), 231-243. - 31 - - 32 - STATUS OF THE CROATIAN FIRST ORDER GRAVITY NETWORK* Željko Hećimović, Nevio Rožić, Tomislav Bašić, Danko Markovinović ABSTRACT Since Croatian Geodetic Institute (CGI) started to work in December 2001 preliminary work regarding measurements of the Croatian First Order Gravity Network has been carried out. The network will be connected to the Croatian Zero Order Gravity Network. For measurements of the Croatian First Order Gravity Network two Scintrex CG-3M gravimeters are prepared: HGI-1 and HGI-2. Their behavior and capabilities are systematically analyzed: drift, temperature compensation, tilt sensor zero adjustment, tilt sensor sensitivity adjustment, tilt sensor cross coupling, battery check and gravimeter clock drift. In this period drifts of the both gravimeters become more linear, and that is improvement of the main gravimeter characteristic. To analyze structure of a gravimeter signal in detail, stability of the HGI-2 gravimeter was analyzed using wavelet multiresolution technique. To verify gravimeters in the fieldwork, test measurements were done. Design of the test gravity network contains two absolute gravimetric points. That is giving opportunity for reliable verification of the gravimeters. Gravimeters analysis is showing that they can be used in measurements of the Croatian First Order Gravity Network. 1. INTRODUCTION A project of establishing new Croatian First Order Gravity Network is one of the projects that Croatian State Geodetic Administration (SGA) implemented in a five years plan "State Survey and Real Estate Cadastre" that is supported by Croatian government. All gravimetric works in Croatia are going to be connected to the Zero Order Gravity Network (see Fig. 1). It was established in the projects: Connection of the Republic of Croatia to international absolute gravity network and UNIfication of GRAvity systems in Central Europe (UNIGRACE). Absolute measurements were done by Bundesamt für Kartographie und Geodäsie (BKG) from Frankfurt am Main (Germany) and Ecole et Observatorie des Sciences de la Terre (EOST) from Strasbourg (France). Zero Order Gravity Network includes six absolute gravity points: Zagreb - Puntijarka, Zagreb - Maksimir, Osijek, Pula, Makarska and Dubrovnik (Čolić et al., 1997; Čolić et al., 2000; Medak et al., 2001a; Medak et al., 2001b; Marjanović, 2002). The new Croatian First Order Gravity Network will be connected to the Croatian Zero Order Gravity Network and data of absolute points are checked and systemized. Revision of the Croatian part of former Yugoslavia gravity network, and proposal for new Croatian First Order Gravity network was made by the Faculty of Geodesy University of Zagreb (Bašić et al., 2001, Markovinović, 2001). The proposal includes design of the new gravity network and national calibration line (see Fig. 1 and 2). The New Croatian First Order Gravity Network includes 36 points on the land, and 15 points should be placed on the islands. Croatian calibration line consists of 10 points in north-south direction (see Fig. 2). Three points are absolute gravimetric points. The differences in latitude of the first and the last point is ≈ 2° 32' (≈ 270 km) (Markovinović and Rezo, 2002). Croatian Geodetic Institute (CGI) is a new institution. It started to work in December 2001. In that time Zero Order Gravity Network was already defined and design of the First Order Gravity Network was determined. 2. GRAVIMETERS PREPARATION FOR MEASUREMENT OF THE I. ORDER GRAVITY NETWORK After establishment and foundation of the CGI two relative Scintrex CG-3M gravimeters (HGI-1 and HGI-2) were received from SGA. They will be used in measurement of the First Order Gravity Network. Before using the relative gravimeters in measurements of state gravity networks they should be proofed and analyzed. They should satisfy measurement criteria. Considering the problem, extensive work has been done. It includes: gravimeters initial verifying, systematic analysis of gravimeters main Predstavljeno na EUREF2003 simpoziju (Symposium of the IAG Subcommission for Europe – EUREF) održanom u Toledu, Španjolska, 3.-8.6.2003. godine. Objavljeno u zborniku radova Simpozija (Hećimović, Ž., Rožić, N., Bašić, T., Markovinović, D.: Status of the Croatian First Order Gravity Network. Mitteilungen des Bundesamtes für Kartographie und Geodäsie, Band 33, EUREF Publication No. 13, Frankfurt am Main, 2004, 306-310). * - 33 - characteristics, analysis of measurements system stability and drift, gravimeter testing on the basis of field measurements and calibration. Fig. 1 Croatian Zero (squares) and the First Order Gravity Networks (triangles) Fig. 2 Croatian calibration line 3. GRAVIMETERS INITIAL CHECKING During initial verifying of gravimeters HGI-1 and HGI-2 functionality it was discovered that operating systems in both gravimeters had millennium bug. After contacting the gravimeters manufacturer Scintrex, new operating systems were received and replaced in the both gravimeters. Another delay of using gravimeter HGI-1 was caused by the malfunctioning of temperature sensor. The gravimeter was repaired in Scintrex (Canada). After repairing it, the same gravimeter experienced reading jumps (tare). The analysis of problem showed that the reading jumps were caused by change of a rate of an artificial, man made, micro seismic in the building where measurements were done (Hećimović, 2002), and reading jumps were not caused by malfunctioning of the gravimeter (Hrvatski geodetski institut, 2002a). 4. SYSTEMATIC ANALYSIS OF GRAVIMETERS' MAIN CHARACTERISTICS After solving the initial problems, the gravimeters have been made fully operable. To prepare gravimeters for measurements of the national gravity networks their behavior and capabilities are systematically analyzed. That includes regular checking of: drift, temperature compensation, tilt sensor zero adjustment, tilt sensor sensitivity adjustment, tilt sensor cross coupling, battery check and gravimeter clock drift. Gravimeters are systematically analyzed in the period of about one year. At the beginning of the analysis period, drifts of both gravimeters were parabolic and at the end of analyzing period, drifts became more linear. Drifts unlinearities in both gravimeters (HGI-1 and HGI-2) can be clearly recognized in a longer continuous measurement (see Fig. 3 and 4). Fig. 3. Readings of the gravimeter HGI-2 at the beginning of the analysis period - 34 - Fig. 4. Readings of the gravimeter HGI-2 at the end of the analysis period Parabolic drift of the HGI-1 on the beginning of the analysis period can be clearly recognized in seventeen days continuous measurements (see Fig. 3). Drift of HGI-2 had become more linear with time and at the end of the analysis period it had much better linearity characteristic (see Fig. 4). Parabolic drift of the gravimeter HGI-1 at the beginning of the analysis period can be clearly recognized in two weeks continuous measurements (see Fig. 5). At the end of the analysis period drift of HGI-1 had much better linearity characteristic (see Fig. 6). Fig. 5. Readings of the gravimeter HGI-1 at the beginning of the analysis period Fig. 6. Readings of the gravimeter HGI-1 at the end of the analysis period Drifts are significantly improved in both gravimeters. That is improvements of the main gravimeters characteristic. Other gravimeters characteristics, that are systematically analyzed, are indicating normal behavior of the gravimeters. 5. ANALYSIS OF GRAVIMETER MEASUREMENTS SYSTEM STABILITY Stability of the measurements system is also one of the main gravimeter characteristics. It has long and short time characteristic. Long-term stability of gravimeters HGI-1 and HGI-2 is analyzed using drift changes in the period of about one year (see Fig. 7 and 8). Fig. 7. Drift of HGI-1 Fig. 8. Drift of HGI-2 Drift change of the gravimeter HGI-1 is showing irregular behavior, but the amplitudes are significantly smaller than by the gravimeter HGI-2. Drift of the gravimeter HGI-2 has decreasing trend, but drift changes are significantly bigger than by the HGI-1. Drift changes of the HGI-2 are smaller in the second part of analyzing period, and they are showing long time stabilization of the measurements system of HGI-2. To analyze the short time stability of the measurements system, the signal of the gravimeter HGI2 was analyzed using wavelet multiresolution technique (Hećimović and Markovinović, 2002). Coifman wavelet (Coiflet) of the fifth order from the family of orthogonal wavelet was used. Coifman wavelet is presented on the Fig. 9 and on the Fig. 10 is associated scaling function. Multiresolution was made until the third level (see Fig. 11). - 35 - th Fig. 9. Coifman wavelet of the 5 order Fig. 10. Associated scaling function Fig. 11. Wavelet multiresolution decomposition. Input in wavelet analysis is one-day continuous measurement signal of gravimeter HGI-2 (see Fig. 12). Gravimeter readings are in real time corrected for scaling factor, temperature, "a priori" drift, Earth tides and gravimeter tilt. Fig. 12. One-day continuous readings used in wavelet analysis. Fig. 13 is showing wavelet decomposition of the signal: approximation on the third level (A3) and details on the all three levels (D1, D2 and D3). The approximation is taking trend and the main part of signal energy. It is free of high frequency part. In the approximation A3, the remaining signal of half-day period can be recognized (see Fig. 13). It could be caused by not completely compensated reductions (e.g. Earth tides). Signal disturbances in -5 -2 approximation (A3) are from 10 to 30 minutes long. They are irregular and smaller then 0,010·10 ms . They are most probably caused by longer microseisnmic influences on the measurements. Details are having the characteristic of the noise. With the higher decomposition level, amount of information in detail is lower and the noise has finer structure. The details are giving insight in the short -5 time instabilities of the measurement system. Amplitude of detail D1 is 0,017·10 ms -5 0,015·10 -2 ms -5 and for D3 is 0,009·10 -2 -2 for D2 is ms . The detail D1 has period of about one-epoch of - 36 - measurements (60 seconds), detail D2 has four epochs and detail D3 has little bit less than then epochs. In the table 2 there are the main statistical characteristics of the details given, and on Fig. 14 there are the distributions of the details presented. Fig. 13. Approximation A3 and decomposed details D1, D2 and D3. Table 2: Main statistical characteristics of the details. Fig. 14. Distributions of the details D1, D2 and D3. 6. TEST MEASUREMENTS To check gravimeters in the fieldwork, test measurements were done. Design of the test gravity network (see Fig. 15) contains two absolute gravimetric points (1 Zagreb Maksimir and 2 Zagreb Puntijarka). - 37 - Fig. 15. Gravimetric test network 6 To collect the data that can be used for reliable checking of the instruments, star method in all three combinations is used. -5 -2 After measurements reductions and drift corrections a priori closure of figure is 0,011·10 ms for -5 -2 gravimeter HGI-1 and 0,013·10 ms for gravimeter HGI-2. Network datum is defined with two absolute -5 -2 points. After adjustment, the referent standard deviation is 0,0096·10 ms . The new gravity value of the -5 -2 third point has difference in comparison to old Yugoslav gravity network of 14,8·10 ms . That is the difference between datum defined by two absolute gravity points and the old Yugoslav gravity datum (Hrvatski geodetski institut, 2002b). The old Yugoslav gravity datum, that Croatia was a part of, was determined by using the datum point in Belgrade. 7. GRAVIMETERS CALIBRATION Measurements on the two absolute points, that are also a part of the Croatian calibration line, are -5 -2 used for calibration of gravimeters. Gravity difference between the absolute points is 151·10 ms what is giving opportunity for calibration. Linear calibration coefficient was determined and imported in memory of gravimeter. In that way the gravimeters are in real time scaled considering the Croatian calibration line. 8. CONCLUSIONS Preliminary work for measurements of the Croatian First Order Gravity Network has been done. The analysis of gravimeters HGI-1 and HGI-2 is showing tendency of increasing gravimeter measurements quality and performances. They can be used for measurements of the Croatian national gravity network. All preparations for measurements of the First Order Gravity Network are done. Faculty of Geodesy University of Zagreb will do field measurements. They will start this spring. REFERENCES Bašić T., Markovinović D., Rezo M., Špoljarić D., Hećimović Ž. (2001): Studija stanja i prijedlog nove Osnovne gravimetrijske mreže Republike Hrvatske. Geodetski fakultet Sveučilišta u Zagrebu, Zagreb 2001. Čolić K., Pribičević B., Špoljarić D., Medak D., Markovinović D., Švehla D., Lelas N. (1997): Izvješće o radovima na projektu: Pripajanje Republike Hrvatske u svjetsku apsolutnu gravimetrijsku mrežu. Geodetski fakultet Sveučilišta u Zagrebu, Zagreb 1997. Čolić K., Pribičević B., Medak D., Đapo A., Ivičević V., Lothammer A., Buljan D. (2000): Elaborat o izvršenim radovima na projektu: Priključenje Republike Hrvatske u svjetsku apsolutnu gravimetrijsku mrežu. Geodetski fakultet Sveučilišta u Zagrebu, Zagreb 2000. Hećimović, Ž., D. Markovinović (2002): Stabilnost mjernog sustava Scintrex HGI-2 gravimetra. Zbornik znanstveno - stručnog simpozija Geodetskog fakulteta Sveučilišta u Zagrebu povodom 40. obljetnice samostalnog djelovanja 1962. - 2002., str. 95 - 104, Zagreb 2002. Hećimović (2002): Reading jumps of HGI-1 Scintrex CG-3M gravimeter. Presented in International Gravimetry Summer School. Louvain-la-Neuve (Belgija) 3 - 12 September 2002. - 38 - Hrvatski geodetski institut (2002a): Izvješće o ispitivanju uzroka skokova u očitanjima gravimetra HGI-1. Odjel za osnovne geodetske radove, Zagreb 2002. Hrvatski geodetski institut (2002b): Izvješće o obradi podataka testnih 78 mjerenja Scintrex CG-3M gravimetrima. Odjel za osnovne geodetske radove, Zagreb 2002. Marjanović M. (2002): Gravimetrijski radovi. Državna geodetska uprava, Zagreb 2002. Markovinović D. (2001): Gravimetrijska mreža I. reda i gravimetrijska kalibracijska baza Republike Hrvatske. Magistarski rad. Geodetski fakultet Sveučilišta u Zagrebu, Zagreb 2001. Markovinović D., Rezo M. (2002): Basic Gravimetric Network of the Republic of Croatia. Poster Session. I. Ph.D. Civilexpo, International Ph.D. Conference of Civil Engineering, November 21-22 2002, Budapest, p. 197-199. Medak D., Pribičević B., Đapo A., Lothammer A., Luck B. (2001a): Elaborat o izvršenim radovima na projektu: Priključenje Republike Hrvatske u svjetsku apsolutnu gravimetrijsku mrežu - Druga faza projekta UNIGRACE. Geodetski fakultet Sveučilišta u Zagrebu, Zagreb 2001. Medak, D., B. Pribičević, A. Đapo (2001b): Priključenje Republike Hrvatske u svjetsku apsolutnu gravimetrijsku mrežu - Projekt UNIGRACE. Izvješće o znanstveno-stručnim projektima iz 2000. godine. Državna geodetska uprava, 23-32, Zagreb 2001. - 39 - - 40 - STRATEGY AND SYSTEM OF QUALITY CONTROL OF THE OFFICIAL GEOGRAPHIC DATA PRODUCED BY PRIVATE COMPANIES IN CROATIA* Nevio Rožić ABSTRACT Recognizing specific needs of the Republic of Croatia regarding the official geographic (topographic) data needs in transition period, specific strategy for production of data and quality control system for produced data are defined by responsible government administration bodies and professional institutions. The Strategy yields so called "Croatian model" which is based on interaction and coordination between three main subjects at national level, e.g. State Geodetic Administration (SGA), Croatian Geodetic Institute (CGI) and private companies licensed for carrying out state survey works. Each subject has precise role and responsibility in the process of producing geographical (topographical) data or "geodetic products" specified by SGA product specifications. The products are at disposal to all users from private persons or companies to governmental and non governmental institutions. The above mentioned "Croatian model" is still being developed and implemented with so far good results achieved. Regarding the Croatian Geodetic Institute participation in "model" implementation, the main objectives are establishment and implementation of the Quality Control System which should provide efficient, transparent and professional quality control of specified data and/or geodetic products: topographic (vector) data, topographic maps in the scale of 1:25000 and orthophoto maps in the scale of 1:5000, etc. produced for the Croatian Government by private companies. 1. INTRODUCTION After acquiring the independence and sovereignty at the beginning of the 90-ties there were significant and extensive activities initiated in the Republic of Croatia in the field of geodetic and surveying works, starting and initiating production of geographical (topographical) data and building of a Spatial Data Infrastructure at the national (state) level. The activities included wide range of working fields: reorganization of existing state bodies and institutions competent for carrying out geodetic and surveying work, foundation of new specialized government institution - Croatian Geodetic Institute, creating new and significantly improved laws and ordinance basis, evaluating, readjusting and using the inherited geodetic basis from the former state in new circumstances (fundamental state networks, geodetic datums, cartographic projection, etc.), carrying out new fundamental geodetic works at the state territory, organizing and motivating Croatian private companies to start producing the geodata and specific geodetic products for state needs, etc. Among all activities special importance has been given to the development and renewal of the large program of production of the topographic map series and orthophoto maps simoultaneously with new cadastral surveys including solving complex problems connected with land registry inherited from the former state. Mentioned activities have become very intensive especially after 1995 and they were carried out during the period from 1995 till today in organized and systematic way, in accordance with objective Croatian situation determined by internal and external conditions. The great influence made on the whole process was and still is strongly connected with international and European globalization processes, democratization of the state and state administration, very fast and quite radical general and specific technological changes, restructuring, privatization, transition to the market economy and protection of private ownership, geodetic and surveying heritage from former state, level of organization and efficiency of Croatian administration and other professional institutions, economic and financial potential of the state, etc. In accordance with all conditions which have some influence on the results of above-mentioned activities, their arrangement and organization, Croatia is trying to find its own way by following the international and European positive experiences with necessary tailoring to the specific Croatian situation and with the main intension to make transition period as short, efficient and productive as can be * Predstavljeno na "Cambridge Conference 2003" održanoj u Cambridge-u, Engleska, 20.-25.7.2003. godine. Objavljeno u zborniku radova Konferencije (Rožić, N.: Strategy and System of Quality Control of the Official Geographic Data Produced by Private Companies in Croatia. Conference papers of the Cambridge Conference 2003 "National mapping – shaping the future", Paper 7.3, Ordonance Survey, England, 2003). Dostupno na CD-ROM mediju i Internet stranicama Konferencije www.cambridge conference2003.com - 41 - achieved. As usual, "Croatian model", if one can speak about a model regarding the production of geographical data, maps and some other products, is somewhere in the range between two extreme alternatives, i.e. between the national wide mapping and geographical data producing like obligatory task of the governmental bodies/organizations financed by government with taxpayers money and with the data kept as a state secret and the mapping left completely to the market and private enterprises where the government is only one of the potential customers in the market in accordance with the present and near future state needs. Regarding setting and general frame of "Croatian model", three basic "players" or groups of "players" are in the game: State Geodetic Administration (SGA), Croatian Geodetic Institute (CGI) and private companies registered and licensed to work in the field of the state survey and real estate cadastre. Their competences and responsibilities, functions, fields of work and roles in joint and coordinated production of national geographic data and building of National Spatial Data Infrastructure are defined and determined precisely enough starting from visions and strategies, including planning, financing and organizing over to the execution and finally fulfillment of the user needs. 2. GENERAL BASIS FOR OFFICIAL GEOGRAPHIC DATA PRODUCTION AND QC Present situation in Croatia regarding general setting at the state level in respect with the official geographic data production and quality control is a significant consequence of the new Law of State Survey and Real Estate Cadastre (Official Newspaper 1999) proposed by the SGA and delivered by Croatian Parliament and started to be implemented from the beginning of 1999. 2.1. STATE GEODETIC ADMINISTRATION In accordance with the Law, the SGA being the basic state body responsible for geodetic and surveying works and spatial data infrastructure at the whole state territory is reorganized, or is better to say organized to be a unique and integral administration encompassing the Central Office in Zagreb and all branch offices adequately distributed throughout the entire territory of Croatia (at this moment SGA consists of about 110 branch offices with approximately 1100 employees). It has the authorities to do all administrative, normative, regulative and standardizing jobs in connection with the state survey and real estate cadastre. There has been a great change made in comparison with the previous period, i.e. before 1999. Namely, in the previous period the branch offices of SGA, i.e. former local cadastral offices, used to be under the competence of local self-government units. In this respect, SGA is constituted pursuant to the new Law as a unique and a coherent government body. It should also be emphasized that SGA branch offices are still primarily related to the cadastral activities while SGA central office in Zagreb is covering wide range of all other topics. In particular, especially great importance is given to the preparing of laws, bylaws and ordonance basis, technical geodetic and surveying standards, preparation of the annual or several years state survey and real estate programs and their realization and implementation. In that respect, the internal structure and organization of SGA central office is adjusted to function efficiently. It should also be emphasized that SGA is not directly involved in production of geographic (topographic) data and products based on these data internally. Production is planned and financed by SGA but outsourced to the private sector, i.e. private companies licensed for production in accordance with SGA product specifications. Planning and financing is based on adequate one year or several years programs, at the present moment Program of State Survey and Real Estate Cadastre for the period 2001-2005 is just being carried out, proposed by SGA and approved by Croatian Parliament (Official newspaper 2001). The example of some very important products in the field of responsibility of SGA, according to the SGA official catalogue of products (State Geodetic Administration 2001), can be presented as follows: - Aerial photographs in the scale of 1:20000 from systematic cyclical photo shooting of the state territory - Orthophoto maps in the scale of 1:5000 - Croatian base maps in the scale of 1:5000 - Topographic maps in the scales of 1:25000, 1:100000, 1:200000, etc. - Cadastral maps in the scales 1:1000, 1:2000, 1:2880, etc. 2.2. CROATIAN GEODETIC INSTITUTE In addition to all structural, functional and other changes regarding SGA, one of very important changes in terms of modernizing and reorganizing geodetic and surveying activities in Croatia is the foundation of a separate and specialized public institution intended for performing scientific and highly - 42 - professional geodetic works at the state level. This new institution, founded by the same Law, is Croatian Geodetic Institute. Founder of the CGI is the Republic of Croatia and rights of founder are implemented by the Government. In the Republic of Croatia there has never been such an institution. During the long period of time, from the end of II. World War till the moment of CGI foundation, the practical realization of high professional geodetic and surveying works (for example: state control networks of higher orders, map series in the scale 1:25000, etc.) had been always under the competence of Military and Geographic Institutes of the former states. As Law became operative, during 2000. concrete activities were initiated in connection with the formation and establishment of CGI and have been continuously performed ever since. With foundation of the CGI for the first time in the Republic of Croatia, administrative, normative and regulative jobs in the field of geodesy at the state level are started to be separated from professional jobs. CGI shoud be responsible for professional jobs and SGA should take care of the administrative and normative jobs. CGI is formed as a specialized institution but without the rights to be profitable or to compete with private companies at market. The work of CGI is regulated by the Law of State Survey and Real Estate Cadastre, by the Law of Institutions and other positive laws and regulations of the Republic of Croatia. Within its activity CGI should perform the following jobs: - Conduct fundamental geodetic works - Constitute topographic, cartographic and land registry databases - Conduct topographic survey - Constitute and keep geographic names register - Conduct survey and marking of state border - Conduct development and research projects - Standardization of geodetic works and procedures. Internal constitution of the CGI is based on the planned type and volume of geodetic works that it should perform. The internal constitution is defined with four departments: - Department for mutual jobs - Department for fundamental geodetic works - Department for topographic survey and supervising - Department for geoinformation systems and databases. Apart from the fact that CGI is constituted as an independent and specialized professional institution for performing mentioned specific works, CGI is strongly connected with SGA and obliged to jointly perform geodetic works and activities in accordance with the annual working programs harmonized with the working programs of SGA at state level. In explained setting, accordingly to the relations established between SGA and CGI, one very important function is directed to the CGI. That is quality control function with the main purpose to provide and assure the quality and homogeneity of geodetic products, i.e. official geographic (topographic) data produced for SGA (Croatian government) by private companies. It should be pointed out that providing and approving the quality of the official geographic data produced for the state has never been solved at the territory of Croatia in that way. Additionally, it must be said that CGI's work on providing and controlling the quality has started to be realized simultaneously with the foundation and building of CGI's overall infrastructure and capacities for undertaking that work (equipment, education and specialization of personnel, defining of procedures and methods, etc.). CGI's quality control function is strongly related and harmonized with the realization of the Program of State Survey and Real Estate Cadastre for the period 2001-2005 (Official newspaper 2001). Further more, in the same time the whole activity is strongly overlapping with quite recent activities of implementation and realization of the important GI project prepared and organized in the frame of technical and financial help given to the Republic Croatia by the Kingdom of Norway - CroatianNorwegian GeoInformation Project. 2.3. CROATIAN PRIVATE COMPANIES In accordance with all transition changes that have happened in Croatia from 1990 untill today, all geodetic and surveying companies have become private companies (private ownership). Some of them which existed in period before 1990 were privatized but at the same time some companies were initially founded after 1990.It should be said that several bigger companies with significant professional potential and infrastructure for production of geographic (topographic) data have remarkable tradition and experience because they were founded immediately after II. World War and they had been developed during the period of almost 50 years. It is interesting that these companies are not exclusively concentrated in Zagreb (capitol of the Republic of Croatia) but they are dispersed to the most bigger Croatian cities spread over the country, for example: Split, Rijeka, Osijek, etc. Several bigger companies were newly founded as well, after 1990, on the basis of the possibilities and conditions to develop private enterprises. Some of them were founded by Croatian experts with work experience from abroad and they were developed in quite fast and efficient way. It is important to point out that all those companies, - 43 - privatized old ones and new ones, have very solid and recent technological infrastructure and level of technical knowledge with experienced people involved in the production processes. They are fully capable to produce specific products and geographical data for government needs in accordance with SGA product specifications. In accordance with their development and continuous technological modernization during last 10 years they gave a strong contribution to upgrading and improving of specialized geodetic works at state level on the basis of appropriate coordination and collaboration with SGA. At this moment, for example production infrastructure for producing of Topographic maps in the scale of 1:25000 has already been developed and usable in at least 6 private companies and all these companies were actively included in their production during the last 6 years. Those companies are competitors in public procurement procedures organized by SGA, regarding possibility of choosing the best and most efficient (cost/benefit) production. Simultaneously with the mentioned production for government needs, the private companies are completely free to produce other kinds of data or products for other investors in accordance to their needs and apart from predefined product specifications maid by SGA. Apart from those bigger and "infrastructurally developed" private companies there are at the state level also several hundreds (more than 400) of quite small private companies licensed to work in the field of state survey and real estate cadastre. But all those companies (some of them are functioning only with one or mybe two experts), founded practically after 1990, are related first of all to cadastre and real state work or other specific kinds of work. Their production infrastructure, knowledge and production potentials are not appropriate for the production of, for example, topographic maps, etc. 3. STRATEGY As already mentioned in the introduction, two extreme alternatives (models) are possible if one consider production of the geographical (topographic) data at the national (state) level, i.e. - National wide mapping like strict obligation of the responsible governmental administration organization financed by the government from the state budget and with data kept as a state secret and - Mapping left completely to the market and private enterprises where government is only one of the potential customers in the market in accordance to the present and near future state needs. As usual, these extreme alternatives are not strictly implementable because of several reasons and besause each of them has important and significant disadvantages. Implementable "model" for each country or state is somewhere in between of these extreme alternatives where some pragmatic reasons must have influence on their mutual balance and adjustment to the general and specific state setting and local conditions. Croatian answer to mentioned alternatives is a "model" defined on few following main elements: - Specific and standardized geodetic products (geographical data and information's), their definition, specification, planning of production, financing, distribution to users (customers), etc. are the responsibility of the appropriate state civil administration body, i.e. SGA. Produced data or products have got no status of state secret data but copyright belongs to the state. Different users, from private persons or companies to other government institutions have the possibility to use and pay the usage of data or products for declared purpose in accordance with transparent and acceptable SGA price list. Production is financed partly from the state budget (taxpayer's money), partly by local municipalities or some other investors interested in specific product, for example: Croatian Waters, Croatian Forests, etc. Main orientation in planning of production is defined by user needs and SGA capability to achieve actuality and availability of products with appropriate delivery time (that can be achieved in the frame of objective present Croatian conditions). - Production of previously mentioned specific and standardized products is completely directed to the private companies specialized and infrastructurally capable for organizing and executing efficient production with appropriate level of quality and homogeneity of products in accordance with SGA product specifications. Production is connected with public and transparent procurement procedures organized and conducted by SGA with main purpose to achieve most efficient and productive results – guarantied quality of products in accordance with product specifications produced for less money. - Quality assurance and quality control of products produced by private companies is main responsibility of CGI. In principle CGI is, apart a fact that is connected in work with SGA on same programs, stand alone (independent) professional institution specialized for undertaking quality control activities to assure quality and homogeneity of products. Line of responsibility between SGA and CGI is very clear due to fact that SGA is administrative government body with - 44 - administrative and normative responsibilities and functions and CGI is professional one. Quality control system is based on transparency, taking into account fact that best controllers of products quality should be producers themselves, e.g. private companies. Described "Croatian model" is a quite young model and his implementation is not completely finished yet. Lots of activities are in realization simultaneously, first of all activities regarding building up CGI's capacities and infrastructure to undertake QC work, coordination between SGA, CGI and private companies, improvement of production regarding product specifications, procedures and methods, introduction of new products, etc. So far achieved results are satisfactory and all recent activities are showing that in Croatian circumstances and conditions "model" is giving expected benefits. 4. QUALITY CONTROL Recognizing the most important elements of "Croatian model" and high motivation to improve geodetic and surveying fields of work, especially with respect to Quality Control, the Kingdom of Norway decided to give Croatia support and assistance for consulting services, efficient recent technologies transfer, specialization, education and training of Croatian professionals and capacity building of CGI to be able to significantly improve and implement QC work. In the mentioned setting, direct technical and financial support, and assistance in planning, development and realization of a very important, significant and complex project named Croatian-Norwegian GeoInformation Project -CRONO GIP, is given at the end of 2001. CRONO GIP realization started in June 2002 and the expected end of project is December 2003 Within the frame of CRONO GIP, objectives, expected results and planned activities are in accordance with fundamental strategic decision that CGI should be the main independent quality controller of "geodetic products" produced by private geodetic and surveying companies at the state level. In that sense, one should consider that the project activities at the moment are related to the three main geodetic products, i.e. digital topographic (vector) data, TK25 and DOF. The main objective: - CGI shall be able to control the quality of geographic data (geodetic products) produced by private companies for the Croatian Government Expected results: - CGI shall be able to perform satisfactory controlling of the quality of topographic (vector) data, TK25 and DOF produced by private companies - CGI shall be able to prepare draft regulations and standards in line with internationally accepted standards, to be applied by private companies for assuring and documenting the production quality. Planned activities: - Specification and verification of controlling procedures and related methods to be applied by CGI taking due notice of internationally accepted standards and methods - Verifying existing regulations and standards for quality assurance in production of geographic data by comparing these to internationally accepted regulations and standards (ISO, CEN, etc.) - Drafting new and improved regulations and standards (if found appropriate) - Specification of the requirements concerning technical equipment, instruments and software needed at CGI to be able to make relevant quality controls - Procurement, installation and testing of instruments, hardware and software needed for quality control - Education, specialization and training in the use of the equipment and software - Practical execution of controls on final products and relevant intermediate data resulting from various steps within the production of TK25 and DOF - Informing relevant users, private companies and public institutions about development of regulations and standards and enhancing the awareness of international standards. In the period from June 2002 till May 2003, intensive activities on the realization of CRONO GIP have been carried out. Simultaneously with procurement of equipment for quality control, trainings of CGI employees and verification of existing Croatian regulations, products specifications and standards, crucial activity is connected with the development and defining of the CGI Quality System based on internationally accepted standards adapted to the Croatian situation. The Quality System should be based (Program Management and Mapping, 2002) on transparent set of documentation consisting of: - General quality guidelines - Producers (private companies) quality plan requirements - Products specifications - Control methods descriptions - Specifications of sampling and tolerances for rejection and re-work of specific geodetic product - 45 - and should be developed and implemented in three hierarchical levels: - I Level – Base documents describing overall principles of CGI's quality control work - II Level – Base documents defining the products to be controlled, referring to the three basic products: digital topographic (vector) data, TK25 (digital raster and paper form) and DOF - III Level – Procedures and checklists necessary for undertaking all control work. In addition to the three basic products involved in CGI's quality control activities additional products (sub-products) are also included having in mind important intermediate steps in the production processes: Aerial photo and ground control, Aerotriangulation, Scanned photo and Digital Terrain Model (DTM). Important attention in realization of CGI's quality control system is given to the development of new and the improvement of existing Product Specifications to insure appropriate and transparent quality of production of the Topographic Data mapped and produced from aerial photos in the scale of 1:20000 including quality elements and sub-elements and tolerances like fundamental basis for quality control. Precise and detailed Product Specifications are of great importance not only for CGI's control work but for producers, users and government institutions as well. Development and implementation of CGI's Quality System is still, till the end of May 2003, an ongoing process with a lot of results and significant enhancements of existing CGI's capacities to undertake very important activities regarding geodetic products quality control. Till the moment of completing the work on this paper, all CRONO GIP activities have not been concluded yet. In accordance with the general project setting they are in simultaneous realization with specification and documentation development, trainings on job, definition of practical procedures and methods for quality control are overlapping each other. It should be emphasized that excellent collaboration of responsible institutions, companies and people involved in the project realization exists at all levels, beginning with formal level of coordination between SK, SGA and CGI to the level of professional work and collaboration between Norwegian and Croatian consultants with SGA and CGI employees. On the basis of so far achieved results it is realistic to expect that the capacities and capabilities of CGI will be significantly enhanced and improved in a very limited time frame and that CGI will be able to maintain and undertake all quality control works in the future with appropriate transparency and efficiency for the benefit of all involved parties. 5. CONCLUSION Implementation of the "Croatian model" regarding strategy and quality control of official geographic data production is one of the examples how each country or state by following international and European experiences tailored and customized to specific national conditions can build their own specific solutions. That solution is still under development regarding implementation on practical every day work level, connected with technology and knowledge transfer, education, training and specialization, documentation development, coordination of involved parties, etc. It can be expected that many of already unsolved or at least not efficiently solved elements will be improved in future period on the basis of defined strategy and on the basis of clear and transparent policies. REFERENCES Official newspaper, 1999. The Law of State survay and Real Estate Cadastre. The Republic of Croatia, No. 128/99, Zagreb, Croatia. Official newspaper, 2001. Program of State Survey and Real Estate Cadastre for the Period 2001-2005. The Republic of Croatia, No. 64/01, Zagreb, Croatia. Program management and mapping, 2002. CRONO GIP Croatian Norwegian GeoInformation Project Inception study report, Croatiann Geodetic Institute, September 2002, Zagreb, Croatia. State geodetic administration, 2001. Catalogue of products. Zagreb, Croatia. Statens kartverk, 2001. Terms of reference for the implementation of component b) and c) of the Norwegian assisted Project in Croatia for enhancing the capabilities of the Croatian Government to build a National Spatial Data Infrastructure. Appendix A to the Contract, Oslo, December 2001, Norway. Statens kartverk, 2002. Agreement for improving real estate information and geographic data infrastructure in Croatia, Zagreb, December 2002, Croatia. - 46 - CAMBRIDGE CONFERENCE 2003 "NATIONAL MAPPING – SHAPING THE FUTURE"* Željko Bačić, Nevio Rožić Od 1928. godine, a motivirana prvim Internacionalnim geografskim kongresom (International Geographic Congress) koji je okupio vodeće geodete tog vremena, započela se u Cambridge-u redovito održavati i Imperijalna konferencija geodetskih dužnosnika (Empire Conference of Survey Officers) u organizaciji Britanske kolonijalne komisije za izmjeru (British Colonial Survey Committee). Obzirom da je konferencija bila vrlo produktivna i da je polučila zamjetne rezultate, ponovno je organizirana 1931. godine, a nakon toga se u nizu, sve do posljednje održane 2003. godine, redovito održavala svake četiri godine. Od 1995. godine profil i sadržaj konferencije bitno je izmijenjen, jer je postala internacionalno mjesto okupljanja službenih predstavnika nacionalnih kartografskih organizacija, s izrazito naglašenim sadržajima uzajamne razmjene znanja i iskustava, definiranja zajedničkih vizija i strategija, međusobnog upoznavanja i stvaranja veza, diskusije, rasprave, razmjene mišljenja i realizacije zajedničkih ciljeva. Obzirom da se tijekom dugog vremena tradicijski održava u Cambridge-u konferencija je dobila ime "Cambridge Conference". U razdoblju od 20. do 25. srpnja 2003. godine održala se sukladno prethodno objašnjenoj tradiciji "Cambridge Conference 2003" čiji je sadržaj i područje interesa, više od 250 učesnika iz 76 zemalja sa svih kontinenata, bila nacionalna kartografija kao temeljno sredstvo za oblikovanje budućnosti ("National mapping – shaping the future"), obzirom na činjenicu da je u posljednjem vremenskom razdoblju svijest o značaju i ulozi geografskih podataka i informacija u: definiranju razvoja, donošenju odluka na svim razinama, planiranju, gospodarstvu, potrebama građana i drugim aktivnostima, postala nedvosmisleno i opće prepoznatljiva. Konferencija se održala u prostorima St John's Colledge-a, Cambridge, u organizaciji Ordnance Survey-a. Ispred organizatora voditelj konferencije bila je gospođa Vanessa Lawrence, glavna i izvršna direktorica Ordnance Survey-a. St John's Colledge-a, Cambridge Treba naglasiti da je organizacija konferencije, kako u razdoblju priprema, tako i tijekom održavanja, u svim elementima formalnog i neformalnog dijela bila besprijekorno učinkovita i kvalitetna. Formalni sadržaj konferencije obuhvatio je niz tematski objedinjenih sesija i radionica s izrazito naglašenom potrebom za "živom" raspravom i diskusijom, dok je neformalni dio bio obogaćen nizom prigoda za neformalni razgovor, međusobno upoznavanje i razmjenu informa-cija. U sklopu svake od tematskih sesija ili radionica znatno više vremena bilo je namijenjeno diskusijama nego izlaganju radova, a izlaganja su bila sažeta i strogo vremenski ograničena. Stoga su i prije samog početka konferencije, a u svrhu pravodobne pripreme za diskusije, svim učesnicima bili dostavljeni objedinjeni sadržaji i radovi autora, sadržani na konferencijskom CD-ROMu te su istodobno bili postavljeni i na službene Internet Objavljeno u Geodetskom listu 2003 godine (Rožić, N., Bačić, Ž.: Cambridge Conference 2003 "National mapping – shaping the future". Geodetski list, 2003, 3, 220-222). * - 47 - stranice konferencije http://www.cambridgeconference2003.com/. Ujedno, radovi su objedinjeni i otisnuti na klasičan način u zborniku radova konferencije. U sklopu formalnog dijela konferencije održano je ukupno 9 sesija, od kojih su dvije sesije bile namijenjene isključivo radionicama. Obzirom na vremenski raspored učesnici su, sukladno vlastitom izboru i interesu, mogli sudjelovati najviše u radu dviju radionica unutar pojedine sesije. U nastavku se, obzirom na opsežnost broja radova i autora, daje pregled sesija, voditelja sesija, tematsko određenje radova u sesijama i radionicama te broj radova obuhvaćenih programom: Prva sesija (21. srpnja 2003. godine). Voditeljica: Vanessa Lawrence (Director general and chief executive, Ordnance Survey, Great Britain). U okviru sesije obavljeno je, uz iskazivanje dobrodošlice učesnicima konferencije, službeno otvorenje i predstavljanje uvodnog rada konferencije pod nazivom "Budućnost okosnice podataka: odmak od lista karte". Druga sesija, 21. srpnja 2003. godine. Voditelj: Qassim Al Ghanim (Ministry of Municipal Affairs and Agriculture, Qatar). Tema sesije bilo je značaj nacionalne kartografije u svijetu koji se neprekidno mijenja. Predstavljena su četiri rada. Treća sesija, 22. srpnja 2003. godine. Voditelj: Robin McLaren (Know Edge Ltd. UK). Sadržaj sesije bio je objedinjen traženjem odgovora na simbolički postavljeno pitanje "Tko plaća kartografa?". Predstavljeno je 6 radova. Četvrta sesija, 22. srpnja 2003. godine. U sklopu sesije održane su četiri tematski i sadržajno objedinjene radionice: - tema prve radionice bila je pribavljanje političke podrške i financijskih sredstava za potrebe nacionalne kartografije. Voditelj: Bryson Morebodi (Royal Institution of Chartered Surveyors, UK). Predstavljena su 4 rada. - tema druge radionice bilo je obrazovanje stručnjaka i kadrova za budućnost, u svjetlu intenzivnih tehnoloških promjena. Voditelj: Jean Cooper (Natural Resources Canada). Predstavljena su tri rada. - tema treće radionice bila je tehnologija u okružju kartografije i prostornih podataka. Voditelj: John Spital ( Land Information New Zeland). Predstavljena su četiri rada. - tema četvrte radionice bila su pravna pitanja u svezi nacionalnih prostornih i kartografskih podataka. Voditelj Alex Griffin (Ordnance Survey, GB). Predstavljena su četiri rada. Peta sesija, 23. srpnja 2003. godine. U sklopu sesije održane su četiri tematski i sadržajno objedinjene radionice: - tema prve radionice bila je transformacija nacionalnih kartografskih organizacija u smislu učinkovitog rada i funkcioniranja. Voditelj: Amithaba Pande (Department of Science and Technology, India). Predstavljena su četiri rada. - tema druge radionice bila je izgradnja nacionalnih infrastruktura prostornih podataka. Voditelj: Peter Holland (Geoscience, Austria). Predstavljena su tri rada. - tema treće radionice bilo je razumijevanje i prepoznavanje potreba korisnika te ukupnog vođenja poslovanja i rada na ekonomskim osnovama. Voditelj: Derek Clarke (Surveys and Mapping, South Africa). Predstavljena su četiri rada. - tema četvrte radionice bio je utjecaj tehnologija na razvoj specifičnih aplikacija vezanih uz prostorne podatke. Voditelj: Zeljko Bačić (Državna geodetska uprava, Hrvatska). Predstavljena su četiri rada. Šesta sesija, 23. srpanj 2003. godine. Voditelj: Santiago Borrero (Institute for Pan American Geography and History, Columbia). Sadržaj sesije odnosio se na opće okružje i kontekst infrastrukture prostornih podataka. Predstavljena su četiri rada. Sedma sesija, 24. srpanj 2003. godine. Voditelj: Barbara Ryan (US Geographical Survey, US). Sadržaj sesije odnosio se na interakciju i upošljavanje privatnog sektora u proizvodnji nacionalnih prostornih i kartografskih podataka. Predstavljeno je 6 radova. Osma sesija, 24. srpanj 2003. godine. Voditelj: Joakim Ollen (National Land Survey of Sweden). Sadržaj sesije bilo je predviđanje budućih trendova i procesa vezanih uz utjecaj tehnologije na aktivnosti nacionalnih kartografskih organizacija. Predstavljeno je šest radova. Deveta sesija, 24. srpanj 2003. godine. Voditelj: Vanessa Lawrence (Director general and chief executive, Ordnance Survey, Great Britain). U sklopu sesije donesene su rezolucije konferencije, dogovorene i prihvaćene određene aktivnosti koje će se obaviti do naredne konferencije te je konferencija službeno okončala svoj rad. U sklopu neformalnog dijela konferencije bio je organiziran opsežan i relativno raznolik program koji je obuhvatio: - održavanje izložbe "The Great Arc of India", posvećenoj izmjeri indijskog potkontinenta, - prikazivanje prigodnog filma posvećenog tijeku i sadržaju izmjere indijskog potkontinenta, - održavanje specijalizirane izložbe proizvoditelja informatičke i geodetske opreme, - održavanje prigodnog konferencijskog predavanja "Hotine lecture" kojeg je održao profesor - 48 - Gordon Convay, predsjednik Rockefeller fondacije, posjet institucijama: Ordnance Survey u Southamptonu, Land Registry, Royal Geographical Sociaty i Defence Geographic and Imaginery Agency u Londonu, - posjet instituciji Royal Institution of Chartered Surveyors u Londonu. U radu konferencije bila je zastupljena i Republika Hrvatska, predstavnicima Državne geodetske uprave Republike Hrvatske u svojstvu nacionalne kartografske organizacije (nadležnost za nacionalne prostorne podatke i kartografske proizvode) i Hrvatskoga geodetskog instituta. Tako su u sklopu sedme sesije konferencije predstavljena dva uzajamno povezana rada: - Baćić, Ž., "Outsourcing whole production out of NMO: Croatia as an example", - Rožić, N., "Strategy and System of Quality Control of the Official Geographic Data produced by Private Companies in Croatia". - Prezentacija Ž. Bačića Prezentacija N. Rožića Citirani radovi pružili su učesnicima konferencije uvid u strategiju, način i rezultate procesa sustavnog uključivanja privatnog sektora (geodetske tvrtke) u proizvodnju prostornih podataka i kartografskih proizvoda za nacionalne potrebe. Model koji se primjenjuje u Hrvatskoj specifičan je u nizu elemenata u odnosu na iskustva i praksu europskih i drugih država te je izazvao zamjetan interes i diskusiju učesnika konferencije. U okviru diskusije, a nakon prezentacija, za predstavljeni su model učesnici konferencije učestalo koristili naziv "Hrvatski model", što posredno ukazuje kako na njegovu specifičnost, tako na interes i pozornost koji su mu pridodali učesnici konferencije. Također, zanimljivo je naglasiti i činjenicu da je jedan od zaključaka sadržanih u citiranim radovima i prezentacijama, u djelomice redefiniranom obliku, postao i sastavni dio rezolucije konferencije, tj. precizirao je određenje da svaka od država sljedeći zajedničku viziju izgradnje nacionalne strukture prostornih podataka i proizvodnje kartografskih proizvoda ima, ne samo mogućnost već i puno pravo izgrađivati i slijediti svoj vlastiti model. Sukladno tomu, može se ocijeniti da su se radovi, sadržajno i tematski te svojom razradom učinkovito, aktualno, koherentno i meritorno uklopili u okvir i sadržaj konferencije te tako pridonijeli afirmaciji Republike Hrvatske i njenih institucija. - 49 - - 50 - CROATIAN-NORWEGIAN GEOINFORMATION PROJECT* Nevio Rožić, Slavko Lemajić, Mladen Rapaić ABSTRACT Recognising specific needs of the Republic of Croatia in transition period and high motivation of responsible Croatian state institutions to improve geodetic and surveying professional activities at state level, the Kingdom of Norway decided to give Croatia support and assistance for consulting services, efficient technology transfer, specialisation, education, training of Croatian professionals and capacity building of Croatian institutions to be able to significantly improve their work. In the mentioned setting, direct technical-financial support and assistance in planning, development and realization of a very important, significant and complex project named Croatian-Norwegian GeoInformation Project (CRONO GIP) is given. On the basis of efficient collaboration between Norwegian Mapping Authority (Statens Kartverk), Program Management and Mapping consultant company on the Norwegian side and State Geodetic Administration and Croatian Geodetic Institute on the Croatian side, CRONO GIP started to be realized during June 2002. Regarding the Croatian Geodetic Institute participation in project realization, the main objectives are establishment and implementation of the Quality Control System which will assure efficient, transparent and professional quality control of some specific geodetic products: topographic (vector) data, topographic maps in the scale of 1:25000 and orthophoto maps in the scale of 1:5000, produced for the Croatian Government by private companies. Objectives, expected results and CRONO GIP activities are definded and specified in accordance with the fundamental idea that Croatian Geodetic Institute has become, apart from the fact that has been recently founded and established government institution, the main quality controller of mentioned geodetic products. KEYWORDS Croatian-Norwegian collaboration, Technology transfer, Education Geoinformation project, Quality control, Croatian Geodetic Institute and training, 1. INTRODUCTION After acquiring the independence and sovereignty at the beginning of the 90-ties and after suffering from war until 1995, the Republic of Croatia initiated significant and extensive activities in the field of geodetic and surveying works at the state level. In completely new circumstances, Croatia has been forced in a very short period to reorganize and establish their own government institutions responsible for geodetic and surveying works important for state at the whole state territory, to define and improve appropriate legal fundament for geodetic and surveying activities, to motivate and improve production in private companies, etc. Among all activities, special importance is given to building and development of the National Spatial Data Infrastructure and systematic production of digital (vector) topographic data, renewal and production of topographic map series and orthophoto maps for the whole state territory, renewal and technological modernization of cadastre and land registry in the sense of efficient market economy and protection of private ownership. Some of very important elements and results regarding mentioned activities achieved after 1995 are: - From the beginning of 1999, the new Law of State Survey and Real Estate Cadastre delivered by Croatian Parliament is valid and a set of new important bylaws has been delivered - State Geodetic Administration (SGA) as the main government administration body responsible for geodetic and surveying works at the whole state territory is reorganised and modernized - Croatian Geodetic Institute (CGI) like completely new government institution for specialized geodetic and surveying works is founded and started to work - Program of State Survey and Real Estate Cadastre for the period 2001-2005 is delivered by Croatian Parliament and started to be implemented Predstavljeno na International Society for Photogrammetry and Remote Sensing (ISPRS) WG VI/3 Workshop-u: "GeoInformation for Practice", održanom u Zagrebu 15.-18.10.2003. godine. Objavljeno u zborniku radova (Rožić, N., Lemajić, S., Rapaić, M.: Croatian-Norwegian Geoinformation Project. Proceedings of the International Society for Photogrammetry and Remote Sensing (ISPRS) WG VI/3 Workshop: "Geo-Information for Practice", 15-18 October 2003, ISSN 1682-1750, Zagreb, Croatia, 224227). * - 51 - Production of new topographic map series in scale 1:25000 (TK25) and orthophoto maps in scale 1:5000 (DOF) covering state territory is started, including production of topographic (vector) data, etc. Apart fact that Croatia has much more than hundred years old tradition in carrying out geodetic and surveying works lot of disadvantages are connected with fast and efficient improvement of existing situation and realization of planned activities at state level. Some of them are: - Quite complicated and to Croatia not completely appropriate geodetic and surveying heritage from the former Yugoslavia - Very fast and complex state transition period overlapping with war situation, including all economic and financial consequences - Very fast worldwide changes in technology, production infrastructure, HW&SW solutions and specialised knowledge in field of production and distribution of geoinformations and geodata, etc. - Limited state resources (state budget, level of organization, infrastructure resources, etc.) for autonomous fast and efficient solving of quite complex tasks like for example development of the National Spatial Data Infrastructure, etc. - Lack of experience and recent knowledge regarding some specific fields of professional work, for example Quality Control (QC) of "geodetic products" or more widely, the geodata especially related to the international and European standards (ISO, CEN), etc. Recognising most important elements of Croatian situation and high motivation to improve geodetic and surveying fields of work, some European countries decided to give Croatia support and assistance for consulting services, efficient recent technologies transfer, specialisation, education and training of Croatian professionals and capacity building of Croatian responsible institutions to be able to significantly improve their work. In the mentioned setting, the Kingdom of Norway decided to give to the Republic of Croatia and responsible Croatian institutions direct technical and financial support, and assistance in planning, development and realization of a very important, significant and complex project named Croatian-Norwegian GeoInformation Project (CRONO GIP). Apart from having great significance and meaning for the whole state CRONO GIP has got at same time enormous significance for SGA and CGI's development. It should be pointed out that CGI is a completely new institution in Croatia, recently founded and functioning from December 2001. The assistance to CGI in building and developing capacities for specialised professional works, including technology transfer, specialization, education, training, infrastructure building (equipment), etc. is the basis for efficient improvement and enhancement of CGI's existing work and possibility to upgrade joint work of SGA, CGI and private companies within the frame of realizing the Program of State Survey and Real Estate Cadastre for the period 2001-2005. - 2. CRONO GIP CONTENT Norwegian assistance to Croatia has been initiated by request of the Government of the Republic of Croatia to the Norwegian Ministry of Foreign Affairs. Norwegian Mapping Authority – Statens Kartverk (SK) has been contracted to act on behalf of Norway in the process of planning and implementation of CRONO GIP, together with SGA and CGI on Croatian side. During December 2001 the initial Agreement between SK, SGA and CGI was signed in Oslo for the implementation of the project for enhancing the capabilities of the Croatian Government to build a National Spatial Data Infrastructure. After tendering procedure executed in Norway consultant company, Program Management and Mapping (PMM) has been selected to carry out the consultancy work and in the same time some consultants from Croatian private companies were included in PMM consultant team. CRONO GIP has formally started to be realized during June 2002. On the basis of CRONO GIP, the realization of additional extension of the project has been defined at the end of 2002. During December 2002 the second Agreement between SK, SGA and CGI has been signed in Zagreb regarding significant content extension with respect to the initial CRONO GIP agreement. Because of that one can recognize the realization of two very strongly connected projects CRONO GIP I and CRONO GIP II. The main areas of CRONO GIP I activities (Statens Kartverk, 2001): - Establishment of the capacity within SGA to scan and vectorise existing paper maps (cadastral maps, Croatian basic maps in scale 1:5000, etc.) - Development and implementation of a database within SGA for storage and use of data resulting from the on-going production of new topographic maps in the scale 1:25000 - Establishment of a capacity within CGI to control the quality of geographic data produced for the Croatian Government by private companies. Main areas of CRONO GIP II activities (Statens Kartverk, 2002): - Production of digital cadastral maps within SGA to enhance the capacity developed by CRONO GIP I - 52 - Scanning and vectorisation of existing topographic maps in the scale 1:5000 within SGA Enhancement of capacity of CGI to control quality of geodetic works Establishment of a pilot geographic information system for the Croatian national park of Kornati. In the following chapters special attention will be given to CRONO GIP I activities directly connected with CGI, apart from the fact that SGA and CGI are strongly dependant and mutually involved in the project realization. - 2.1. CRONO GIP OBJECTIVES, EXPECTED RESULTS AND ACTIVITIES RELATED TO THE CGI Within the frame of CRONO GIP I, objectives, expected results and planned activities are in accordance with fundamental strategic decision that CGI should be the main quality controller of "geodetic products" produced by private geodetic and surveying companies at the state level. In that sense, one should consider that the project activities are related to the three main geodetic products, i.e. digital topographic (vector) data, TK25 and DOF. Main objective: - CGI shall be able to control the quality of geographic data (geodetic products) produced by private companies for the Croatian Government Expected results: - CGI shall be able to perform satisfactory controlling of the quality of topographic (vector) data, TK25 and DOF produced by private companies - CGI shall be able to prepare draft regulations and standards in line with internationally accepted standards, to be applied by private companies for assuring and documenting the production quality. Planned activities: - Specification and verification of controlling procedures and related methods to be applied by CGI taking due notice of internationally accepted standards and methods - Verifying existing regulations and standards for quality assurance in production of geographic data by comparing these to internationally accepted regulations and standards (ISO, CEN, etc.) - Drafting new and improved regulations and standards (if found appropriate) - Specification of the requirements concerning technical equipment, instruments and software needed at CGI to be able to make relevant quality controls - Procurement, installation and testing of instruments, hardware and software needed for quality control - Education, specialization and training in the use of the equipment and software - Practical execution of controls on final products and relevant intermediate data resulting from various steps within the production of TK25 and DOF - Informing relevant users, private companies and public institutions about development of regulations and standards and enhancing the awareness of international standards. CRONO GIP I realization started in June 2002 and the expected end of project is December 2003 including CRONO GIP II extension regarding CGI quality control activity. It should also be mentioned that apart from financing the consultancy services, the Norwegian funding within the frame of CRONO GIP I covers the amount of 600.000,00 NOK for procurement of equipment (hardware and software) and training with additional CGI participation in project with 400.000,00 NOK. In similar way, within the frame of CRONO GIP II, the additional amount of 310.000,00 NOK from Norwegian side and 500.000,00 NOK from Croatian side are set aside. 3. REALIZATION OF CRONO GIP I In the period from June 2002 till May 2003, intensive activities on the realization of CRONO GIP I have been carried out. Simultanesously with procurement of equipment for quality control, trainings of CGI employees and verification of existing Croatian regulations, products specifications and standards, crucial activity is connected with the development and defining of the CGI Quality System based on internationally accepted standards adapted to the Croatian situation. The Quality System should be based (Program Management and Mapping, 2002) on transparent set of documentation consisting of: - General quality guidelines - Producers (private companies) quality plan require-ments - Products specifications - Control methods descriptions - Specifications of sampling and tolerances for rejection and re-work of specific geodetic product and should be developed and implemented in three hierarchical levels: - I Level – Base documents describing overall princip-les of CGI's quality control work - 53 - II Level – Base documents defining the products to be controlled, referring to the three basic products: digital topographic (vector) data, TK25 (digital raster and paper form) and DOF - III Level – Procedures and checklists necessary for undertaking all control work. In addition to the three basic products involved in CGI's quality control activities additional products (sub-products) are also included having in mind important intermediate steps in the production processes: Aerial photo and ground control, Aerotriangulation, Scanned photo and Digital Terrain Model (DTM). Important attention in realization of CGI's quality control system is given to the development of new and the improvement of existing Product Specifications to insure appropriate and transparent quality of production of the Topographic Data mapped and produced from aerial photos in the scale of 1:20000 including quality elements and sub-elements and tolerances like fundamental basis for quality control. Precise and detailed Product Specifications are of great importance not only for CGI's control work but for producers, users and government institutions as well. Development and implementation of CGI's Quality System is still, till the end of May 2003, an ongoing process with a lot of results and significant enhancements of existing CGI's capacities to undertake very important activities regarding geodetic products quality control. - 3.1. EQUIPMENT AND TRAININGS Within the frame of CRONO GIP I, the realization set of quite important activities consists of specification, procurement, testing and implementation of the technical equipment, hardware and software needed at CGI to be able to make relevant quality controls paralel with specialization, education and training of CGI's employees to efficiently use technical equipment. These activities will be almost fully finished till the end of May 2003 except the training at photogrammetric digital station and practical control training on final geodetic products. With respect to the equipment, with already existing CGI equipment infrastructure, following items are procured and they started to be used in every day work: - Digital photogrammetric station hardware with appropriate photogrammetric software - GPS hardware and software - CAD and GIS software - DTM software - Plotting and presentation hardware. Education and training of CGI employees regarding procured equipment and the whole content of CRONO GIP I activities was organised and already almost concluded at two levels. The first level was realized within the frame of hardware/software vendor trainings: - Feature Manipulation Engine (FME) - Oracle Spatial - GPS hardware and software, while the second level was realized within the frame of direct consultations during the organized trainings: - Microstation - Geomedia - Scope, etc. with lots of elements of general and specific knowledge transfer in the fields of organization, management and execution of specific tasks. Like very illustrative example of training efficiency and overall knowledge transfer, regarding the fact that specialised works has never be done in CGI before CRONO GIP realization, the quality control of upgraded and topologically cleaned digital topographical (vector) data produced by six Croatian private companies has been carried out with remarkable success. 3.2. FURTHER ACTIVITIES Till the moment of completing the work on this paper, all CRONO GIP activities have not been concluded yet. In accordance within general project setting they are in simultaneous realization with specification and documentation development, trainings on job, definition of practical procedures and methods for quality control are overlapping each other. It should be emphasised that excellent collaboration of responsible institutions, companies and people involved in the project realization exists at all levels, beginning with formal level of coordination between SK, SGA and CGI to the level of professional work and collaboration between Norwegian and Croatian consultants with SGA and CGI employees. On the basis of so far achieved results it is realistic to expect that capacities and capabilities of CGI will be significantly enhanced and improved in a very limited time frame and that CGI will be able to - 54 - maintain and undertake all quality control works in future time with appropriate transparency and efficiency for the benefit of all involved parties. 4. CONCLUSION CRONO GIP is one of very good examples of internationally planned and executed professional projects containing elements of technology and knowledge transfer, education, training and specialization in specific field of professional work. Efficiency of realization is based on several important elements, i.e.: - Very clear and precise definition of project objectives, expected results and activities (Terms of Reference) with precise and strict planning, management and project execution - Excellent coordination between responsible institutions, companies and state bodies involved in realization, - Excellent and fruitful collaboration between Norwegian consultants, Croatian experts and SGA/CGI employees, - High level of motivation of Croatian institutions to improve and upgrade their own professional activities following recent international and European experiences and technological development - Appropriate technical level and knowledge on Croatian side like basis for "easy", logical and sustainable organizational and professional upgrade and improvement - Partially Croatian financial funding of project realization, etc. Additionally, if one considers the impact of CRONO GIP realization on CGI as a very young and still not completely developed Croatian professional institution, great benefit can be recognized in full extent from the work in multi-language environment to the technological and other integration into the geodetic space of the united Europe. In that sense, the specialization and education of CGI's employees, qualified engineers of geodesy already is and will be of great importance for all future works. After all, technical and financial help of the Kingdom of Norway, through realization of CRONO GIP, will significantly improve and speed up specific professional activities in the Republic of Croatia as one of the central European transition countries. REFERENCES Program Management and Mapping, 2002. CRONO GIP Croatian Norwegian GeoInformation Project Inception study report, Zagreb, Croatia. Statens Kartverk, 2001. Terms of reference for the implementation of component b) and c) of the Norwegian assisted Project in Croatia for enhancing the capabilities of the Croatian Government to build a National Spatial Data Infrastructure. Appendix A to the Contract, Oslo, Norway. Statens Kartverk, 2002. Agreement for improving real estate information and geographic data infrastructure in Croatia, Zagreb, Croatia. ACKNOWLEDGEMENTS Croatian Geodetic Institute wishes to acknowledge his great appreciation and gratitude to all Norwegian official state and professional institutions, companies and people for their assistance and support which have contributed in one way or another towards the successful planning, implementation, tracking and realization of the Croatian-Norwegian GeoInformation Project. CGI especially wishes to acknowledge his appreciation, gratitude and thanks to the Ambassador of Norway in Zagreb, His Excellency Mr. Knut Tørrasen and to the officials of the Norwegian Mapping Authority: Director General Mr. Knut O. Flåthen, Senior Adviser Mr. Helge Onsrud and Senior Engineer Mr. Kjell E. Aadnevik. Finally CGI wishes to express its deepest thanks to CRONO GIP team leader Mr. Jostein Sageie and the whole PMM consultant's team for all fruitful discussions, recommendations, guidance and efforts invested in the realization of the project. - 55 - - 56 - IMPROVEMENT OF QUALITY CONTROL SYSTEM IN CROATIA* Slavko Lemajić, Nevio Rožić, Mladen Rapaić ABSTRACT Croatian Geodetic Institute (CGI) was founded in February 2001 and started with professional work at December of 2001. CGI is an independent institution but working closely with State Geodetic Administration (SGA). According to Law on State Survey and Real Estate Cadastre (Croatian Parliament, 1999) CGI is responsible for scientific geodetic and surveying works and for quality control of geodetic products produced by geodetic companies. At the beginning of professional work CGI started with performing of digital orthophoto control and analogue topographic maps control. At that time the CGI quality system was not in accordance with ISO standards. The Book of Ordinance (State Geodetic Administration, 2001) was the key document for ensuring quality control. Lack of software systems and hardware infrastructure, supporting data necessary for quality control, procedures and formal QC documentation were the main reason to start establishment and development of new CGI Quality System for quality control of geodetic products. Croatian-Norwegian Geoinformation Project (CRONO GIP) started in June 2002. Implementation of component c) of the Norwegian assisted Project in Croatia for enhancing the capabilities of the Croatian Government to build a National Spatial Data Infrastructure has according to Terms of reference (Statens Kartverk, 2001) three objectives: CGI shall be able to control the quality of topographic data produced by geodetic companies for SGA, CGI shall be able to perform satisfactory controlling of the quality of topographic maps and orthophotos produced by geodetic companies and CGI shall be able to prepare draft regulations and standards in line with international standards, to be applied by geodetic companies for assuring and documenting quality in the production of geographic data. Before Implementation of CRONO GIP results, CGI performed the Test Quality Control. The Dataset, which was the subject of Control, CGI have controlled according to Specification which are made for Data Upgrade. The Results with Reports of Test Control are delivered to Producers for corrections. After Corrections the Structure of Dataset was acceptable for further methods of control. KEYWORDS Geoinformation project, Data upgrade, Quality control, Quality Plan, Croatian Geodetic Institute, ISO 1. INTRODUCTION At the end of 2001 CGI started with professional work in the field of control of orthophoto in the scale 1:5000 and control of topographic map in the scale 1:25000. The control of these products was not based on ISO rules. Lack of experience, equipment and specifications which were needed for control, demanded to make full control of these products. Also, before establishment of CGI there was no institutional system for making quality control but CGI started with improvement of the quality of products. CRONO GIP which started in June 2002 had a main goal to improve quality control system in CGI. Consultant Team made Inception study report (Program Management and Mapping - PMM, 2002) for producing detailed project plan, for reviewing all activities defined in Terms of Reference, for verifying the project objectives and local awareness for the Project, setting guidelines and procedures for execution and building the team. The base activity of CRONO GIP which is connected with Croatian Geodetic Institute is to establish capacity in CGI to control the quality of geodetic data produced by geodetic companies for State Geodetic Administration. From the beginning, the planned activities if the Project are: - Specification and verification of controlling procedures and methods for CGI according to ISO - Verification of existing documentation with comparing to ISO standards - Drafting new regulations and standards - Specification and procurement of equipment (hardware and software) - Education in the use of new equipment (training) Predstavljeno na International Society for Photogrammetry and Remote Sensing (ISPRS) WG VI/3 Workshop-u: "GeoInformation for Practice", održanom u Zagrebu 15.-18.10.2003. godine. Objavljeno u zborniku radova (Lemajić, S., Rožić, N., Rapaić, M.: Improvement of Quality Control System in Croatia. Proceedings of the International Society for Photogrammetry and Remote Sensing (ISPRS) WG VI/3 Workshop: "GeoInformation for Practice", 15-18 October 2003, ISSN 1682-1750, Zagreb, Croatia, 168172). * - 57 - - Practical execution of controls on products and making the reports. The realization of the Project is based on a set of documentations: - Products and product specifications - Quality plan - Procedures and checklists - Reporting. 1.1. PRODUCTS Product is a set of work results, which can be used for several purposes. The Product is defined by Product Specifications. For each Product, requirements are set to the Process leading up to the final product. These processes are subject to Process Specifications. The process specification will mainly be required to process documentation. The Process Specifications are subject to more frequent changes due to development of technology and methodology, compared to the product specifications that are of a more permanent character. Product Specifications and Process Specifications are related to Quality Elements and Quality Sub elements ISO/DIS 19113 and ISO/DIN 19114 (International Organization for Standardization, 2001 and 2002). Each of these elements is described with: - Definition of the quality element/sub element - Specification - Producers documentation requirements. The control of these elements is described with respect to: - Sampling strategy - Accept/reject rules - Quality control method. Following products are defined: - Aerial Photography and Ground Control Points - Scanned Photo - Aerial Triangulation - Topographic Data - Digital Terrain Model (DTM) - Topographic map in scale 1:25000 (TK25) - Digital orthophoto in scale 1:5000 (DOF). 1.2. QUALITY PLAN Quality Plan defines the organization, policies and procedures applied by CGI when undertaking quality control of product deliverables. Developing and inspection plan and execution describes how individual inspections are planned and undertaken. Inspection of a product may consist of many individual inspections. Developing of inspection plan describes the steps to follow when developing an Inspection Plan. The result of this examination shall be written in the Inspection Plan for the Project. The same Inspection Plan template can be used over again for new projects of similar nature. Execution shows the steps to follow when undertaking the Inspection Work. The inspection itself must be new for each project however the procedure can be the same for similar projects. a) The development of a control plan follows the next six steps: - Identification of dataset - when identifying the dataset, the relevance of the data should be emphasized. - Identification of data quality elements - the control might involve one or more quality elements. The control plan will identify all data quality elements and data quality sub elements relevant for the product or service. - Identification of data quality measure - the data quality measure has to be defined. - Identification of tolerances - requirements for geographic information specified as tolerance are standard parts of the specifications for the data set. - Identification of data quality scope - the geographic area for the control and groups of objects has to be identified. A choice has to be done between full inspection and sampling. If sampling is chosen, the size of the scope and geographic location has to be identified. - Identification of control method - the control method has to be defined. b) Execution of inspection contains the following: - Undertake control measurements and calculate Values for data quality measures. True values must be obtained, usually by control measurements. Corresponding values are - 58 - selected from the dataset. The difference between the value of the dataset and the true value is the discrepancy. Based on all differences, the value for the current quality measure can be evaluated. - Compare calculated values for quality measures with tolerances. Values from the control measurements shall be compared with the tolerance of the data quality measure. It has to be decided whether the quality corresponds with the product specifications or not. The result must be significantly worse than the tolerance before the dataset is rejected. - Approval and handling of gross errors/discrepancies. When the control is finished, it has to be decided whether the dataset shall be approved, rejected or if the control shall be expanded. - Reporting. Reporting can be done in two ways: - Prepare a special inspection report - Report as metadata. It is recommended to report by means of inspection reports. 1.3. PROCEDURES AND CHECKLISTS A Checklist is a Formal description of a task mainly built up of boxes to be filled in, ticked or signed. All Procedures and Checklists are controlled by a system of sponsor and custodian where both signatures are required before the documents are released for use. Custodians are responsible for the distribution and revision control of all documents assigned to them. Sponsors authorize the content of the document for use. As a general rule, sponsors are departmental managers. Data quality methods are divided into two main classes, direct and indirect. Direct methods determine data quality through the comparison of the data with internal and/or external reference information. Indirect methods infer or estimate data quality using information on the data such as lineage. The direct evaluation methods are further sub classified by the source of the information needed to perform the evaluation. a) Direct Evaluation Methods - Types of Direct Evaluation Methods: internal and external. - Means of Accomplishing Direct Evaluation: for both external and internal evaluation methods, there are two considerations, automated or non-automated and full inspection or sampling. - Full inspection - Sampling b) Indirect Evaluation Method The indirect evaluation method is a method of evaluating the quality of a dataset based on external knowledge. This external knowledge may include, but is not limited to, data quality overview elements and other quality reports on the dataset or data used to produce the dataset. 1.4. REPORTING Reporting of Data Quality Evaluation Information is possible as: - Reporting in Metadata - Reporting in a Quality Evaluation Report - Reporting Aggregated Data Quality Result. It is recommended to report by means of Inspection Reports. 2. TEST QUALITY CONTROL OF TOPOGRAPHIC DATA Before the end of Project CGI has preformed test quality control of topographic data. Preliminary tasks that are done can be described as: - Verification of existing data according to CROTIS (State Geodetic Administration, 2002) - Data upgrade specification (PMM, 2003) - Quality control of upgraded data. 2.1. VERIFICATION OF EXISTING DATA For verification of existing data six Croatian private companies delivered a part of data from dataset that were the object for comparison with Croatian Topographic Information System (CROTIS) data model. Another objective was how to bring the existing data up to new Specification. The task was - 59 - to determinate differences between datasets and existing specification. It resulted in the the report about the existing data based on examples of six companies. Findings were divided on: - Global remarks to existing specification (or incomplete specification) - Global remarks to all companies - Specific remarks for a single company. 2.2. DATA UPGRADE SPECIFICATION Data upgrade specification describes: - Content of specification - Terminology used in specification - Deliverables - Specification for geometry and topology - Specification for topographic data - DTM specification. According to this Specification companies have upgraded the Data. The main activity in pre qualification process was changing attributes and topological cleaning the data. Such prepared data will be ready for input into database. The integral parts of specifications are: - Object selection criteria - Mapping catalogue - Library of symbols - Quality elements. In the specification, there is also the terminology described that is partly based on Simple Feature Specification by Open GIS Consortium. According to specification, the contractors should deliver final production report and the dataset. Final production report contains Production metadata and other information, Descriptions of topology processing procedures and Descriptions of quality control procedures for important processes. Dataset to be delivered is Topographic vector data in 2D and Digital terrain model (DTM) vector data in 3D. All data should be delivered in „dgn” format (Microstation). Coordinate system of dataset, file names ad media are described too. Specification for geometry and topology describes that delivered data should contain only line string and point geometries. Data topology describes that polygons are not allowed but polygons should be automatically generated from the data. The same rule with requirements for topology is described. Specification of topographic data describes groups of feature classes and representation in „dgn” files. Representation of feature classes is described in „Mapping catalogue” and selection criteria in „Selection criteria” for data capture. Distribution of feature classes is divided by groups, levels and files. The specification also describes which feature classes and in what way they should be represented. There are following feature classes: Toponyms, Buildings, Utility, Transportation and elevated features, Vegetation, Hydrographic and digitized feature. DTM Data Specification contains Digital Terrain model and DTM data processing procedures. DTM features are spot heights, mass points, break lines, form lines and areas of unreliable DTM. In DTM data processing procedures are data preparation, data vectorization, data editing, data specification, quality control and delivery formats. 2.3. DATA UPGRADE QUALITY CONTROL State Geodetic Administration (SGA) contracted data upgrade for six map sheets of Topographic map in scale of 1:25000 (TK25) with six geodetic companies. They upgraded existing dataset according to Data Upgrade Specification and Mapping Catalogue. Before starting the job consultant team of CRONO GIP made training for geodetic companies. Companies delivered upgraded data with technical reports. CGI, in coordination with CRONO GIP Team, made a strategy for quality control. The Strategy contained: - Quality Plan - Quality methods with realization - Results of control - Reports. 2.3.1. QUALITY PLAN Quality Plan defines requirements for quality control of upgraded data and Quality Management System. Quality system in this Quality Plan covered Product of Topographic Data. Quality Plan covered - 60 - following steps: - Control of deliverables - Control according sources - Control of structure of data - Control of topology - Control of DTM dataset. Geodetic companies delivered mainly the following files: - YYYY-MM-DD-<ContractorID>-<MapNumber>-BUILDINGS.dgn - YYYY-MM-DD-<ContractorID>-<MapNumber>-UTILITY.dgn - YYYY-MM-DD-<ContractorID>-<MapNumber>-LANDCOVER.dgn - YYYY-MM-DD-<ContractorID>-<MapNumber>-DIGITISED.dgn - YYYY-MM-DD-<ContractorID>-<MapNumber>-TOPONYMS - YYYY-MM-DD-<ContractorID>-DTM.dgn - YYYY-MM-DD-<ContractorID>-DEM-GRID.dgn - YYYY-MM-DD-<ContractorID>-REPORT.pdf, where YYYY-MM-DD is date of deliverry, ContractorID represent name of company, MapNumber represent map number and at the end content of files with file format. Examples of topographic data and DTM data are shown on Figure 1 and Figure 2: Figure 1: Example of topographic data Figure 2: Example of DTM data Sources which are used for control were Data inventory report, Data upgrade specification and Mapping catalogue. For the control of toponyms there were aslo the old maps of TK25 used. Data structure control included was done acoording to mapping catalogue which describes level, color, line style and weight for linear objects, cell name for point elements and representation point (text) for areal objects. Control of topology included checking closing areas, duplicate lines and boundaries, open boundaries, number of representation points in areas, missing representation points in areas, detecting unused boundaries, etc. Control of DTM included also checking of structure elements in files and deriving DEM from delivered elements and detecting of possible errors. 2.3.2 QUALITY METHODS There are two methods for quality control: - Visual control with Microstation and SCOP - Automatic control of data structure and topology (using FME). Microstation was used for visual control of data. There was a system to control elements, which were wrongly represented before data upgrade process. Mostly, bridges were wrongly represented, roads were without center lines, waters were not represented under bridges (Figure 3) and culverts, creating centerlines were also not enough precise (Figure 4). Visual control of DTM was done with the help of derived shade (tiff format) and DEM (dgn format) as shown on Figure 5. Some questionable parts on raster file are checked. - 61 - Figure 3: Water line not represented under bridges Figure 4: Unprecise creating of road centerlines Figure 5: Visual control of DTM Automated quality control was done with FME (Feature Manipulation Engine) software. Partly based on FME training and partly with help of CRONO GIP consultants in CGI the FME factory files were used for checking the structure of datasets and for checking topology. The inputs for control of dataset structure were all legal levels, colors, line styles and weights for linear elements, for point elements input there was a list of symbol (crotis.cel file) and for area elements a list of codes (representation points). FME detected all open boundaries, unused boundaries (which are not necessary for creating area topology), missing classifications points (text codes), duplicate classifications points, overlapping lines and boundaries, self intersected lines and boundaries. 2.3.3 RESULTS OF CONTROL After the control, the results were divided to: - Comments connected to undefined specification - Comments connected to misinterpretation of specification - Comments to topological processing. In the process of quality control CGI detected some cases which are not enough described or are not described in Specification. Typical example of that case is joining of road center lines. There was no rule for joining narrow paths with road center lines which are very important for creating road network topology (Figure 6). Some producers interpreted object in their own way. Typical example is representing of culverts (Figure 7) Most comments connected to topology processing were in using wrong attributes for linear elements (wrong color or weight for lines and boundaries). Distribution for errors and companies is shown in Table 1. - 62 - Figure 6: Narrow path not connected to road centerline Figure 7: Different ways of representing culverts Table 1: Distribution error types for each company Error type Invalid element type Invalid line attribute Invalid boundary attribute Unused boundaries Missing classification point (textual code) Unknown classification point Excess classification points Self intersecting lines Self intersecting boundaries Invalid cells C1 C2 ● ● ● ● ● ● ● ● Company C3 C4 ● ● ● ● ● ● ● C5 ● ● ● ● C6 ● ● ● ● ● ● ● ● ● ● ● 2.3.4. REPORTS For each company CGI wrote report, which includes: - Introduction - Authority for control - List of Sources - Content of control - Findings - General and single comments - Comments connected to topologic processing - Conclusion. 3. CONCLUSION Croatian Geodetic Institute has done Data upgrade Quality Control of structure and topology processing of topographic data in short period of time. Control of accuracy and correctness of representation and classification have not been included in this process. Complete quality system should be implemented at the end of the project. - 63 - Even though complete quality system was not implemented, CGI has done quality control in part and results of control were very useful. Before completing the specification, some elements will be changed and enhanced and the difference between producers reduced to accepted level. There is also a team in CGI for all tasks and challenges. This test quality control confirmed that contention. REFERENCES Croatian Parliament, 1999, Law of state survey and real estate cadastre, Narodne novine br. 128/99, Zagreb. Statens Kartverk, 2001. Terms of reference for the implementation of component b) and c) of the Norwegian assisted Project in Croatia for enhancing the capabilities of the Croatian Government to build a National Spatial Data Infrastructure. Appendix A to the Contract, Oslo, Norway. Program Management and Mapping, 2002. CRONO GIP Croatian Norwegian GeoInformation Project Inception study report, Zagreb, Croatia. Program Management and Mapping, 2002. CRONO GIP Croatian Norwegian GeoInformation Project – Data Inventory report, Zagreb, Croatia. Program Management and Mapping (PMM), 2003. CRONO GIP Croatian Norwegian GeoInformation Project – Data upgrade specification, Zagreb, Croatia. International Organization for Standardization, 2001, ISO/DIS 19113 Geographic information – Quality principles. International Organization for Standardization, 2002, ISO/DIS 19114 Geographic information – Quality evaluation procedures. State Geodetic Administration, 2001, Book of Ordinances, Zagreb, Narodne novine br. 55/2001, Zagreb. State Geodetic Administration, 2002, Croatian Topographic Information System CROTIS, Zagreb. - 64 - CREATING THE TOPONYMIC DATABASE OF THE REPUBLIC OF CROATIA – PROJECT TOPONIMIS AS SUB-PROJECT OF STOKIS* Stanislav Frangeš, Mladen Rapaić ABSTRACT Geographic names exist in our environment helping us to locate, define, describe and distinguish various geographic objects. They are dependent and connected to the cultural and political influences and are continuously changed and accommodated. The collection, notification and storage of geographic names have been usual tasks in map preparation for the centuries. Nowadays, maps became one of the main sources and on the other side, one of the main medias for publishing country toponyms. Although, the responsibility in creation of the official maps and topographic databases belongs to the geodesists, toponymy itself must be treated multidisciplinary. State Geodetic Administration and Croatian Geodetic Institute of the Republic of Croatia are in stage of starting the second phase of TOPONIMIS project which will prepare all necessary preconditions for creation of the national toponymc database. KEYWORDS: Toponyms, Toponymic database, Topographic database, TOPONIMIS, STOKIS, CROTIS, UNGEGN 1. INTRODUCTION The United Nations Group of Experts on Geographic Names (UNGEGN) was founded according to the resolutions of the Economic and Social Council (ECOSOC) for the purpose of solving the problems referring to the names of states and cities in documents issued by various bodies of the United Nations. The basic principle is contained in the intention to rely on standardisation of geographical names on their national standardisations. Many living and inanimate objects have their names that are mutually distinguished, so their introduction into map make the cartographic presentation more informative. The names of general geographic or topographic objects - toponymes are divided into: - Conduct fundamental geodetic worksOronymes or the names of single relief features on the Earth - Hydronymes or the names of waters - Regionymes or the names of fields, meadows, pastures, orchards, vineyards and forests and of larger geographic units - Econymes or the names of settlements - Hodonymes or the names of traffic routes - Territorionymes or the names of single areas under the authority of some state or other territorial units (Lovrić 1988). 2. EXPERIENCES FROM ABROAD In most of the countries, adequate institutions deal with content and lexical issues related to geographic names working on their standardisation: Permanent Committee for Geographic Names (Ständiger Ausschuss für Geographische Namen) in Germany, Working Group for Cartographic Toponymy (Arbeitsgemeinschaft für topographische Ortsnamenkunde) in Austria, Committee for Geographic Names in Denmark, Permanent Committee for the Standardisation of Geographic Names within the frame of Royal Geographic Society in Great Britain, Commission for the Standardisation of Geographic Names in Slovenia and others. It is not just important but essential that those institutions have been established by the legal action (law, order, directive) by their state Government and have legal authority to run the project. UNGEGN published the manual which gave essential recommendations for establishing such bodies. According to that manual (Orth, 1990), the establishment of country names * Predstavljeno na International Society for Photogrammetry and Remote Sensing (ISPRS) WG VI/3 Workshop-u: "GeoInformation for Practice", održanom u Zagrebu 15.-18.10.2003. godine. Objavljeno u zborniku radova (Frangeš, S., Rapaić, M.: Creating the toponymic database of the Republic of Croatia – Project Toponimis as sub-project of Stokis. Proceedings of the International Society for Photogrammetry and Remote Sensing (ISPRS) WG VI/3 Workshop: "GeoInformation for Practice", 15-18 October 2003, ISSN 1682-1750, Zagreb, Croatia). - 65 - authority have, among others, two main reasons: it guarantees continuing status of the work and it clearly states commission, powers, privileges and areas of responsibility. At the meetings of the United Nations Group of Experts on Geographic Names it has been urged from the member states to publish standardised geographic lists (Croatia has got only the List of Settlements of the Republic of Croatia so far published by the State Institute for Statistics) that would make the work easier for cartographers and other publishers. This Group recommends that the lists should contain the data about the type of an objects that the name refers to, exact positional description and expansion area, map sheet name where it is placed etc. Since the publication of such lists is very expensive and the data are not updated, it is recommended for toponymic database to be produced in digital form. Dissemination of toponymic database is final and crucial step and it justifies all efforts and money invested into the work of geographic name authorities. The evolution of Internet gave opportunity to publish the database and all related documents in easiest possible way and to the world-wide audience. Good and encouraging examples are the Gazetteers of Canada (Natural Resources Canada), Estonia (Institute of the Estonian Language), United States (United States Geological Survey) and United Kingdom (PCGN). 3. SITUATION IN THE REPUBLIC OF CROATIA So far, the Republic of Croatia has got no authority constituted at the official, state level that would deal with Croatian and international geographic names in systematic and organised way. The competencies for changing the names of administrative units are regulated by the laws. Thus, the House of Representatives in the Croatian National Parliament makes the decisions referring to the areas of counties, cities and municipalities (name, area and the residence of the county, city and municipality), and the county assemblies are responsible for giving names and making decisions about names and borders of settlements areas. Borders and names are kept in the Register of Spatial Units in the State Geodetic Administration. The users of geographical names have great problems already in using the names of settlements in the Republic of Croatia because of frequent changes in recent years and because of printing and other mistakes in official documents. The problems (inconsistency, incorrectness, uncertainty) also appear in using the names of other states and in using our traditional names of foreign geographic features (e. g. Kopenhagen – København). Geographic names have great significance for each country and nation since they reflect landscape, express national identity and are cultural heritage. They are used in all aspects of society, from production of geodetic plans and topographic maps, publication activity, education and urban planning, to environmental protection, tourism, economy, foreign affairs etc., therefore, it is necessary to pay larger attention and to organize the collaboration of various professions. Since the problem of correct usage of foreign and homeland geographic names is present in state official documents, cadastral plans, topographic and other maps, encyclopedias, school and other atlases, on the radio, television, internet and in the newspapers it is necessary to work on the standardisation of national and international geographic names, on the production of toponymic guides, national geographic register, abbreviated geographic register etc. (Buljat 1997). According to Official Topographic and Cartographic Information System - STOKIS (State Geodetic Administration 1995) an object can have more names that are distinguished by the type. Three types of names are foreseen: - Geographic names, generally used object name - Second name, folk or tourist description existing along with the geographic name - Classification name, abbreviations, numerical signs etc. According to Topographic Information System of the Republic of Croatia - CROTIS (State Geodetic Administration 2000) the toponymes present an object entity classified into the following groups and then subgroups: - Regionymes o area (region), field, lawn - Oronymes o mountain, mountain-range, foothills o pass, valley, cliff, gorge, crest, slope o pick, saddle, rock - Hydronyms o bay, cove, cape o sea region - Names of islands - 66 - o o Islands rock, crest, sea shallow. 3.1. PROJECT TOPONIMIS, THE FIRST PHASE The entire project TOPONIMIS, as sub-project of STOKIS is therefore intended for creating an adequate toponymic digital database that would contain geographic names adjusted to: - Accelerated production of all maps and maps of related presentations, with an accent on official cartographic publications - Consequent and correct usage of geographic names for official cartographic publications - Various GIS users of spatial data - Official usage. The first phase is planned for: - Creation of an adequate information subsystem that would encompass all geographic names according to the defined logical structure that in any way appears in official usage of state maps, - Categorisation of toponyms in accordance with the STOKIS and CROTIS, - The establishment of contacts between adequate institutions (State Geodetic Administration, Croatian Geodetic Institute, Croatian Academy of Sciences and Arts, Croatian School Cartography, Croatian State Archives, Croatian Hydrographic Institute, Lexicographic Institute "Miroslav Krleža" etc.) and professionals. Within the scope of the project TOPONIMIS, the research has been carried out that led to the working version of an establishment concept for the information system that would encompass all geographic names according to the defined logical structure that in some way appear in official usage on state maps. It includes the following names: - Settlements (towns, part of towns – districts, villages) supplemented by the names of hamlets and categorised according to defined criteria, - Geographic entities (areas, lawns, islands, peninsulas, capes etc.) - Those connected with hydrography (sea, bays, inlets, harbours, ports, shallow waters, lakes, rivers, streams, canals, swamps etc.) - Those connected with relief (massif, mountains, mountain-ranges, foothills, passes, valleys, cliffs, crests, peaks, rocks, caves, steep rocks, etc.) - Those connected with political, administrative and statistical classification (names of neighboring countries, counties, cities, municipalities, settlements, cadastral municipalities, etc.) (State Geodetic Administration 2002). 3.2. CONTINUATION OF THE PROJECT In the second phase of the project it is planned to do the following: - The active involvement of adequate institutions and professionals who are directly of indirectly connected to the project - Establishment of official contact with United Nations Group of Expert on Geographical Names - Gathering relevant information and experiences from other countries - Gathering relevant information from various users of future toponymic database - Creation of database concept and technological environment for realisation of next phase. The third phase would be the phase of implementation, with following tasks: - Entering the data gathered in the process of producing new digital Croatian Base Map (HOK) and the Topographic database into toponymic database - Entering the data gathered in the preparation for printing HOK into toponymic database - Controlling by adequate state institutions - Defining the procedures for maintaining the toponymic database. Along with realization of TOPONIMIS project, the parallel process of establishment the governmental body responsible for the standardization of geographical names have to be conducted. All participants in project, led by the State Geodetic Administration, should put effort in arising the awareness in the whole community for necessity of that decision. It can be even stated that all invested time and money will be in vain if no standardization body will not exist to approve, maintain and overtake the responsibility. 4. TOPONYMIC DATABASE In this early stage of preparing the start of future project, general idea of toponymic database exist in form of ideas, professional discussions, wishes and knowledge of realised databases in other - 67 - countries. One fact is certain and that's the name of the institution that will run the database. Croatian Law of State Survey and Real Estate Cadastre strictly defines in the Article 44 that Croatian Geodetic Institute "establishes and kept the register of geographical names" (State Geodetic Administration, 1999) which give to the Institute not just right, but obligation to conduct and run preparation of this task. Source The ongoing project CRONO GIP (Croatian Norwegian GeoInformation Project) has several components (sub-projects) and one of them is establishment of the Topographic database in the State Geodetic Administration (SGA) of Croatia related to production of Topographic map 1:25000. According to project documentation (State Geodetic Administration, 2001), geographic names exist in that database in two forms: firstly, as stand-alone objects in separate Feature category, not related or connected to any specific topographic object and secondly, as attributes of existing topographic objects. The main sources for collecting and storing toponyms in the SGA's Topographic database are existing and official Topographic map 1:25000 (TK25), existing official gazetteers (e.g. for settlement names) and field checking. This database will be the starting point and the main source for toponymic database. The reasons are more than obvious: professionally correct and accurate data, data stored in organized, modern and documented way and very strong economic reason: using existing data with investment only in additional and necessary procedures (standardisation, attribution, linkage with other databases and other that will be defined in the future). During developing phase of CRONO GIP project, some of the existing digital data already created in previous production of TK25 have been examined and for testing purposes prepared for uploading into the Topographic database. Following figures presents in graphical way position of names of the settlements (Figure 1), names of the geographic entities (Figure 2), the hydrographic names (Figure 3) and the relief names (Figure 4) on the same area. Figure 1: Settlement names Figure 2: Geographic area names Figure 3: Hydrographic names Figure 4: Relief names Figure 5 presents dispersion of all toponyms along the same area, the area that is covered by one map sheet – Pićan, in scale 1:25000. - 68 - Figure 5: All toponyms Number of toponyms divided into four categories (A - names of the settlements, B - names of the geographic entities, C - hydrographic names, D - relief names) on six various map sheets are presented in Table 1. Map name A B C D Nin 38 38 28 24 Murvica 75 62 6 65 Škabrnja 64 100 48 41 Pićan 229 34 18 60 Kupljenovo 70 60 38 20 Rasinja 0 58 17 33 Table 1. number of toponyms on various maps TK25 Database concept Technical details among which is the database design, are not yet defined and are directly connected to desired level of usability and possibility for multiple users of multiple disciplines to use it. One of the main questions that will have to be answered will be repetitivity of the same toponym: will there be just one to one relations between object and it's name or one-to-many relations, where for one object more repetitions (because of positioning on various map sheets) of the same toponym will be allowed. Investigation of other country's experiences and exact examples is still in process by the staff of the Croatian Geodetic Institute. The establishment of contact with the United Nations Group of Expert on Geographical Names (UNGEGN) and it's Working Group on Toponymic Data Files and Gazetteers is essential part in this preparation process. Number of attributes that describes toponyms vary from country to country. At this point, it can be said that mandatory attributes that should be connected to each record in the Croatian toponymic database will be: - Type/category/class of topographic object to which toponym belongs, according to the Topographic database documentation - Identification number of topographic object for connection with the SGA's Topographic database - Identification number of the toponym - Source from which toponym is put into the Topographic database - Vintage of the source - Coordinates of the principal point of the toponym. Toponymic project will have to determine definition of the principal point for each topographic feature - Descriptive position, which can be either name and/or nomenclature of map sheet of certain scale, municipality name or other local administrative unit's name. The quality of toponymic database will arise if more attributes could be added. Some of the attributes that can be put in database are: - Variant name, which can be the same toponym written in other form or in other language - Cartographic name, variant of toponym used on a map (for example abbreviated name) - Status of standardisation of toponym, (for example officially approved, historic, etc.) - 69 - Coordinates that define position of the topographic object, (for example, minimum and maximum coordinate values) - Numerical value (for example number of inhabitants or mountain height) - Link to the superior topographic object of the same topographic feature category (for example, mountain peak linked to mountain, mountain linked to mountain chain) - Identification number of toponym or topographic object from gazetteer that was source for toponym. Number of additional attributes can be even larger, but optimum level will be defined after thorough optimisation of expected expenses related to expected data quality. - 5. CONCLUSION The production of a comprehensive register of geographic names is an extensive, but necessary and still not initiated work that the Croatian official geodesy is to be faced with. With regard to the importance, extensiveness and significance of producing an adequate toponymic database it is indispensable to establish the collaboration on a wide level that would include geodesists, geographers, cartographers, linguists, historians and others. Although creation of toponymic database is important and is tremendous effort, without establishment of official governmental body that will be responsible for the content and maintaining of database, results of those efforts will not be fully accepted among users and by time can be overridden by other unformal, unofficial and unreliable gazetteers. Along with establishment of principles and procedures for using and creating toponyms on official, Croatian language, the care has to be taken also to the minority languages, narrative names and to non-Croatian toponyms, the way that toponyms are used in languages of neighboring languages. REFERENCES Buljat, J., 1997. Međunarodne aktivnosti normizacije geografskog nazivlja, Geodetski list, 2, pp. 158161. Orth, D.J., 1990. “Organization and functions of a National Geographical Names Standardization Programme: A Manual.”, World Cartography, Vol. XXI, New York, United Nations, pp. 11-40. Lovrić, P., 1988. Opća kartografija, Liber, Zagreb. State Geodetic Administration, 1995. Službeni topografsko-kartografski informacijski sustav – Idejni projekt, Zavod za fotogrametriju d.d., Zagreb. State Geodetic Administration, 1999. Law of state survey and real estate cadastre, Narodne novine br. 128/99, Zagreb State Geodetic Administration, 2000. Topografsko informacijski sustav Republike Hrvatske – CROTIS, Temeljna načela – Katalog objekata, verzija 1.0, GEOFOTO d.o.o., Zagreb. State Geodetic Administration, 2001. Object Catalogue, version 1.1, Croatian Topographic Information System - CROTIS, Zagreb, Croatia State Geodetic Administration, 2002. Projekt Toponimika – nazivlje, I. faza, Sveučilište u Zagrebu – Geodetski fakultet – Zavod za kartografiju, Zagreb. Natural Resources Canada, Canadian Geographical Names, http://geonames.nrcan.gc.ca/index_e.php, (accessed 20 May 2003), Institute of the Estonian Language, http://www.eki.ee/knab/knab.htm, (accessed 20 May 2003), United States Geological Survey, Geographic Names Information System, http://geonames.usgs.gov/, (accessed 20 May 2003), PCGN: The Permanent Committee on Geographical Names for British Official Use, http://www.pcgn.org. uk/Indexx.htm, (accessed 20 May 2003) - 70 - SPECIFIČNOSTI GEODETSKE OSNOVE U TUNELOGRADNJI* Ilija Grgić SAŽETAK U ovome istraživanju željelo se pokazati da li primjena GPS-a u tunelogradnji može u potpunosti zamijeniti do sada primjenjivane načine razvijanja mreža, bez nužnosti izvođenja terestričkih mjerenja, a da se pri tom jamči proboj tunela u okviru dozvoljenih odstupanja. Dalje se željela izvršiti usporedba točnosti proboja tunela ukoliko su koordinate mikromreža određene GPS tehnologijom u odnosu na mikromreže koje su određene terestričkim mjerenjima. Radnja obuhvaća razvijanje mikromreža u tunelogradnji na nepristupačnim terenima kada je nemoguće, ili teško moguće ostvariti vezu mikromreža terestričkim mjerenjima razvijanjem lanaca trokuta ili četverokuta (miniranost terena), načine opažanja, izvore pogrešaka, te analizu i interpretaciju konkretnih rezultata dobivenih tijekom rada na projektu tunela “Sveti Rok”. Nadzemnu geodetsku osnovu čine dvije samostalne mreže koje povezuje precizni poligonski vlak preko Velebita. Podzemnu geodetsku osnovu čine dva slobodno vođena poligonska vlaka duž jedne i druge strane tunela, s time da je izvršena stabilizacija samo za jedan slobodni poligonski vlak duž jedne strane. Obavljene su različite vrste izjednačenja: GPS mjerenja, triangulacije i trilateracije za obadvije mreže, kao i kombinirano izjednačenje s preciznim poligonskim vlakom. U svim izjednačenjima terestričkih mjerenja korišten je Gauss-Markovljev model posrednih mjerenja uz načelo najmanjih kvadrata. ZUSAMMENFASSUNG Das Ziel dieser Forschung war zu zeigen ob die bis jetzt angewendeten Methoden der Netzentwicklungen im Tunnelbau durch die Anwendung des Globalen Positionierungssystems GPS erfolgreich ersetzt werden kann, ohne terrestrische Messungen durchführen zu muβen, daβ dabei der Durchschlag des Tunnels gewährleistet wird. Das weitere Ziel war die Durchschlagsgenauigkeiten des Tunnels zu vergleichen abhängig davon ob die Koordinaten des Netzes mittels GPS Messmethoden bestimmt worden sind im Bezug zu den Koordinaten des Netzes die mittels terrestrischen Messungen bestimmt worden sind. Diese Magisterarbeit erfaβt die Netzentwicklungen in dem Tunnelbau auf den unzugänglichen Gebieten, wenn es unmöglich oder bedingt möglich ist die Verbindung der Auβennetze durch die Entwicklung der Dreiecks- bzw. Vierecksketten zu verwirklichen (durch die Mienen verseuchtes Gebiet), die Beobactungsmethoden, die Fehlerquellen und die Analise und die Interpretation der konkreten Ergebnisse, die durch die Bearbeitung der durchgeführten Messungen aus dem Projekt des Tunnels «Sveti Rok» hervorgekommen sind. Das überirdische Vermessungsnetz bilden zwei freien Netze, die ein präziser Polygonzug über Velebit verbindet. Das unterirdische Vermessungsnetz bilden zwei freigeführten Polygonzüge entlang der beiden Tunnelseiten, wobei die Vermarkung nur für ein freigeführter Poligonzug gemacht worden ist. Es sind unterschiedliche Arten der Ausgleichung durchgeführt worden: die Ausgleichung der GPS Messsungen, die Ausgleichung der Richtungs- und der Streckenmessungen der beiden Netzen, sowohl die Ausgleichung des kombiniertes Netzes mit dem präzisen Polygonzug über Velebit. In allen Ausgleichungen der terrestrische Messungen ist der GauβMarkoff-Modell der vermittelten Messungen mit der Methode der kleinsten Quadrate angewendet worden. * Magistarski rad obranjen na Geodetskom fakultetu Sveučilišta u Zagrebu 14.11.2003. godine. - 71 - - 72 - CHANGES OF BENCH MARK HEIGHTS BEING THE CONSEQUENCE OF INTRODUCING THE NEW CROATIAN HEIGHT SYSTEM* Nevio Rožić ABSTRACT In the period between 1994-2002 there were rather extensive works carried out in the Republic of Croatia on the improvement of national levelling networks and the height system based on the existing (archive) data of geometric levelling measurements. The results of these works are the basis for introducing the improved (new) Croatian height system into official usage. The differences in definition and realisation between the improved (new) and existing (old) Croatian height system are, among other things, directly reflected on the changes of national levelling bench mark heights. On the basis of the bench mark heights comparison it is possible to define and analyse the level of mutual disparity and distortion of height systems. For this purpose, the bench mark heights in the national geometric levelling networks have been analysed, as very indicative, in the northern part of the territory of the Republic of Croatia. 1. INTRODUCTION The systematic works on the improvement of the existing height system, that was initially defined and realised in the period 1875-1914 as Croatia was the integral part of the Austro-Hungarian Monarchy and that was additionally updated and modernised with numerous new works on geometric levelling of various orders in the period 1945-1970 as Croatia being the part of former Yugoslavia, started during the year 1994 and were completed by the end of 2002. The stated systematic works were based on the repeated computing processing of the existing (archive) data referring to the levelling network measurements, considering the objective and material circumstances that the Republic of Croatia found itself in at the beginning of the nineties after gaining its independence, with introduction of the "new" fundamental height network, as well as the new height datum. The network of the so-called II. levelling of the high accuracy (IINVT) that had been made at the territory of the western part of former Yugoslavia in the period 1970-1973, leaning on five tide gauges along the Adriatic coast (Koper, Rovinj, Bakar, Split and Dubrovnik), was introduced as the "new" fundamental height network at state territory. Due to some objective circumstances, i.e. very long period of analysis and data processing, network was not used until 1992. The detailed data about the previously mentioned works on the improvement of the height system in Croatia can be found in the reports and articles presented at EUREF symposia in previous years Feil et al. 1992, Feil et al. 1993, Klak et al. 1996, Rožić et al. 2000, Rožić 2003, and the informations about various aspects and problems connected with the national levelling networks and the height system at the territory of Croatia can additionally be found in Feil et al. 1999, Feil et al. 1999a, Rožić 1999, Rožić 2001. Considering the fact that there is the process of putting of the new height system into the official usage going on at the moment, the issue of investigation the congruence level, i.e. the differences between the bench mark heights included into national geometric levelling networks is being raised as a very interesting issue. The differences between the height systems and their influence on bench marks heights, in the geometric levelling networks at the northern part of the Republic of Croatia, are very indicative and usable for that purpose. 2. OLD HEIGHT SYSTEM The old height system (at the moment still the official height system) of the Republic of Croatia was established during the time of the Austro-Hungarian Monarchy as a normal orthometric height system, and it was realized through the network of the so called Austrian Precise Levelling (APN). The origin bench mark in the system was the bench mark HM 1 placed in the vicinity of the tide gauge at Molo Sartorio in Trieste. It absolute height is defined in relation to the mean value of the Adriatic Sea water level obtained from the one-year measurements in 1875, and it is 3.3520 m. After the Second World War, referring to about forty years that passed after the establishment and the realisation of APN Predstavljeno na EUREF2004 simpoziju (Symposium of the IAG Subcommission for Europe – EUREF) održanom u Bratislavi, Slovačka, 2.-5.6.2004. godine. Objavljeno u Zborniku radova Simpozija (u tisku). * - 73 - network, and considering a great number of destroyed bench marks, the network was reconstructed through an extensive new bench mark stabilisation and through the repeated levelling of levelling lines within the frame of performing the so called I. levelling of high accuracy (INVT) of former Yugoslavia. In the realisation of the INVT network some discrepancies occurred relating to the geometric configuration of the APN network, first of all for the purpose of eliminating a few longer levelling lines in Dalmatia and defining geometrically closed and firm figures. The measurements of INVT were made gradually and in a longer period of time, from 1945 till 1963, and the determination of bench mark heights (measurement adjustments) were made successively and in accordance with the survey dynamics, whereby the new measurements were adjusted on the old (preserved) APN network bench marks, Fig. 1. 47° 47° AUSTRIJA ITALIJA 321 14 5 122a 122 Rovinj 20242 Pula 122 MVIII MLVIII IV III HM504 I 13 II 23 41/13 271 CMXVI 5696 Čakovec 271 VI 272 266 273 274 306 IX 4/307 Otočac DCCLIII VII 2900 2797 MLII Oštarije 1727 Virovitica 265 263 X 264 3339 Kostajnica 304 3165 Drežnik 280 BV11378 3387 3317 307 XIV 302 1/318 Sv.Rok 318 BV15881 XVIII MCCCXXII Knin 317 XVII MCCCXCV 3467 283 XII 278 BV12720 BV12554 284 MCLXVIII 0 285 XX 291 315 508 XIX 110/286 I. NIVELMAN VISOKE TOČNOSTI XVI 449 286 REPUBLIKA HRVATSKA 281 282 BV13338 MCCCXCI Sinj 276 277 XV 485 292 MCCC Split 261 2045 262 Sl.Brod BV11377 Vinkovci 279 301 300 248 BV10745 Borovo 252 VIII BiH MCDLXXXIV XIII 298 BV13025 DCCXXVIII BV10650 Osijek Dalj 198 XI 280 304 305 MAĐARSKA 266 MDL 259 BV11631 Zagreb V 275 320 2203 Rijeka 322 3597 SLOVENIJA 7 MCCCLVIII MDX HM404 11 68/284 317 XXI 316 DCLXXVIII 95/318 289 XXII 318 84/317 10 20 30 40 50 km Tumač znakova: čvorni reper mareograf nivelmanski vlak br. nivel. vlaka 295 293 4/297 Dubrovnik DCLXVI DCXXXXVII 296 Geodetski Fakultet Sveučilišta u Zagrebu 42° 42° 13° 23° Fig. 1. INVT levelling network at the territory of the Republic of Croatia Along with the realization of the INVT network, there were also many levelling works on lower order geometric levelling networks made (precise levelling - PN, city levellings - GN, technical levelling of increased accuracy - TNPT, technical levelling - TN) that cover relatively regularly the whole state territory. The adjustments of measurements in the lower order geometric levelling networks was made in a hierarchical order by lower order levellings leaning on higher order levelling networks, by applying the condition measurements adjustment using the method of least squares. It should be pointed out that in terms of accuracy the measurements were partly inhomogeneous, and in terms of hierarchic data processing the adjustments of more complex networks were avoided by simplifying their geometric configurations. The quantity of the performed works is expressed by the number of 423 levelling lines at the entire territory of the Republic of Croatia, i.e. in accordance with the classification into the accuracy orders: 36 INVT levelling lines, 77 precise levelling lines, 49 city levelling lines (networks), 149 increased accuracy technical levelling lines and 112 technical levelling lines. 3. NEW HEIGHT SYSTEM In the period 1970-1973, a new high accuracy levelling network was made at the western part of former Yugoslavia, i.e. the network of so called II levelling of high accuracy (IINVT) that should have been used as the basis for the establishment of the new height system. The new height system should have removed the weakness of the existing system, which means that it should have been updated, it should have had adequate accuracy and removed the error in determining the origin bench mark height (bench mark HM1) in the old height system. The geometric configuration of the IINVT network is therefore designed and performed mostly in disparity with the existing INVT network, and the IINVT network is at the same time connected with five tide gauges at the Adriatic coast (Koper, Rovinj, Bakar, - 74 - Split and Dubrovnik), Fig. 2. The absolute heights of the 5 new origin bench marks in the IINVT network were determined at all tide gauges in relation to mean water levels of the Adriatic Sea for the time epoch of 1971.5, from the measurement interval of 18.6 years. 47° 47° AUSTRIJA HM404 C907 C16 ITALIJA PN305 FR3052 II 2753 7 8 SLOVENIJA BP82 Rovinj I 2 12 III FR1029 Brajkovići BV MCXVII Bakar 11 10 C46 Senj 21 9 IV A437 Novska CP695 Kostajnica 22 MCCI Ž.Lokva 51 16 FR3020 Zagreb 64 5 1 FR3116 15 MCDLV A56 14 FR3053 Varaždin 6 5486 Koper MAĐARSKA 13 65 17 C143 Pčelić DCCLIII Virovitica 41 18 BV11530 19 Daruvar VIII 37 C650 Okučani O362 Batina 45 46 CP317 Osijek 48 K274 43 Našice 38 36 VII 39 XI V XII FR1065 49 40 OP477 VI FR1069 32 REPUBLIKA HRVATSKA C694 XIII 28 25 47 50 27 FR3119 54 FR3102 BiH 53 C880 FR3063 O472 26 IX X Strizivojna FR1039 24 FR3118 44 42 20 23 52 FR3114 II. NIVELMAN VISOKE TOČNOSTI 55 FR1067 33 29 A473 FR1085 0 C162 Šibenik 31 3 XIV BV14530 MCCC Split PN167 30 56 34 20 30 40 50 km Tumač znakova: A377 35 10 57 reper XV 58 čvorni reper 61 C346 Opuzen mareograf FR1089 XVI nivelmanski vlak br. nivel. vlaka 63 FR1098 4 C620 Dubrovnik A496 59 Geodetski Fakultet Sveučilišta u Zagrebu 62 60 FR1094 42° 13° 42° 23° Fig. 2. IINVT levelling network at the territory of the Republic of Croatia Referring to the fact that along the levelling lines in the IINVT network the gravimetric measurements have not been carried out completely and systematically, and that the measuring data processing and analysis was carried out during a very long period, i.e. between 1973 and 1992, it full implementation was not enabled till beginning of the nineties within the frame of the realisation of the new normal-orthometric height system to be practically used at the territory of the Republic of Croatia. In the period between 1994 and 2002, all existing low order geometric levelling networks were connected to this network, and in parallel with field revision of bench marks included into these networks, there was a complete and systematic computation and systematic processing of original measuring data made, i.e. the new network adjustments (readjustments). The measurements were adjusted consistently by indirect measurements adjustments using the least squares method and keeping the hierarchical order of processing, i.e. leaning the lower order geometric levelling networks to higher order networks, and in accordance with the pre-systematized geometric configurations of the networks without their simplification in spite of the complexity. With reference to the works done, a new and updated applicable documentation was made for all preserved bench marks of levelling networks, including the sketches of levelling networks and figures, positional descriptions, positional bench mark coordinates in the state coordinate systems, heights etc. 4. RELATIONSHIP OF BENCH MARK HEIGHTS IN THE NORTHERN PART OF CROATIA Referring to the fact that the old and the new height system of the Republic of Croatia are normal-orthometric systems realized at the same territory, to a great extent on the basis of the same measurement data, i.e. the same geometric levelling networks, they can be compared between each other. The most interesting is the comparison of the heights of all bench marks that are present in both systems at the same time, because it indicates congruity level of both systems, the size and regularity of difference distribution in heights and its influence on performing the practical works that require the knowledge of the heights. Considering the way of defining and establishing the height systems, it is clear that the differences in bench mark heights result from the mutual influence of a few various reasons: - the difference in number, procedure and time epoch of determining the origin bench marks heights (height datum) in the fundamental height networks, and in their position as related to the - 75 - geometry of these networks. In the case of INVT it is HM1 in Trieste (the epoch of the year 1875 - the mean of one-year see level measurements), Fig. 1, and in the case of IINVT these are the bench marks 5486 - Kopar, BP82 - Rovinj, BV - Bakar, PN167 - Split and A496 – Dubrovnik located at the five tide gauges (the epoch of the year 1971,5 - the see level mean from the interval of 18,6 years), Fig. 2. the difference of geometric configurations in the fundamental height networks, i.e. INVT and IINVT, as well as difference of the used adjustment methods for these networks, Fig. 3. In the case of INVT the individual levelling lines and the parts of the network have been adjusted separately referring to the fixed base (preserved bench marks) of the network APN, and the network IINVT has been adjusted as the homogeneous network using indirect measurements and the method of least squares. - 47° 47° ITALIJA AUSTRIJA MAĐARSKA SLOVENIJA BiH REPUBLIKA HRVATSKA II NVT i I NVT 0 10 20 30 40 50 km Tumač znakova: II NVT I NVT Geodetski Fakultet Sveučilišta u Zagrebu 42° 42° 13° 23° Fig. 3. Relation of the networks INVT and IINVT at the territory of Croatia - - the difference of geometric configurations and adjustment procedures (methods) in adjusting the networks of lower order geometric levellings being the consequence of their re-systematization conditioned by the change of geometric configurations in fundamental networks that they are connected to, i.e. INVT and IINVT. influence of height instability of bench marks contained in the measuring data, referring to the fact that works on geometric levellings have been carried out in essentially different time epochs, i.e. the network APN in the period 1875-1914, the network INVT in the period 1945-1963, the network IINVT in the period 1970-1973 and the networks of lower order geometric levellings in the period 1945-1970. The size, distribution and changes of the bench mark heights between the old and the new height system should be considered in the northern part of the Republic of Croatia determined by the II. and III. levelling figure of the IINVT network, Fig. 2. The mentioned area bordered by the state border of the Republic of Croatia with the Republic Hungary and the Republic Slovenia, as well as with the IINVT levelling lines: No. 8 (Dobova – Zagreb), No. 21 (Zagreb – Kostajnica), No. 20 (Kostajnica – Novska), No. 19 (Novska – Daruvar), No. 18 (Daruvar – Pčelić), No. 17 (Pčelić – Virovitica) and No. 74 (Virovitica – Terezino polje), contains altogether 2105 bench marks, Fig. 4., with: 182 IINVT bench marks (red), 108 INVT bench marks (violet), 274 PN bench marks (brown), 863 GN bench marks (blue), 416 TNPT bench marks (green) and 262 TN bench marks (black). The concentration of bench marks and their horizontal distribution referring to the entire territory of the Republic of Croatia is presented on Fig. 5. - 76 - 5150000 5140000 5100000 5050000 5120000 5000000 5100000 4950000 5080000 4900000 5060000 4850000 5040000 4800000 4750000 5020000 4700000 2440000 2460000 2480000 2500000 2520000 2540000 2560000 2580000 Fig. 4. Bench marks 2300000 2350000 2400000 2450000 2500000 2550000 2600000 2650000 2700000 Fig. 5. Bench marks at territory of Croatia The differences of bench mark heights dH at the observed territory Rožić 2003a obtained by subtracting the bench mark height in the new height system from the belonging value in the old height system have got the value between minimum 122.6 mm and maximum 250.2 mm, and they are all contained in the interval sized 127.6 mm. The statistic indicators describing their properties, as well as the properties of bench mark coordinates in the horizontal projection plane (Yn, Xn) are shown in the table 1. Table 1. Statistical indicators Size Yn Xn dH Minimum 2431761 m 5004864 m 122.6 mm Medium 2489510 m 5076343 m 171.1 mm Maximum 2580206 m 5153316 m 250.2 mm Interval 148445 m 148452 m 127.6 mm Average 2493728 m 5082973 m 174.6 mm Variance 1227780389 m2 956324519 m2 537.9 mm2 Stand. error 35040 m 30924 m 23.2 mm The behaviour of the differences of heights at the arbitrarily selected discrete points at the entire observed territory defined on the basis of the dependence on their values at bench mark positions is graphically presented by the continuous spatial surface modelled by applying the method of "krigging" and the additional filtering. The spatial surface shape, the mutual relation between the surface and the bench mark positions are presented on Fig. 6. It should be pointed out that the shape of the surface outside the area borders is rather instable because it has been determined by means of data extrapolation. Fig. 6. Relation between the spatial surface and bench marks - 77 - Fig. 7 presents the same surface, but orthogonally projected into the projection plane and supplemented with contour lines. Fig. 7. Contour lines of height difference of bench marks 5. CONCLUSION On the basis of the numerical data from the table 1 and graphic presentations on Fig. 6 and 7 it is possible to make principal conclusions that describe the empirical rules of behaviour in the height difference of bench marks encompassed at the same time by the old and new height system of the Republic of Croatia. All height differences are positive, i.e. the bench mark heights in the old height system are bigger than the heights of the same bench marks in the new height system. This fact is in accordance with the results of investigation the relation of height datums in the old and new height system, i.e. with the error in determining the height of the origin bench mark (the bench mark HM1) in the network APN in the old height system for which the value has been defined to be about 12 cm Feil et al. 1992, Feil et al. 1993. It is very interesting that the minimum height difference of bench marks of 122,6 mm at the observed territory is also logically in congruence with previously cited value and shows that all official heights at the territory of the Republic of Croatia are initialy bigger than heights corresponding to correctly determined mean sea levels of the Adriatic sea at the locations of five tide gauges. At the same time mean see levels at all five tide gaugages are mutually in a very good accordance. The size of the interval where the height differences of bench marks are to be found is rather big and amounts at the observed territory up to 127,6 mm which indicates to the fact that significantly different fundamental networks, the changes of geometric configuration of the lower order networks have essentially affected the changes of heights along with various adjustment methods and procedures. The consequence of this influence is not only the difference of bench mark heights, but also their positional distribution and the pattern of changes depending on the position of bench marks in the plane coordinate system. The differences of bench mark heights show some trend regularities of changing depending on the bench mark positions in the plane, Fig. 7. This trend regularity is expressed especially in the direction north-south and much less expressed but still noticeable in the direction west-east. Certain areas of the observed territory indicate relatively high distortions. Generally speaking, the differences of bench mark heights are changing irregularly - 78 - along the observed area and rather significantly referring to their size. Considering the irregularities of changes and the size of differences in bench mark heights one can expect rather difficult determination of a model for the transformation of height data between the old and the new height system of the Republic of Croatia. REFERENCES Feil, L., Klak, S., Roić, M., Rožić, N. (1992): Beitrag zur Bestimmung der Vertikalkrustenbewegungen in Kroatien. Österreichische Zeitschrift für Vermessungswesen und Photogrammetrie, 1992, Heft 2, 95-106. Feil, L., Klak, S., Rožić, N. (1993): Nivellement von hoher genauigkeit auf dem gebiet der Republik Kroatien. Österreichische Zeitschrift für Vermessungswesen und Photogrammetrie, 1993, Heft 4, 176-182. Feil, L., Klak, S., Rožić, N., Gojčeta, B. (1999): National report of the Republic of Croatia on the high system. Mitteilungen des Bundesamtes für Kartographie und Geodäsie, Band 6, EUREF Publication No. 7/I, Frankfurt am Main, 1999, 142-148. Feil, L., Klak, S., Rožić, N., Gojčeta, B. (1999a): National report of the Republic of Croatia on the height system. Veröffentlichungen der Bayerischen Kommission für die Internationale Erdmessung der Bayerischen Akademie der Wissenschaften, Report on the Symposium of the IAG Subcommission for Europe (EUREF) held in Prague, 2-5 June 1999, München, 1999, Heft Nr. 60, 146-149. Klak, S., Feil, L., Rožić, N. (1996): Connection of height systems of Hungary and Croatia. Acta Geodaetica et Geophysica Hungarica, Budapest, 1996, Vol. 31 (1-2), 25-35. Rožić, N. (1999): Erhaltung der Reperepunkte im Österreichischen Präzisionsnivellement auf dem Gebiet der Republik Kroatien. Österreichische Zeitschrift für Vermessung & Geoinformation, 1999, Heft 4, 188-195. Rožić, N. (2001): Fundamental levelling networks and height datums at the territory of the Republic of Croatia. Acta Geodaetica et Geophysica Hungarica, Budapest, 2001, Vol. 36 (2), 231-243. Rožić, N. (2003): Accuracy of geometric levelling networks at the terrritory of Croatia. Mitteilungen des Bundesamtes für Kartographie und Geodäsie, Band 29, EUREF Publication No. 12, Frankfurt am Main, 2003, 336-340. Rožić, N. (2003a): Studija odnosa uporabnih visina repera geometrijskog nivelmana uvjetovanih razlikama službenog i prijedloga novog visinskog sustava Republike Hrvatske. Geodetski fakultet Sveučilišta u Zagrebu, Zagreb, 2003. Rožić, N., Feil, L., Pavičić, S. (2000): Review of activities on levelling works in the Republic of Croatia 1999-2000. Veröffentlichungen der Bayerischen Kommission für die Internationale Erdmessung der Bayerischen Akademie der Wissenschaften, Report on the Symposium of the IAG Subcommission for Europe (EUREF) held in Tromsø, 22-24 June 2000, München, 2000, Heft Nr. 61, 362-365. - 79 - - 80 - EUROPEAN VERTICAL REFERENCE NETWORK (EUVN) CONSIDERING CHAMP AND GRACE GRAVITY MODELS* Željko Hećimović, Bojan Barišić, Ilija Grgić ABSTRACT European Vertical Reference Network (EUVN), solution UELN95/98, is compared with early CHAMP (EIGEN-2, EIGEN-3p, TUM-1S, TUM-2Sp, ITG-CHAMP01E, ITG-CHAMP01S, ITGCHAMP01K) and GRACE (EIGEN-GRACE01S, GGM01S, GGM01C) gravity models. Besides CHAMP and GRACE models Earth Gravity Model 1996 (EGM96) and European gravimetric geoid 1997 (EGG97) are used in analysis. Comparisons are showing the main relation between EUVN datum and global datum. Among used gravity models GRACE-GGM01C is the best fitting EUVN gravity field. It has only slightly worst statistical characteristic than EGM96 model. GRACE-GGM01C model and EGM96 are used to check extreme values in EUVN network. They are compared with already published EUVNEGG97 extreme values. To judge topography gravity signal in CHAMP and GRACE gravity models, they are compared with denser field of GPS/leveling points on the local Croatian territory. 1. INTRODUCTION CHAMP and GRACE satellite missions and further GOCE mission are strongly influencing developments of geosciences in this decade. Already made CHAMP and GRACE gravity models are defining new standards in modeling gravity field of the Earth. Gravity signal that was out of sensitivity of previous satellite measurement techniques is clearly recognized. CHAMP and GRACE homogeneous, almost global high-resolution satellite gravity data are mainly going to improve long and middle wave gravity field spectrum. They are going to influence determination of vertical datum and heights networks. EUVN network is giving opportunity to compare its GPS\leveling undulations with global geoids. Wavelengths of a global geoid longer than the testing area (EUVN network) cannot be recognized, and the shortest wavelengths of global model that can be checked depend how dens and how accurate are the GPS\leveling undulations. Considering CHAMP and GRACE gravity models, distribution of GPS\leveling undulations should be global and dense enough that weakest gravity signal in model can be recognized. 2. USED DATA AND CHAMP AND GRACE GRAVITY FIELD MODELSEUVN network solution EUVNUELN95/98 (United European Leveling Network 1995/1998) is used (Ihde et al., 2002, Ihde and Sacher 2002a, Ihde and Sacher 2002b). It is related to the Normal Amsterdam’s Peil (NAP), but for islands and countries not connected to UELN, the heights are given in local system. EUVN network have 186 points, and distances between them are too big for reliable higher accuracy gravity field recovering. To have overview of gravity field concerning only EUVN network, GRACE-GGM01C model is calculated only in EUVN points. It is presented on the figure 1. Fig. 1 GRACE-GGM01C gravity model in EUVN points. Predstavljeno na EUREF2004 simpoziju (Symposium of the IAG Subcommission for Europe – EUREF) održanom u Bratislavi, Slovačka, 2.-5.6.2004. godine. Objavljeno u Zborniku radova Simpozija (u tisku). * - 81 - In the analysis are used early CHAMP and GRACE models that include also some preliminary solutions (s. table 1). Table 1. The main characteristics of used global gravity models Model Max. degree MISSION References EIGEN-2 EIGEN-3p TUM-1S TUM-2Sp 140 140 60 60 CHAMP CHAMP CHAMP CHAMP Reigber et al., 2003b Reigber et al., 2003c Földvary et al., 2003a Földvary et al., 2003b ITG-CHAMP01E 75 CHAMP Ilk K.H. et al., 2003, Mayer-Gürr, et al., 2004 ITG-CHAMP01S 70 CHAMP Ilk K.H. et al., 2003, Mayer-Gürr, et al., 2004 ITG-CHAMP01K EIGEN-GRACE01S GGM01S GGM01C EGM96 70 140 120 200 360 CHAMP GRACE GRACE GRACE Ilk K.H. et al., 2003 GFZ, 2003 Tapley et al., 2003 UTEX, 2003 Lemoine et al., 1998 3. COMPARISONS OF EUVN AND CHAMP AND GRACE GRAVITY MODELS To estimate how well CHAMP and GRACE geopotential models fit EUVN gravity field, they are compared with EUVN GPS/leveling undulations. Besides used CHAMP and GRACE models Earth Gravity Model 1996 (EGM96) and European Gravimetric Geoid 1997 (EGG97) are used. On the figures 2 and 3 differences between EUVN and EGM96 and EGG97 models are presented. Global gravity model EGM96 is developed up to degree and order 360 using also terrestrial data, and EGG97 model is regional European model that is using detail regional data. CHAMP and GRACE models are satellite models, and they do not contain higher resolution, terrestrial gravity field information. Considering in modeling used data, EGM96 and EGG97 models can be seen as referent models. Fig. 2 Differences of EUVN and EGM96. Fig. 3 Differences EGG97 and EUVN. - 82 - On the figures from 4 to 13 differences between EUVN and early CHAMP and GRACE models are shown. Local characteristic of differences can be clearly recognized, especially in CHAMP models. Fig. 4 Differences of EUVN and EIGEN-2. Fig. 5 Differences of EUVN and EIGEN-3p. Fig. 6 Differences of EUVN and TUM-1S. Fig. 7 Differences of EUVN and TUM-2Sp. - 83 - Fig. 8 Differences of EUVN and ITG-CHAMP01E. Fig. 9 Differences of EUVN and ITG-CHAMP01S. Fig. 10 Differences of EUVN and EIGEN-GRACE01K. Fig. 11 Differences of EUVN and EIGEN-GRACE01S. - 84 - Fig. 12 Differences of EUVN and GGM01S. Fig. 13 Differences of EUVN and GGM01C. The main statistical characteristics are given in table 2. GRACE models fit EUVN gravity field better than CHAMP models. That was expected considering differences in gravity field signal sensing technique using CHAMP and GRACE satellite missions (GFZ, Daimler Chrysler Aerospace and Deutsche Zentrum für Luft- und Raumfahrt 2000, Lühr et al. 2002, Neumayer et al. 2000, Reigber et al. 2001, Reigber et al. 2002, Reigber et al. 2003a, Reigber et al. 2003b, Baguio et al. 2002, JPL 2002a, JPL 2002b, Tapley and Reigber 2002, Hećimović and Bašić 2004b, Hećimović and Bašić 2004c, Hećimović and Bašić 2004d). Average values of EUVN and CHAMP and GRACE undulation differences can be seen in the first approximation as datum differences between EUVN network and global gravity models, but before datum analysis extreme values should be treated. Dissipate this problem it is significant that EUVN datum is lower than all global gravity models. Considering the quality of data used in the analysis, it can be only judged that datums differences is about 0,5 m. EGG97 datum was fitted to EUVN heights datum and that is the reason that average value is only -2 cm. Table 2. The main statistical characteristics of EUVN and CHAMP and GRACE undulations differences (186 points) MODEL Min. Max. Average St. dev. EGG97 EGM96 EIGEN-2 EIGEN-3p TUM-1S TUM-2Sp ITG-CHAMP01E ITG-CHAMP01S ITG-CHAMP01K EIGEN-GRACE01S GGM01S GGM01C [m] -1.51 -2.54 -3.87 -3.15 -3.85 -3.81 -3.34 -3.84 -3.66 -3.84 -2.76 -2.28 [m] 1.57 1.14 6.63 6.24 6.82 7.22 6.85 6.43 6.35 6.43 4.22 1.74 [m] -0.02 -0.60 -0.45 -0.47 -0.42 -0.39 -0.45 -0.47 -0.43 -0.47 -0.51 -0.64 [m] 0.36 0.46 1.61 1.34 1.60 1.60 1.38 1.42 1.47 1.42 0.93 0.55 - 85 - Among used models GRACE model GGM01C is fitting EUVN gravity field the best. It can be compared with EGM96 model that is developed up to degree 360. In Ihde et al. (2002) EUVN extreme values (> 0,5 m) are found using EGG97 model. Similar analysis is done using GRACE-GGM01C and EGM96 models. In table 3 are EUVN points with extreme differences found with EGG97 (Ihde et al. 2002), EGM96 and GRACE-GGM01C gravity models. EGG97 model detected 17 points as extreme values, EGM96 model 31 points and GRACE model GGM01C 47 points. On the figure 14 are presented EUVN points with extreme values. Table 3. EUVN points with extreme values found with EGG97 (Ihde et al. 2002), EGM96 and GRACE-GGM01C models Fig. 14 EUVN points with extreme values found with EGG97, EGM96 and GRACE-GGM01C models. - 86 - Five points are recognized as extreme values only by EGG97 and not by EGM96 and GGM01C models; that was not expected. 5. CHECKING OF CHAMP AND GRACE GRAVITY MODELS USING DENSER FIELD OF GPS/ LEVELING POINTS ON THE LOCAL CROATIAN TERRITORY EUVN network has only 186 points for the whole European territory, and the short-wave structure of gravity field can be recognized only discretely in EUVN points and not on the whole European territory. To get better view in finer structure of gravity signal sensed with CHAMP and GRACE satellite missions, 121 GPS/leveling points homogeneously distributed over the territory of Croatia are used. They are compared with CHAMP-EIGEN-3p and GRACE-GGM01C models. Differences between GPS/leveling and CHAMP-EIGEN-3p undulations are presented on the figure 15 and on figure 16 are presented differences with GRACE-GGM01C model. In table 4 are the main statistical characteristics for the both models (Hećimović and Bašić 2004a). Fig. 15 Differences between GPS/leveling undulations and undulations of CHAMP-EIGEN-3p model. Fig. 16 Differences between GPS/leveling undulations and undulations of GGM01C model. - 87 - Table 4. The main statistical characteristics of global geopotential model on the territory of Croatia (121 points) MODEL Min. Max. Average St. dev. EIGEN-3p GGM01C [m] -3.40 -2.02 [m] 1.89 0.17 [m] -1.07 -1.00 [m] 1.04 0.45 The main characteristics of the Croatian topography is that dominating higher part is spreading along the coast, and small higher part is in the middle of north-east Croatia, see figure 17. On the Croatian coast mountains are rising very speedy from sea level up to 1500 m and higher. Fig. 17 Croatian topography. Comparing figures 15, 16 and 17 correlation with topography can be recognized in CHAMP model. CHAMP undulations do not contain detail topography signal that is contained in GPS/leveling undulations. The same effect cannot be found in GRACE undulations because they contain more topography gravity signal and differences are less correlated with topography. Average values in table 4 are in the first approximation datum difference between Croatian heights system and EIGEN-3p and GGM01C global models. These values are showing agreement with previously made comparisons between Croatian height system and EGM96 and GFZ97 global gravity models (Hećimović and Bašić, 2002). Because too large distances between points the same effect cannot be recognized in EUVN network. Densification of EUVN points is necessary for regional and local improving and checking of global gravity field models. That is topics of presently running EUREF EUVN_DA project. 5. CONCLUSIONS Early CHAMP and GRACE gravity models used in comparison with EUVN network are showing that EUVN datum is lower than datums of all global gravity models. Considering the quality of data used in the analysis, it can be only judged that datums difference is about 0,5 m. GRACE models show better fitting of gravity field than CHAMP models. Among used models GRACE GGM01C model is fitting EUVN gravity field the best. It can be compared with EGM96 model that is developed up to degree 360. - 88 - The biggest number of extreme values of undulation differences is found for GGM01C, after that for EGM96 and finally for EGG97 model. That is also indicating quality relation between gravity models. That was expected considering data used in modeling. It is surprising that some extreme values are recognized only by EGG97 and not by EGM96 and GGM01C models. Comparison of 121 GPS/leveling points homogeneously distributed over the territory of Croatia and CHAMP-EIGEN-3p and GRACE-GGM01C models is indicating amount of topography gravity signal sensed in CHAMP and GRACE models. Full contribution of CHAMP and GRACE models can be expected in the future, especially models that will combine CHAMP and GRACE satellite data with terrestrial data. CHAMP is German satellite mission, GRACE USA/German and GOCE is ESA satellite mission. These satellite missions are strongly influencing development of gravity field modeling community in Europe. EUREF is fundamentally defined in domain of GNNS satellite radio navigation, but it has interest in the Earth gravity field, and this gravity field trend in Europe is going to influence EUREF. REFERENCES Baguio, M., B. Bandeen, C. Griner, M. King i M. Srinivasan (Eds.) (2002): GRACE, Gravity Recovery and Climate Experiment (GRACE) mission. NASA, Goddard Space Flight Center, Greenbelt, Maryland, NP-2002-2-427-GSFC. Földvary, L., Svehla, D., Gerlach, Ch., Wermuth, M., Gruber, T., Rumme, R., Rothacher, M., Frommknecht, B., Peters, T, Steigenberger, P. (2003a): Gravity Model TUM-2Sp Based on the Energy Balance Approach and Kinematics CHAMP Orbits; Proceedings "Second CHAMP Science Meeting", GFZ Potsdam, Sept. 1-4 (in preparation). Földvary, L., Svehla, D., Gerlach, Ch., Wermuth, M., Gruber, T., Rumme, R., Rothacher, M., Frommknecht, B., Peters, T, Steigenberger, P. (2003b): Gravity Model TUM-2Sp Based on the Energy Balance Approach and Kinematics CHAMP Orbits; Proceedings "Second CHAMP Science Meeting", GFZ Potsdam, Sept. 1-4 (in preparation) GFZ, DaimlerChrysler Aerospace i Deutsche Zentrum für Luft- und Raumfahrt a.V. (2000): CHAMP - Der Blick in das Innere der Erde. 2000. GFZ (2003): First GFZ GRACE gravity field model EIGEN-GRACE01S released on July 25, 2003. URL:http://op.gfz-potsdam.de/grace/results/grav/g001_eigen-grace01s.html Hećimović, Ž., T. Bašić (2002): Globalni geopotencijalni modeli na teritoriju Hrvatske. Geodetski list, God. 57 (80), broj 2, str. 73-89, Zagreb 2003 (in Croatian). Hećimović, Ž., T. Bašić (2004a): Comparison of CHAMP and GRACE geoid models with Croatian HRG2000 geoid. 1st General Assembly European Geosciences Union (EGU), Nice, France, from 25 - 30 April 2004. Poster presentation. Geophysical Research Abstracts, Vol. 6, 02715, 2004. SREef-D: 1607-7962/EGU04-A-02715. European Geoscience Union 2004. Hećimović, Ž., T. Bašić (2004b): CHAllenging Minisatellite Payload (CHAMP) satelitska misija. Given for publishing in Geodetski list (in Croatian). Hećimović, Ž., T. Bašić (2004c): Gravity Recovery and Climate Experiment (GRACE) satelitska misija. Given for publishing in Geodetski list (in Croatian). Hećimović, Ž., T. Bašić (2004d): Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) satelitska misija. Given for publishing in Geodetski list (in Croatian). Ihde, J., M. Sacher (Eds.) (2002a): European Vertical Reference Network (EUVN). Vol. I. Final Documentation. Mitteilungen des Bundesamtes fuer Kartographie und Geodaesie. International Association of Geodesy, Section 1 - Positioning, Commission X - Global and Regional Geodetic Networks, Sub-Commission for Europe (EUREF). Publication No. 11, Vol. I. Frankfurt am Main 2002. Ihde, J., M. Sacher (Eds.) (2002b): European Vertical Reference Network (EUVN). Vol. II. Final Documentation. Mitteilungen des Bundesamtes fuer Kartographie und Geodaesie. International Association of Geodesy, Section 1 - Positioning, Commission X - Global and Regional Geodetic Networks, Sub-Commission for Europe (EUREF). Publication No. 11, Vol. I. Frankfurt am Main 2002. Ihde, J., J. Adam, W. Gurtner, B. G. Harrson, M. Sacher, W. Schlueter, G. Woeppelmann (2002): The Height Solution of the European Vertical Reference Network (EUVN). In: Ihde, J. A. Sacher (2002): European Vertical Reference Network (EUVN). Final Documentation. Mitteilungen des Bundesamtes fuer Kartographie und Geodaesie. International Association of Geodesy, Section 1 - Positioning, Commission X - Global and Regional Geodetic Networks, Sub-Commission for Europe (EUREF). Publication No. 11, Vol. I. Frankfurt am Main 2002. Ilk, K.H., Mayer-Gürr, T., Feuchtinger, M. (2003): Gravity Field Recovery by Analysis of Short Arcs of CHAMP, Proceedings of the 2nd Science Workshop of CHAMP, accepted for publication. - 89 - JPL (2002a): Scientists Say 'Grace' as Water-Sensing Satellite Lift Off. JPL News (17.3.2002.). JPL (2002b): Satellites Reveal Mystery of Large Change in Earth's Gravity Field (5.8.2002.). Lemoine, F. G., Kenyon, S. C., Factor, J. K., Trimmer, R.G., Pavlis, N. K., Chinn, D. S., Cox, C. M., Klosko, S. M., Luthcke, S. B., Torrence, M. H., Wang, Y. M., Williamson, R. G., Pavlis, E. C., Rapp, R. H., Olson, T. R. (1998): The Development of the Joint NASA GSFC and the National Imagery and Mapping Agency (NIMA) Geopotential Model EGM96. Greenbelt, Maryland 20771. Lühr, H., L. Grunwaldt i Gh. Förste (2002): CHAMP Reference Systems, Transformations and Standards. GFZ Potsdam 2002. Mayer-Gürr, T., Ilk, K.H., Eicker, A., Feuchtinger, M. (2004): ITG-CHAMP01: A CHAMP Gravity Field Model from Short Kinematical Arcs of a One-Year Observation Period, submitted to Journal of Geodesy. Neumayer, K. H., S. Y. Zhu, C. Reigber, R. König i H. Meixner (2000): CHAMP Orbit Recovery Algorithmic Approaches and Preliminary Results. http://op.gfz-potsdam.de/champ/ 2000. Reigber, C., H. Lühr i P. Schwintzer (2001): Announcement of Opportunity for CHAMP. GeoForschungZentrum Potsdam, Potsdam 2001. Reigber, Ch., Balmino, G., Schwintzer, P., Biancale, R., Bode, A., Lemoine, J.-M., Koenig, R., Loyer, S., Neumayer, H., Marty, J.-C., Barthelmes, F., Perosanz, F., Zhu i S. Y. (2002): A high quality global gravity field model from CHAMP GPS tracking data and Accelerometry (EIGEN-1S). Geophysical Research Letters, 29(14), 10.1029/2002GL015064, 2002. Reigber, C., H. Lühr i P. Schwintzer (Eds.)(2003a): First CHAMP Mission Results for Gravity, Magnetic and Atmospheric Studies. Springer-Verlag. Berlin, Heidelberg, New York 2003. Reigber, Ch., Schwintzer, P., Neumayer, K.-H., Barthelmes, F., König, R., Förste, Ch., Balmino, G., Biancale, R., Lemoine, J.-M., Loyer, S., Bruinsma, S., Perosanz, F., Fayard, T. (2003b): The CHAMP-only Earth Gravity Field Model EIGEN-2. Advances in Space Research 31(8), 18831888 (doi: 10.1016/S0273--1177(03)00162-5). Tapley, B., Ch. Reigber (2002): GRACE Newsletter, No, GFZ, CSR, DLR, NASA. UTEX (2003): GRACE Gravity Model 01 - Released July 21, 2003. URL: http://www.csr.utexas.edu/ grace/gravity/. - 90 - TOPOGRAPHIC DATA PRODUCTION AS BASIS FOR NSDI – CROATIAN EXAMPLE* Stipica Pavičić, Mladen Rapaić, Slavko Lemajić ABSTRACT The establishment of the Croatian National Spatial Database Infrastructure have started at the beginning of the 1990's. At the front of the activities was the State Geodetic Administration that gathers surveying and geodetic experts from geodetic companies, science and educational organizations. They built the basic documentation that designates vision and goals, while through studies and pilot projects they developed procedures and exact steps for realization of the goals. SGA by definition and it's internal structure does not have capacities for production of geodetic products, so all production phases are commended to the private geodetic companies in public and open tenders. One of the basic tasks in creation of NSDI is establishment of the Topographic Database, detailed and accurate spatial and seamless database of Croatia that has to serve for wide spectrum of users, from state and local administration, public institutions and state companies to the private companies. The main source for Topographic Database are topographic data collected in systematic and coordinated process by private geodetic companies. By establishment of the Croatian Geodetic Institute the process of Quality controlling the topographic data ensures the homogeneity and alignment of the data to the Product Specifications that serves as a standard in production processes. In front of the geodetic community in Croatia are some important and inevitable steps that will allow integration into the European geospatial system. First of all, the change of geodetic datum and cartographic projection which have to be accommodated regarding new technologies and users' needs and secondly, adoption of the ISO standards, the process that already started in State Office for Standardization and Metrology. KEYWORDS NSDI, geoinformation, topographic database, quality control, ISO 1. INTRODUCTION It is considered nowadays that one of the prerequisites for a country development is the establishment of the National Spatial Database Infrastructure (NSDI). According to Federal Geographic Data Consortium, NSDI implicates: technology, polices, standards and human recourses necessary to acquire, process, store, distribute and improve utilization of geographic data. Republic of Croatia started building its infrastructure soon after proclaiming independency, with the State Geodetic Administration (SGA) in the forefront of activities, but structured and organized without own production and development facilities. By the law and by the status, the SGA has that authority and responsibility and also acts as the National Mapping Organization. In production of topographic data, the specific "Croatian model" (Rožić, 2003) can be recognized, the model that consists of triangle formed by SGA, the Croatian Geodetic Institute and private geodetic companies who actually perform production. The aspect of this paper is concentrated in description of the production process and quality control of topographic data that are used for the Topographic Database uploading. 2. PREPARATORY ACTIVITIES In the middle of the 1990's, the State Geodetic Administration established some of the fundamentals for successful building of infrastructure needed for creation of geodetic products: legal frame, reorganization of geodetic administration and delivery of Program of State Survey and Real Estate Cadastre for the period 2001-2005 that was adopted by the Croatian Parliament and is financed mainly through the State and local administrations' budgets. Major guidelines have been created in cooperation with the experts from the major private companies and from the Faculty of Geodesy (Bačić, 2003). The project STOKIS (Official Topographic and Cartographic Information System of the Republic of Croatia) from 1992 was the basic, general document for creation of digital topographic data. The Predstavljeno na "FIG Working Week 2004" održanom u Ateni, Grčka, 22.-27.5.2004. godine. Dostupno na CD-ROM mediju (Conference proceedings, ISBN 87-90907-30-2, International Federation of Surveyors, 2004) i Internet stranici skupa www.fig.net/pub/athens/programme.htm. * - 91 - following project CROTIS (Croatian Topographic Information System) gave more specific, implementable instructions for production and processing. The fundamental geodetic legislative document, Law on State Survey and Real Estate Cadastre, delivered by the Croatian parliament in 1999 became fundament for the set of law's and bylaw's regulations, such as Ordinance on Topographic Survey Methods and State Map Production, Guidelines for Orthophoto Production, Mapping Catalogue, Cartographic Key, Guidelines for Aerial Photography, Cartographic Generalization with Standardisation for State Maps and others. The first projects were started with the basic scope to overcome technology challenges and to proof the ideas written in previously made documentation. The first products have been very often analogue, but the production processes were more and more managed with the modern, digital equipment. One of the first realized projects that had and still has great influence in further development was cyclic aerial photographing of the whole country (56000 sq km) in scale 1:20000 (Figure 1). Scanning those films with photogrammetric scanner, State Geodetic Administration built the basic source for products such as Digital Orthophoto, Digital Terrain Model and Topographic Data. The crucial support and push in the same time, SGA received from the Croatian parliament in the form of Program of State Survey and Real Estate Cadastre. Some of the tasks that Croatian geodesist have to achieve in the field of topography, are (Official Gazette, 2001): - production of all 603 map sheets of Topographic map 1:25000 (TK25) - maintaining the cyclic aerial photographing of the country in five years time-frame (20% per year) - finishing the project of Croatian Base Map 1:5000 (HOK) that started more than 30 years ago - conversion of all map sheets (approx. 10000) of HOK into digital format - creation of 5000 (50%) map sheets of Digital Orthophoto 1:5000 (DOF) - foundation of digital Registry of Administrative and Spatial Units and - establishment of multipurpose spatial information system for supporting the state and the local administration and public institutions in land management. Fig. 1 Overview map of realisation of cyclic aerial photographing project (State Geodetic Administration, 2003c) Finally, by establishing the Croatian Geodetic Institute (CGI), new institution completely independent in commercial and technological aspects, the State Geodetic Administration acquired the partner (and the tool) for developing and conducting quality control processes of the geodetic products as well as scientific and professional support. The CGI enabled the processing circle of production of - 92 - geodetic products to be fully closed. The CGI defines the "Croatian model" (Rožić, 2003), the framework for clear and undoubtfull duties and responsibilities in the production of national topographic, cartographic and other geodetic products which, besides SGA and CGI, consists of private geodetic companies to whom the whole production is commended. The first tasks of the Institute have been design and execution of the Quality System for newly created Topographic maps 1:25000. In continuation, the work expands on design and execution of quality controls for other geodetic products such as Topographic Data, Orthophoto, Aerial Photographs, etc. 3. PRODUCTION OF TOPOGRAPHIC DATA Previous activities, for the first time after the independence, enabled the geodetic community in Croatia to be in the position to launch the national project that will methodically cover whole country territory in homogenous, standardised way. After establishing the basic prerequisites, general plan was made that promotes topographic data production. Figure 2 shows basic responsibilities and steps and Figure 4 shows details of work that is done during data collection phase within geodetic companies. Fig. 2 Production of topographic data The objective of the program of topographic data production is the seamless Topographic Database (TdB) with positional accuracy of +/-1m on well defined details and +/-3m on other details (State Geodetic Administration, 2001b). By its content and accuracy, the database will be more than appropriate for production of Topographic map 1:25000. Although the data could be used for map production of larger scales (e.g. 1:10000), it is not considered because of the SGA's policy of creation and maintaining the serials of maps in scales 1:5000, 1:25000, 1:50000, 1:100000 and 1:200000. The data should fulfill the wide needs of a different users, from infrastructure object designers and urban planners to the professionals in a local community administration. Data should enable presentation of topographic objects in three dimensions, should be structured logically for the simplicity of acquisition, and the aerial images produced in the on-going project of cyclic aerial photographing have to be used as the main source. The complete production process (except aerial photographing) was put in the hands of several largest private geodetic companies and for assuring the homogeneity of quality and for enabling the automated procedures in certain production steps, it was inevitable to prepare very detailed standards and directions for all production phases. The standardisation of the production process was accomplished in the frame of the CroatianNorwegian Geoinformation project (CRONO-GIP) which goal was "development and implementation of a database within SGA for storage and use of data resulting from the on-going production of new topographic maps in the scale 1:25000" (Rožić et al, 2003). The project was conducted by SGA and CGI and realised in cooperation with Norwegian consulting company Program Management & Mapping along with Croatian geodetic professionals gathered around the Geofoto company. The existing production process was separated into fundamental phases and the result of each phase can be treated as standalone geodetic product: (1) Aerial Photography and Ground Control, (2) Scanned Photo, (3) Aerial Triangulation, (4) Digital Terrain Model, (5) Orthophoto, (6) Topographic Data and (7) Topographic Map 1:25000. In the same time, each of the Products serves as the predecessor for the following production phase (Figure 3) so that each company can be in state to undertake and proceed the job from any other company. Two "main" products are needed for creation of Topographic Database: Topographic Data (TD) and Digital Terrain Model (DTM) and for their production, the Aerial Triangulation is the predecessor. It is planned that each production step in form of the Product will have to be quality controlled and approved before further usage. Although "main", only those Products are not foreseen to be on the market. Instead, the "export" from Topographic Database will be offered. The Product Topographic map 1:25000 is at the end of the - 93 - process line and it represents "derived" product from TdB which may, in the future, become optional as soon as all 600 map sheets are done in the first edition. Fig. 3 Products and products' predecessors Standardisation of the Products is coming out of the Product Specifications that exist in the form of documentation and appropriate analogue and digital appendices. Specifications are designated with the exact version number and, generally, contain following information and instructions: - description and purpose of the Product - common set of terms (Terminology) - data sources, including obligatory predecessors - geographic coverage - coordinate reference systems (horizontal and height) - description of delivery which at least has to have (1) delivery list, (2) Product itself and (3) Technical Report - required content of Technical Report - Products in digital format has to be defined for file format and file arrangement and naming - technical characteristics of the Product - technical characteristic of the equipment used in production process - technical description of the production process - parameters for evaluation of Product's quality - all other relevant information and instructions needed for production (for example, in Technical Specification for Topographic map 1:25000, the appendices (1) Generalisation, (2) Cartographic Key and (3) Map Nomenclature and Names are added). The greatest efforts have been embedded in creation of the specifications for Topographic Data and Topographic Map because the subjective factor has greatest influence during photogrammetric mapping, field data collection, generalisation and cartographic design processes. Specifications are constituent part of the Contract between the State Geodetic Administration and the Producer (private geodetic company). The structure of topographic data is defined by the project Croatian Topographic Information System (CROTIS). Taking into consideration that almost all companies use CAD tools for the photogrammetric data collection, the Mapping Catalogue was created that uniquely defines each feature class by the unique combination of graphic attributes Level, Color, Line Style and Weight, as shown in Table 1 (State Geodetic Administration, 2001a). The Catalogue also defines type of the geometry for feature representation, symbol name for point features and name of the table in the Access database that contains related metadata and attributes. The Mapping Catalogue is constitutional part of the Topographic Data (TD) specification. For undoubtful, unique and homogeneous way of transforming topographic objects in stereomodel to the primitive geometric elements in CAD and for unique attributisation, TD specification contains very detailed instructions called Data Capture Object Selection Criteria that explains topographic objects' definitions, presentation manners and priorities with examples. The result of photogrammetric measurement is completed with data from other sources as well as information (mostly attributes) collected on the field. In the next step, those "raw" data are separated into several files for further compilation. Geometry is connected with the appropriate rows in the appropriate tables. Buildings and land cover are layers that must be topologically correct before uploading into the Topographic Database. To accomplish that requirement, two sets of data must be created: (1) building data compiled from building lines and classification codes related to buildings and - 94 - (2) land cover data compiled from land cover lines and classification codes related to land cover. Companies must clean linear networks in those datasets and establish topology relationship of classification codes to polygon areas. Table 1. Excerpt form Mapping Catalogue that defines unique definition of certain features in Feature group Electric Power System 3100 ELECTRIC POWER SYSTEM DATABASE TABLE UTILITY LINES U_META UTILITY LINES SINGLE ELEMENTS U_META LV CO ST WT 3101 ELECTRIC POWER SUPPLY LINES Line AERIAL LINE 11 0 0 0 UNDERWATER LINE 11 16 2 0 LV CO ST WT CELL Point 3102 SINGLE POWER SUPPLY LINE ELEMENTS METAL POLE 17 0 0 0 3102B CONCRETE POLE 17 0 0 0 3102C The Digital Elevation Model (DEM) must be interpolated and delivered in the form of regular grid. The input data are height points, formlines and natural break lines merged with break lines from the land cover data set (road edges, river banks, etc.) (State Geodetic Administration, 2003b). Final data must be delivered, according to the specifications for Topographic Data and Digital Terrain Model in five MicroStation design files, one Access database and one text file (Figure 4). Fig. 4 Production of topographic data – acquisition, processing and delivery 4. QUALITY CONTROL SYSTEM After Topographic Data and Digital Terrain Model delivery (Figure 4) the process of Quality Control in Croatian Geodetic Institute starts (Figure 5). - 95 - Fig. 5 Controlling and database uploading procedure According to definitions of ISO quality elements, subelements, descriptors, evaluation methods and selected tolerances (ISO, 2001) the Quality Plan is developed. Execution of the Quality Plan on Topographic Data and DTM results with the Quality Evaluation Reports. Short simplified overview of Topographic Data quality control elements and subelements is presented in Table 2. Table 2. Quality elements and subelements used for Topographic Data quality control (State Geodetic Administration, 2003a) ISO Quality Element Quality Subelement Overview Configuration Spatial Characteristics History HW and SW description Model Configuration Completeness Commission Omission Logical Consistency Domain Consistency Check … - That all items are delivered - Readability of digital media Approval of predecessors Producer’s information about hardware/software, calibrations, certificates, licenses, etc. Check interior orientation number of fiducial marks used For analytical plotters, check number of control points/passpoints used for model orientation and their distribution in the model Model orientation error Model orientation gross errors > 3* SD Excessive objects Buildings Utility lines Transportation Hydrography Vegetation and land use Toponyms Feature classes, attributes and values - 96 - ISO Quality Element Quality Subelement Format Consistency Geometric fidelity Thematic Accuracy Positional Accuracy Topological Consistency Classification Correctness Absolute Accuracy Check … - That correct file-naming conventions are used - That MicroStation v7 format is used and with parameters according to product specification - That MS Access v2000 is used - That data contains only points, linestrings and text objects - That dataset has correct topology - Dataset Well defined details Not well defined details Gross errors > 3* SD The process of quality control procedures can be divided in four classes depending of the control type used: manual full (MF), automatic full (AF), manual sample (MS) and automatic sample (AS). Automatic sample control is not included in the CGI quality system procedure. In following chapters the applications of full manual, full automatic and sample manual quality control procedures used in control of Topographic Data are described. 4.1. FULL MANUAL QUALITY CONTROL PROCEDURES Full manual controls are used to check all items identified for the Overview quality element. It has to be manually checked that all expected documents and files are delivered, that the CD media is usable and the files are named according to the Specification (subelement Configuration). The subelement History assures that all predecessors (Figure 3) have been approved. For Topographic Data it has to be checked that product Aerial Triangulation is approved and if the data were produced using scanned photos, the Scanned Photo have to be approved first. To execute this step of control process the contractor have to identify the SGA/CGI's project number and the name of predecessor products, as well as the date for submission of these products to CGI for quality control. Last identified subelement of the Overview quality element is HW and SW description. This subelement requires brief and concise description of hardware and software used in the production. The criteria for acceptance is that the instrument calibration Report is according to the Specification and the vendor name, version number, main purpose of the SW/HW and the technical capabilities for the job are provided. Manual control is also used to check some of the items belonging to quality elements Completeness and Logical consistency. It has to be checked that there is no objects (data) outside of the production area and that the landcover polygons are closed to the production area boundary (subelement Commission). Omission of special objects and omission of the settlement names have to be checked with zero tolerance, but the toponyms of significant hydorographic objects are checked with the different specified tolerance. Domain consistency and the Format consistency are the last two subelements belonging to the quality element Logical consistency that have to be checked in full manual manner, both with zero tolerances. Checking domain, controller have to verify that there is no new, undefined attribute values in Access database and checking format, controller have to verify that all dgn files are version 7 and are readable in MicroStation and that Access mdb file is version 2000 and is readable in MS Access. 4.2. FULL AUTOMATIC QUALITY CONTROL PROCEDURES Full Automatic method in quality control procedure is done with the use of FME (Safe Software Inc.) Workbench files developed firsty under the CRONO GIP project and later in the Croatian Geodetic Institute. A number of quality elements are checked in this way all with zero tolerances. Automatic control is performed after manual control of all items belonging to the Overview quality element. FME Workbench files are designed to detect anomalies in deliverd dgn files relating to Product Specification. Following simple procedure, the controller can detect variety of errors. It can be detected if the object is below minimum size (subelement Minimum Size). Minimum size is defined in Product Specification for buildings (20 m2), landuse (500 m2) and utility lines (10 m). Checking Domain Consistency it can be detected if the features are encoded according to the Product Specification. The - 97 - allowed combinations of level, color, style and weight (example in Table 1) are checked in all dgn files. It can also be detected if the classification text codes for future polygon construction (buildings, landuse areas and elevated areas) are legal according to the Mapping Catalog. Geometric representation in dgn files is also restricted by the Product Specification. Subelement Geometric fidelity is checked for presence of undefined geometry. The only allowed geometry elements are: text, point (cell) and the linestring. Except of described subelements, the automatic control procedure is applied to check the topological consistency. No features are allowed to intersect themselves in Utility, Buildings and Landcover dgn files. Buildings and landcover boundaries are not allowed to cross each other, building boundaries also should not cross landuse boundaries but elevated objects boundaries are allowed to cross other boundaries. Each building, landuse and elevated object polygon must have just one classification point. Automatic control reports if the classification points are multiple or missing. After construction of closed polygons all dangling lines are detected for landuse, buildings and elevated areas. If the automatic control procedure does not fail controller can go ahead with the rest of controlling procedure. One small part of that procedure is presented in the Chapter 4.1. and the rest belongs to the sample manual controlling procedure. 4.3. SAMPLE MANUAL QUALITY CONTROL PROCEDURES Manual control is the most demanding part of quality control procedure. Majority of manual control is done with sampling. Some items belonging to the quality element Spatial Characteristics are checked during automatic control procedure with the FME Workbench files (subelement Minimum Size) but the rest are checked manually with sampling. Sample is used for Model Configuration sublement. Items belonging to that quality subelement have to confirm that the minimum four fiducal marks have been used, that the minimum six points are in Gruber positions and that at least four points are used for absolute orientation of the photogrammetric model. The last item, dealing with Model Configuration that has to be checked is Model Orientation Error. Maximum allowed standard deviation (SD) for model orientation error is set to 0.3 m. Gross errors, which are defined as 3 SD are not allowed. Table 2. is simplified version of real quality control plan that has to be applied. For example, tolerances for checking omission of buildings may not be universally set to some value because some buildings can be treated more important then others. That is the reason why the item Buildings is further divided into few sub-items with different tolerances: residential, not residential, point objects and other objects. Besides omission of buildings, with sampling procedure, the omission of utility lines, transportation, hydrography, the rest of landuse and the rest of toponyms are checked. Most items belonging to the quality element Logical Consistency are checked without sampling. Sampling procedure is applied to check correct spelling of toponyms (subelement Domain consistency) and the proper snapping of road centerline network (subelement Topological consistency). Thematic accuracy quality element is fully checked manually with sampling. This quality element is in the Table 2 roughly presented using the only one quality subelement, Classification Correctness. The real situation is that the dataset is checked with different tolerances dividing the whole dataset into several items belonging to the Buildings, Utility lines and point features, Landuse, Transportation and the Hydrography. Depending of the object significance different tolerances may be used. The main tool in controlling is Digital Photogrammetric Workstation using the original photogrammetric material. The rest of items that has to be checked belongs to the quality element Positional accuracy and the quality subelement Absolute accuracy. For well defined details the tolerance is defined using standard deviation of 1m and for not well defined details the tolerance is 2m. Determination of number of objects in a sample is based on 95% confidence level. To help controller in determination of number of objects in a sample, two statistical tables are made (Table 3). Left table is used for sample based control of errors and missing objects and the right table is used for sample based control of standard deviation. Values presented in table 3. are in conformance with ISO 2859 and ISO 3951. Table 3. Statistical tables for sample size determination based on 95% confidence interval For sample based control of errors and missing objects For sample based control of standard deviation Number of objects Number of objects From To Po (%) = Sample size 1.0 2.0 3.0 5.0 From To Sample size Fdistribution 1 8 all 1 1 1 1 1 26 all 1 9 50 8 1 1 1 1 26 50 5 1.54 51 90 13 1 2 2 3 51 90 7 1.45 - 98 - For sample based control of errors and missing objects For sample based control of standard deviation Number of objects Number of objects From To Po (%) = Sample size 1.0 2.0 3.0 5.0 From Sample size To Fdistribution 91 150 20 2 2 3 4 91 150 10 1.37 151 280 32 2 3 3 4 151 280 15 1.30 281 400 50 3 3 4 6 281 400 20 1.26 401 500 60 3 4 5 7 401 500 25 1.23 Po – tolerance from the Product Specification 4.4. REPORTING QUALITY CONTROL RESULTS In the addition are presented excerpts from typical CGI tables planed for performing and reporting quality control. Those tables as a templates are developed with the use of Microsoft Excel. They are intended to guide the controller in controlling and reporting the quality of dataset. Abbreviations used in following tables are: MF – manual full, MS - manual sample, AF – automatic full, AS – automatic sample, E – Exclusive, Q – Quantitative, SD – standard deviation. Table 4 Excerpt from CGI control items ID ISO Element ISO Subelement Sc2 Spatial characteristics Model configuration Sc3 Spatial characteristics Model configuration Item Distr. of points Model orientation error Eval Type Ctrl type Tol%/ SD Details about control item E MS n/a - minimum 6 in Gruber positions, minimum 4 used for abs. orient. E MS 0.3 meter SD … Table 5 Excerpt from CGI quality control results No Of Obj Obj In Samp Failed object s Fail % Tol% / SD 95% tol Result MS n/a n/a n/a n/a MS n/a 0.3 n/a n/a ID Control Item Eval Typ Ctrl type Sc2 Distribution of points E Sc3 Model orientation error E … Table 6 Example of control details: Number of fiducial marks CONTROL DETAILS Quality control ID ISO Subelement Control Item Control type Result Sc1 Model configuration Number of fiducial marks Manual-Sample n/a Remarks to control result: Additional documentation / screenshots / listings / co-ordinates / … Table 6 contains details of one particular control item. Typically there will be one similar table for each failed control item in the quality control. Reporting of Data Quality Evaluation can be done in different stiles (Lemajić, 2003) and for the future reports CGI is planning to use presented tables (table 4, table 5 and table 6) with some additional informations (dates of delivery and quality control, controller names, ...). In the case of positive quality control result all of dgn files are converted in common coordinate system and at the same time translated in FME format files (ffs). Features belonging to the same CROTIS class and geometry type (area, line or point) form one ffs file. Each topographic feature gets in this stage a "stamp" in form of attributes that denote the contract number (CONTRACT_ID) and quality control identificator (QCID) and gives credit to the future users of Topographic Database that the - 99 - received data is quality controlled. At the end of procedure all of the ffs files are uploaded into the SGA's Topographic Database. Working with real data and inspecting possibility of reaching certain level of quality will help CGI experts to develop and implement more reliable quality system. Besides development of quality system, performing quality control can emphasize weakness of the product specifications and help to make it superior. Errors common to all producers points that something might be incorrectly described or be impossible to achieve. In this early stage of developing the whole production process, it is extremely important to act fast and coordinated between SGA, CGI and production companies in correcting and upgrading product and quality documentations. The particular cases appeared at the first deliveries e.g. the Specification did not foreseen that buildings can form closed polygon, which caused error in automatic control processes. Such examples were solved in direct consultation with SGA and producers and were noticed for change in future versions of Specification. 5. CONCLUSION Republic of Croatia started many processes with the goal to create national spatial data infrastructure. From the technical, technological, organisational, financial and implementable side those processes are carried by experts from geodetic companies, science and educational organisations and state bodies guided by the State Geodetic Administration. Production of spatial data have started, first experiences enabled geodesists to improve implemented documents and technology procedures. Very important part in the cycle of improvement lies on the Croatian Geodetic Institute that controls most of the geodetic Products and is in position to objectively evaluate the Products and its Specification in the same time. It has to be pointed out that the Quality Control System acording to ISO norms is in process of development and implementation and stil not routine. In spite of that, all of the Products are national official standardized products with State warranty. Geodetic community in Croatia still have the obligation to perform several important and inevitable steps that will allow integration into the European spatial system. First of all, it is change of geodetic datum and cartographic projection which have to be accommodated to new technologies and users' needs and adoption of the ISO standards, the process that already started in State Office for Standardization and Metrology. REFERENCES Bačić, Ž., 2003, Outsourcing whole production out of NMO: Croatia as an example, Cambridge Conference, http://www.cambridgeconference2003.com Federal Geographic Data Committee, http://www.fgdc.gov/nsdi/nsdi.html ISO, 2002, ISO 2859 Sampling procedures for inspection by attributes ISO, 2001, ISO 19113 Geographic information - Quality Principles, Draft International Standard, ISO TC/211 ISO, 1989, Sampling procedures and charts for inspection by variables for percent nonconforming Lemajić, S., Rožić, N., Rapaić, M., 2003, Improvement of Quality Control System in Croatia, Proceedings of the ISPRS WG VI/3 Workshop 2003, 168-172, Zagreb, State Geodetic Administration and Croatian Geodetic Society Official Gazette, 2001, Program of State Survey and Real Estate Cadastre for the period 2001-2005, no 64, Zagreb Rožić, N., 2003, Strategy and System of Quality Control of the Official Geographic Data produced by Private Companies in Croatia, Cambridge Conference, http://www.cambridgeconference 2003.com Rožić, N., Lemajić, S., Rapaić, M., 2003, Croatian-Norwegian geoinformation project, Proceedings of the ISPRS WG VI/3 Workshop 2003, 224-227, Zagreb, State Geodetic Administration and Croatian Geodetic Society State Geodetic Administration, 2001a, Croatian Topographical Information System, ver. 1.1., Zagreb, SGA State Geodetic Administration, 2001b, Ordinance on Topographic Survey Methods and State Map Production, Official Gazette, no 55, Zagreb State Geodetic Administration, 2003a, Product Specification Topographic Data 1.0, Zagreb, SGA State Geodetic Administration, 2003b, Product Specification Digital Terrain Model 1.0, Zagreb, SGA State Geodetic Administration, 2003c, Catalogue of Products, Zagreb, SGA - 100 - VISINSKA KONTROLA GEODETSKIH I KARTOGRAFSKIH PROIZVODA U PROCESU TOPOGRAFSKE I KATASTARSKE IZMJERE* Ilija Grgić, Bojan Barišić, Slavko Lemajić SAŽETAK Utemeljenjem Hrvatskog geodetskog instituta (HGI) kao javne ustanove za potrebe obavljanja stručnih poslova sukladno Zakonu o državnoj izmjeri i katastru nekretnina (NN 128/99) stvorene su pretpostavke za kontrolu kvalitete nacionalnih geodetskih i kartografskih proizvoda te za nadzor izvedbe geodetskih radova. Raznim projektnim zadaćama definirana su određivanja i izračuni orijentacijskih točaka za potrebe aerotriangulacije, u pravilu sa svim elementima kojih se proizvođač u procesu izrade konačnog proizvoda mora pridržavati. U procesu izrade geodetskih i kartografskih proizvoda su do sada proizvođači u pravilu računali normalne ortometrijske visine iz modela geoida ili koristeći trigonometrijskim nivelmanom određene visine trigonometrijskih točaka. U ovom radu se želi pokazati na temelju obavljenih kontrola kvalitete da li takav pristup, bez povezivanja određenog broja orijentacijskih točaka na repere državne visinske mreže, može zadovoljiti unaprijed postavljene zahtjeve točnosti. KLJUČNE RIJEČI visinska kontrola, ISO, kontrola kvalitete, model geoida ABSTRACT Important event for quality control of national geodetic and cartographic products in Croatia was establishing of Croatian Geodetic Institute as public institute. Main role of the Institute is to perform high professional tasks according to the Law of state survey and real estate cadastre. Positioning of aerotriangulation’s ground control points with all quality elements which must be followed by the producer are defined within different project tasks. Usually in production of geodetic and cartographic products normal ortometric heights are calculated from geoid model or by using heights of trigonometrical points determined by trigonometrical levelling. This article describes comparison of heights determined by using official geoid model and by geometric levelling to the nearest national vertical reference frame benchmarks. Final result of this comparison will show which projects can use geoid model for heights determination. KEYWORDS height control, ISO, quality control, geoid model 1. UVOD Hrvatski geodetski institut (HGI) utemeljen je kao javna ustanova za potrebe obavljanja stručnih poslova sukladno Zakonu o državnoj izmjeri i katastru nekretnina (NN 128/99), a njegovim utemeljenjem su stvorene pretpostavke za kontrolu kvalitete nacionalnih geodetskih i kartografskih proizvoda te za nadzor izvedbe geodetskih radova. Poslovi kontrole kvalitete obavljaju se za potrebe Državne geodetske uprave (DGU) sukladno razvijenom sustavu kontrole kvalitete u HGI-u zasnovanom na ISO normama. Uvažavajući činjenicu da je HGI u potpunosti osposobljen za obavljanje poslova kontrole kvalitete geodetskih proizvoda koji su rezultat topografske i katastarske izmjere, HGI za potrebe DGU-a pruža Tehničke usluge kontrole kvalitete TK25, digitalnih ortofoto karata u mjerilu 1:5000 i 1:2000 i ostalih geodetskih i kartografskih proizvoda. Temeljna načela po kojima se obavlja kontrola kvalitete primarno su određena odredbama Ugovora, projektnim zadatkom u cjelini, standardima i pravilima struke te posebnim naputcima izdanim od DGU-a. Osim toga, dopunska osnova za obavljanje kvalitete sadržana je u zakonima i važećim propisima te raspoloživim izvornicima. Sadržaj poslova kontrole kvalitete definira elemente kvalitete, izvornike na temelju kojih će se kontrola obaviti te metodu pregleda. Distribucija proizvoda koji su predmet obavljanja kontrole kvalitete vrši se posredstvom DGU-a, a rezultat obavljanja kontrole kvalitete u HGI-u predstavljaju pisana izvješća koja se dostavljaju DGU-u na daljnje postupanje. Projektnom zadaćom definirano je određivanje i izračun orijentacijskih točaka za potrebe aerotriangulacije, u pravilu sa svim elementima kojih se proizvođač u procesu izrade konačnog proizvoda Predstavljeno na Trećem hrvatskom kongresu o katastru s internacionalnim sudjelovanjem, održanom u Zagrebu 7.-9.3.2005. godine. Objavljeno u Zborniku radova Kongresa (Grgić, I., Barišić, B., Lemajić, S.: Visinska kontrola geodetskih i kartografskih proizvoda u procesu topografske i katastarske izmjere. Zbornik radova, Treći hrvatski kongres o katastru s međunarodnim sudjelovanjem, Hrvatsko geodetsko društvo, Zagreb, 2005, 337-343). * - 101 - mora pridržavati. Orijentacijske točke određuju se u državnom koordinatnom sustavu geodetskim metodama mjerenja i instrumentarijem koji preciznošću zadovoljava postavljene zahtjeve točnosti. O obavljenim radovima radovima izrađuje se Elaborat određivanja orijentacijskih točaka, a oblik i sadržaj Elaborata propisuje se projektnom zadaćom. Elaborat u cjelini i pojedinim dijelovima mora sadržavati sva objašnjenja, informacije i podatke koji omogućuju neovisno ponavljanje radova posebno polazne podatke, završne podatke, a po potrebi i međurezultate. U procesu izrade geodetskih i kartografskih proizvoda su do sada proizvođači u pravilu računali normalne ortometrijske visine iz modela geoida ili koristeći trigonometrijskim nivelmanom određene visine trigonometrijskih točaka. U ovom radu se želi pokazati na temelju obavljenih kontrola kvalitete da li se model geoida prema unaprijed postavljenim zahtjevima točnosti može koristiti za sva mjerila kartiranja. 2. METODOLOGIJA Hrvatski geodetski institut već duže vrijeme u kontinuitetu obavlja kontrolu kvalitete geodetskih proizvoda TK25 i Digitalne ortofoto karte mjerila 1:5000 i 1:2000 od različitih proizvoditelja za potrebe Državne geodetske uprave. Sl. 2.1. Postupak kontrole kvalitete Za potrebe sustavne provedbe kontrole kvalitete sadržaja TK25, DOF-a 1:5000 i 1:2000, te provjere apsolutne i relativne točnosti geodetske osnove i topografskog detalja sukladno trenutnoj opremljenosti Instituta mjernim instrumentarijem, obavljaju se planiranja i izvedbe terenskih radova primjenjujući sve geodetske metode izmjere prema zahtjevima sustava kontrole kvalitete. Dokumentacija na temelju koje se provodi postupak kontrole kvalitete u HGI-u je u potpunosti definirana ISO standardima. Izvorni dokumenti koji su poslužili za izradu dokumentacije su sljedeće ISO norme: ISO 19113 Geographic Information-Quality Principles, ISO 19114 Geographic Information - Quality evaluation procedures, ISO 19115 Geographic Information – Metadata, ISO 2859 Sampling procedures for inspection by attributes, ISO 3951 Sampling procedures and charts for inspection by variables for percent nonconforming. Elaborati određivanja orijentacijskih točaka i Elaborati aerotriangulacije u cjelini i pojedinim dijelovima sadržavaju informacije i podatke koje je potrebno, ali ujedno i nemoguće, kontrolirati ukoliko nisu dostupni polazni podaci koji su osnova za kontrolu točnosti u okviru postavljenih zahtjeva prema Pravilniku o načinu topografske izmjere i o izradbi državnih zemljovida, specifikacijama proizvoda, ili prema zahtjevima razvijenog sustava kontrole kvalitete proizašlog iz međunarodnih projekata CRONOGIP I i CRONOGIP II. Tako se orijentacijske točke određuju s instrumentarijem koji osigurava položajno i visinsko određivanje sa standardnim odstupanjem manjim od 1/4 predviđenog dopuštenog odstupanja za njih. U postupku kontrole kvalitete izabire se, ukoliko to u specifikacijama proizvoda nije drugačije definirano, između potpune ili uzorkovane metode. U potpunoj kontroli svi objekti određenog tipa u skupu podataka moraju biti kontrolirani. Taj tip kontrole najviše je prikladan za automatiziranu kontrolu implementirajući adekvatne softvere. Kako bi reducirali količinu posla, kontrolu je moguće obaviti na uzorku a ta metoda je bazirana na općim internacionalnim standardima kojima se utvrđuju veličine uzoraka a to su: ISO 2859 Sampling procedures for inspection by attributes, ISO 3951 Sampling procedures and charts for inspection by variables for percent nonconforming. Nakon što je proizvod podvrgnut kontroli kvalitete potrebno je odlučiti da li se skup podataka koji je kontroliran prihvaća kao dobar, odbija kao loš, ili ga treba proširiti. Samo izvješće o provedenoj kontroli kvalitete trebalo bi sadržavati sljedeće elemente: skup podataka koji je kontroliran, korišteni elementi kvalitete, dopuštena odstupanja, potpuna ili uzorkovana metoda, korišteni hardver i softver, mjerenja i računanja, usporedbu rezultata i odstupanja, te zaključak o prihvaćanju ili odbijanju proizvoda. Sustavna i dosljedna kontrola kvalitete proizvoda koja se provodi u pojedinim organizacijskim jedinicama Hrvatskog geodetskog instituta pretpostavlja vrlo dobru koordinaciju i uvažavanje međusobnih potreba između HGI-a i DGU-a. 3. REZULTATI Za kontrolu DOF-a i DMR-a na području B1/C1, koji pokrivaju prostor od 52 lista DOF-a oko Plaškog, u apsolutnom smislu obavljena su kontrolna nivelmanska mjerenja orijentacijskih točaka u - 102 - odnosu na najbliže repere na 5 različitih lokacija koje su bile definirane odabranim topografskim detaljem. Kontrolna nivelmanska mjerenja orijentacijskih točaka za područje B1/C1, slika 3.1., obavljena su prema normativima za tehnički nivelman, postranim nivelmanskim vlakovima, korištenjem automatskog elektroničkog nivelira LEICA NA3003. Obrada podataka mjerenja i izjednačenje provedeno je primjenom izjednačenja direktnih mjerenja i to tzv. dvostrukih mjerenja. Mjerenja su obavljena u dva suprotna smjera od istog opažača, s istim instrumentom, uz slične vremenske prilike. Najvjerojatnija vrijednost nepoznanice računana je kao (Feil, 1990): X i = ( L1 + L2 ) / 2 (1) Standardno odstupanje najvjerojatnije vrijednosti iz dvostrukih mjerenja dobiva se primjenom zakona o prirastu pogrešaka na izraz (1): sH = 1 d td , 2 n (2) pri čemu je n broj dvostruko mjerenih veličina. Dopuštene razlike pri dvostrukom mjerenju nivelmanskih strana u tehničkom nivelmanu iznose prema Pravilniku o radovima geometrijskog nivelmana (Klak, Feil i Rožić, 1993): d1 = ±8 s mm. (3) Deklarirana mjerna nesigurnost elektroničkog instrumenta LEICA NA3003 na 1 km dvostrukog nivelmana je ±1.5 mm, odnosno ±0.7 mm s certificiranim kodiranim letvama. Kao medij za pohranu mjernih podataka služio je REC-modul. Prema Elaboratu određivanja orijentacijskih točaka normalne ortometrijske visine orijentacijskih točaka računane su iz podataka undulacija geoida, pri čemu je korišten model geoida za područje Republike Hrvatske HRG2000. Normalne ortometrijske visine orijentacijskih točaka iz kontrolnih mjerenja odnose se na najbliže repere iz državne visinske mreže oslonjene na ishodišni reper u Trstu. Legenda: 1 - orijentacijske tocke 2A - koristeni reperi 0 1 2 3 km 4 5 3 4 35 5 35A 6 8 19740 34 8A 22420 9C 37 48 10 11 15 17 16 14 18 33 22425 19 30 31 32 Sl.3.1. Područje B1/C1 Na temelju tako određenih visina, uz pretpostavku primjerene točnosti određivanja položaja i visina orijentacijskih točaka što je u potpunosti realizirano prema ispisu ocjene točnosti, moguće je donijeti ocjenu uporabivosti primjene modela geoida u postupku računanja normalnih ortometrijskih visina uz postavljene zahtjeve točnosti prema Pravilniku o načinu topografske izmjere i o izradbi državnih zemljovida. Tablica 3.1. Visinske razlike između repera i orijentacijskih točaka 19740 Visinska razlika ∆h1 [m] 15.663 Visinska razlika ∆h2 [m] 15.669 Razlika ∆h1-∆h2 [mm] 6 Dopuštena razlika [mm] 8 1.02 ∆h [m] 15.666 8 100.872 100.884 12 13 2.52 100.878 9C 22425 24.432 24.435 3 9 1.32 24.434 10 48 0.502 0.503 1 4 0.29 0.502 33 22420 22.909 22.918 9 9 1.36 22.913 Broj OT Od repera 5 6 - 103 - Udaljenost [km] Na temelju izračunanih visina orijentacijskih točaka proizašlih iz kontrolnih mjerenja za utvrđenu veličinu uzorka sukladno ISO standardu i visina orijentacijskih točaka preuzetih iz elaborata određivanja orijentacijskih točaka za područje projektne zadaće izračunano je standardno odstupanje prema izrazu: s= ε2 ∑n , (4) pri čemu je: s = standardno odstupanje; ε = odstupanje u pojedinoj točci; n = broj točaka u uzorku. Računano Standardno odstupanje po visini 0.1606 Broj korištenih točaka u uzorku 5 Ukupan broj točaka 26 Računana ISO veličina uzorka 5 Računani faktor za veličinu uzorka 1.54 Tablica 3.2. Razlika visina iz skupa podataka i kontrolnih mjerenja Podaci iz skupa podataka da 3 259.55 iz kontrolnih mjerenja Visina (Z) [m] 259.73 da 6 489.97 490.18 -0.206 0.042 da 2 404.03 404.20 -0.174 0.030 da 1 363.72 363.85 -0.132 0.017 da 5 621.04 621.12 -0.082 0.007 Valid St. odst. [mm] Visina (Z) [m] Razlike DZ [m] -0.179 Kvadrat razlike SQ(DiffZ) 0.032 4. ANALIZA Za iskazivanje procjene da li je standardno odstupanje za odabranu veličinu uzorka, tablica 4.1., signifikantno veće od dopuštenog odstupanja koristi se statistička metoda zasnovana na normalnoj razdiobi koja pretpostavlja da standardno odstupanje slijedi normalnu razdiobu. Tablica 4.1. Statističke vrijednosti za testiranje standardnog odstupanja Broj točaka u skupu podataka Od Do 26 50 51 90 91 150 151 280 281 400 401 500 501 1200 1201 3200 3201 10000 10001 35000 35001 150000 150001 500000 > 500000 Veličina uzorka n 5 7 10 15 20 25 35 50 75 100 150 200 200 Standardno odstupanje iz uzorka: Veličina skupa (uzorka): Dopušteno odstupanje za standardno odstupanje: Standardno odstupanje je preveliko ako je: σ< F (F0.05,n-1,∞) 1.54 1.45 1.37 1.30 1.26 1.23 1.20 1.16 1.13 1.12 1.09 1.08 1.08 s=0.1606 m, n=5, σ=0.180 m, s , što u ovom konkretnom slučaju nije ispunjeno F budući je 0.180>0.1043. Nijedna kontrolirana točka za potrebe kontrole DOF-a nije u rezultatima iskazala prisutnost grube pogreške (trostruko standardno odstupanje). Ocjena točnosti obavljenih kontrolnih nivelmanskih mjerenja, tablica 3.2., upućuje na primjerenu preciznost koja je postignuta pri mjerenjima i može poslužiti za procjenu kvalitete određivanja orijentacijskih točaka u apsolutnom smislu u okviru postavljenih zahtjeva točnosti. Položajni opisi orijentacijskih točaka moraju jednoznačno i precizno definirati topografski detalj, te na taj način omogućiti neovisno ponavljanje radova, odnosno obavljanje kontrolnih mjerenja i na temelju njih donošenja pouzdanih zaključaka o kvaliteti određivanja orijentacijskih točaka, - 104 - što se u konkretnom slučaju na orijentacijskoj točci broj 5 pokazalo kao evidentan nedostatak. U svim dosada izrađenim elaboratima kao zajednička karakteristika pokazalo se nedovoljno dobro definiranje orijentacijske točke pa su i za ove točke koje su bile predmet kontrole moguće pogreške u visini pri identifikaciji do 2 cm, što ne mijenja bitno rezultate i zaključke koji su iz njih proizašli. 5. ZAKLJUČAK Obzirom na «Pravilnik o načinu topografske izmjere i o izradbi državnih zemljovida» po kojem maksimalna standardna odstupanja određivanja položaja orijentacijskih točaka za mjerilo kartiranja 1: 5000 iznose položajno 12 cm, a visinski 18 cm, može se reći da razlike visina na orijentacijskim točkama zadovoljavaju uvjete iz Pravilnika. Na temelju rezultata kontrolnih nivelmanskih mjerenja na orijentacijskim točkama, gdje je ostvarena primjerena točnost određivanja visina orijentacijskih točaka, proizlazi da je primjena modela geoida u postupku računanja normalnih ortometrijskih visina uz postavljene zahtjeve točnosti moguća za mjerilo kartiranja 1:5000 i sitnija, dok bi se za krupnija mjerila kartiranja, na temelju provedene kontrole, trebalo izvršiti povezivanje na repere državne visinske mreže. LITERATURA Feil, L. (1990): Teorija pogrešaka i račun izjednačenja - drugi dio, Geodetski fakultet Sveučilišta u Zagrebu. Geodis (2004): Elaborat određivanja orijentacijskih točaka, Elaborat aerotriangulacije i DMR-a – zadaća: CARDS I – blok B1/C1, Zagreb. Klak, S, Feil, L., Rožić, N. (1993): Pravilnik o radovima geometrijskog nivelmana, Prijedlog, Zagreb. Narodne novine (1999): Pravilnik o načinu topografske izmjere i o izradbi državnih zemljovida, Zagreb. - 105 - - 106 - KONTROLA KVALITETE DOF-A U PROCESU KATASTARSKE IZMJERE* Slavko Lemajić, Višnja Miloš, Ilija Grgić SAŽETAK Hrvatski geodetski institut je započeo sa stručnim aktivnostima 1.12.2001. godine. U početnom razdoblju Institut je obavljao poslove kontrole kvalitete topografskih karata u mjerilu 1:25000 i digitalnih ortofoto karata u mjerilu 1:5000. Tijekom vremena preuzeo je i druge zadaće sukladno Programu državne izmjere i katastra nekretnina za razdoblje 2001.-2005. godine (Hrvatski Sabor, 2001). Krajem 2003. godine potpisan je Ugovor između Državne geodetske uprave i Hrvatskog geodetskog instituta za pružanje tehničkih usluga kontrole kvalitete digitalnih ortofoto planova u mjerilu 1:2000 u svrhu uspostave katastra nekretnina i obnove zemljišnih knjiga koji se financira iz zajma Svjetske banke. Institut je u dosadašnjem periodu obavljao kontrolu kvalitete za ukupno 14 katastarskih općina. Kontrola kvalitete za svaku pojedinu katastrasku općinu obavlja se po fazama. U radu je prikazan proces kontrole kvalitete s opisom pojedinih faza kontrole kvalitete. KLJUČNE RIJEČI kontrola kvalitete, plan leta, zračni snimci, skenirani snimci, aerotriangulacija, digitalni model reljefa, digitalni ortofoto ABSTRACT Croatian Geodetic Institute started with professional activties at 1.12.2001. At the beginning period of time Institute has performed quality controls of Topographic maps in scale 1:25000 and digital orthophotos in scale 1:5000. During the time CGI has undertaken and other tasks according to Program for state survey and cadastre 2001.-2005. (Croatian Parliament, 2001). At the end of 2003 was signed the contract between SGA and CGI for tehnical support of quality control of digital orthophotos in scale 1:2000 for establishment of cadastre and real estate which is financed by World Bank. Instittute was done quality control for 14 cadastral municipality. Quality control is done step by step. In paper is shown process of quality control with description of single phase of quality control. KEYWORDS: quality control, flight plan, aerial photos, scanned photos, aerial triangulation, digital terrain model, digital ortophoto 1. UVOD Hrvatski geodetski institut je započeo s obavljanjem stručnih poslova 1.12.2001. godine. U početnom periodu, Institut je uglavnom obavljao pregled topografskih karata u mjerilu 1:25000 te digitalnih ortofoto karata u mjerilu 1:5000. Tijekom vremena započet je proces kontrole ostalih proizvoda i potproizvoda nastalih kao rezultat proizvodnje unutar privatnih geodetskih tvrtki. Svi poslovi kontrole kvalitete obavljeni su za potrebe DGU (Sektor za topografsku izmjeru i državne zemljovide) u okviru realizacije Programa državne izmjere i katastra nekretnina za razdoblje 2001.-2005. godine (Hrvatski sabor, 2001). U drugoj polovici 2004. godine kao rezultat hrvatsko-norveškog geoinformacijskog projekta (CRONO-GIP) razvijen je sustav kontrole kvalitete zasnovan na ISO normama (PMM, 2003). U prosincu 2003. godine potpisan je s Državnom geodetskom upravom Ugovor za pružanje Tehničkih usluga kontrole kvalitete digitalnih orotofoto karata u mjerilu 1:2000 u okviru katastarskih izmjera u svrhu uspostave katastra nekretnina i obnove zemljišne knjige u okviru Projekta sređivanja zemljišnih knjiga i katastra. 2. SPECIFIKACIJA I REALIZACIJA POSLOVA Predmet obavljanja poslova kontrole kvalitete jesu digitalni ortofoto planovi u mjerilu 1:2000. Osim kontrole kavlitete konačnog proizvoda, obuhvaćene su i kontrole kvalitete važnijih faza iz proizvodnog procesa izrade DOF-a. * Predstavljeno na Trećem hrvatskom kongresu o katastru s internacionalnim sudjelovanjem, održanom u Zagrebu 7.-9.3.2005. godine. Objavljeno u Zborniku radova Kongresa (Lemajić, S., Miloš, V., Grgić, I.: Kontrola kvalitete DOF-a u procesu katastarske izmjere. Zbornik radova, Treći hrvatski kongres o katastru s međunarodnim sudjelovanjem, Hrvatsko geodetsko društvo, Zagreb, 2005, 327-335). - 107 - Osnova i temeljna načela primarno su određena sukladno odredbama Ugovora, Tehničkim specifikacijama o izradi DOF-a, standardima i pravilima struke te posebnim naputcima izdanim od DGU. Dopunska osnova za obavljanje kontrole kvalitete sadržana je u pozitivnim zakonima i važećim propisima u Republici Hrvatskoj te raspoloživim izvornicima: Zakon o državnoj izmjeri i katastru nekretnina (Hrvatski Sabor, 1999), Uredba o snimanju iz zraka (Vlada RH, 2003), Pravilnik o načinu topografske izmjere i o izradbi državnih zemljovida (DGU, 2001, u daljnjem tekstu Pravilnik), Uputa za izradu digitalnih ortofoto karata u mjerilu 1:5000-DOF (PMM, 2003), Pravilnik o načinu čuvanja i korištenja dokumentacije i podataka državne izmjere i katastra nekretnina (DGU, 2001). Sadržajem poslova kontrole kvalitete definirani su elementi kvalitete, izvornici na temelju kojih će se kontrola obaviti te metoda pregleda. Elementi kvalitete za koje se pregled obavlja metodom uzorkovanja, izbor veličine uzorka obavlja se sukladno tablici 1 i dokumenta Guidelines for Sampling (PMM, 2004). Tablica 1. Određivanje veličine uzorka Za kontrole metodom uzorkovanja temeljene na pogreškama nedostajanja objekata Broj objekata Po (%) = Veličina od do uzorka 1 8 Svi objekti 9 50 8 51 90 13 91 150 20 151 280 32 281 400 50 401 500 60 Po – dopušteno odstupanje 1. 0 2. 0 3. 0 5. 0 1 1 1 2 2 3 3 1 1 2 2 3 3 4 1 1 2 3 3 4 5 1 1 3 4 4 6 7 Za kontrole metodom uzorkovanja osnovane na kontrolama standardnog odstupanja Broj objekata FVeličina razdio uzorka ba Od Do 1 26 Svi objekti 1 26 50 5 1.54 51 90 7 1.45 91 150 10 1.37 151 280 15 1.30 281 400 20 1.26 401 500 25 1.23 Poslovi kontrole kvalitete obavljaju su u četiri faze. Prva faza sadrži kontrolu kvalitete projekta aerofotogrametrijskog snimanja i rasporeda orijentacijskih točaka, druga faza sadrži kontrolu izvedenog snimanja, treća faza sadrži kontrolu aerotriangulacije bloka, dok se kontrola kvalitete digitalnog modela reljefa i digitalnih ortofoto planova obavlja u četvrtoj fazi. Svaka naredna faza obavljanja radova zahtijeva zadovoljenje kontrole kvalitete u prethodnoj fazi. Institut je do kraja 2004. godine obavljao kontrole kvalitete proizvoda za 14 katastarskih općina u različitim fazama. Posao kontrole kvalitete DMR-a i DOF-a je obavljan u četiri faze: - kontrola kvalitete projekta aerofotogrametrijskog snimanja i rasporeda orijentacijskih točaka, - kontrola kvalitete fotosignalizacije orijentacijskih točaka, prikaza ostvarenog leta, izrade fotomaterijala te izrade digitalnog zapisa snimaka ili skeniranja, - kontrola kvalitete aerotriangulacije, - kontrola kvalitete digitalnog modela reljefa i digitalnih ortofoto planova u mjerilu 1:2000. 2.1. KONTROLA KVALITETE PROJEKTA AEROFOTOGRAMETRIJSKOG SNIMANJA I RASPOREDA ORIJENTACIJSKIH TOČAKA Elementi kvalitete koji su obuhvaćeni kontrolom kvalitete prikazani su u tablici 2. Plan leta s rasporedom orijentacijskih točaka isporučuje se u analognom i digitalnom obliku. Na planu leta mora biti označeno područje snimanja (područje katastarske općine). Planirane razlike mjerila uslijed visinskih razlika terena ne smiju biti veće od 15 % (DGU, 2001). Tablica 2. Kontrola kvalitete projekta aerofotogrametrijskog snimanja i rasporeda orijentacijskih točaka Kontrola Traženi izvornik ili kontrolna vrijednost Izvornik za obavljanje pregleda Mjesto pregleda Način pregleda Isporuka Plan leta Pravilnik Tehničke specifikacije ured Manualni kompletni Pokrivenost područja snimanja Područje zadatka Tehničke specifikacije ured Manualni kompletni Mjerilo snimanja 1:5000 za izgrađena područja, 1:8000 za ostala područja Tehničke specifikacije ured Manualni kompletni - 108 - Preklop Fokusna duljina kamere Raspored orijentacijskih točaka 30% poprečni 60% uzdužni 153 mm Signalizirane točke geodetske osnove Pravilnik Tehničke specifikacije Pravilnik Tehničke specifikacije Pravilnik ured ured ured Manualni kompletni Manualni kompletni Manualni kompletni Izvješće o obavljenoj kontroli kvalitete projekta snimanja s nalazima dostavlja se na daljnje postupanje u DGU uz ocjenu da li je projekt prihvatljiv ili nije. U slučaju da je kontrolom kvalitete ustanovljeno da plan leta nije prihvatljiv, izvoditelj korigira postojeći plan ili izrađuje novi plan te ga dostavlja na ponovni pregled. 2.2. KONTROLA KVALITETE FOTOSIGNALIZACIJE ORIJENTACIJSKIH TOČAKA, PRIKAZA OSTVARENOG LETA, IZRADE FOTOMATERIJALA TE IZRADE DIGITALNOG ZAPISA SNIMAKA ILI SKENIRANJA Druga faza kontrole kvalitete (tablica 3) obuhvaća kontrolu kvalitete fotosignalizacije orijentacijskih točaka, prikaza ostvarenog leta, izrade fotomaterijala te izrade digitalnog zapisa snimaka (skeniranje). Kontrola kvalitete fotosignalizacije obavlja se terenskom provjerom na odabranom uzorku sukladno tablici 1. Na kontaktnim kopijama obavlja se provjera kvalitete preslikanosti i vidljivosti signaliziranih točaka. U Elaboratu fotosignalizacije treba biti razvidno prikazano koje točke su planirane planom snimanja, koje su zamjenske točke te koje točke su se preslikale na kontaktnim kopijama. Na kontaktim kopijama se provjerava numeracija točaka koja na planu orijentacijskih točaka i skici izvedenog snimanja treba biti jedinstvena. Uzdužni preklop kontrolira se za svaki niz mjerenjem baza na snimcima izabranih modela. Modeli se za svaki niz biraju metodom uzorkovanja (tablica 1). Kontrolom kvalitete utvrđuje se maksimalni i prosječni preklop u svakom nizu. Poprečni preklop se mjeri na odabranim mjestima te se utvrđuje da li postoje stereoskopske praznine. Ostvarene visine leta se za svaki niz očitaju sa snimaka i uspoređuju sa projektiranim visinama leta te su izračunaju odstupanja u postocima. Kontrola položajnog odstupanja izvedenih osi nizova od planiranih određuje se nanošenjem središta snimaka na kopiju topografske karte na kojoj je izrađen plan leta. Tablica 3. Kontrola kvalitete fotosignalizacije orijentacijskih točaka, prikaza ostvarenog leta, izrade fotomaterijala te izrade digitalnog zapisa snimaka ili skeniranja Kontrola Isporuka Traženi izvornik ili kontrolna vrijednost Položajni opisi, skica izvedenog snimanja, kalibracija kamere, film, kontaktne kopije Izvornik za obavljanje pregleda Mjesto pregleda Način pregleda Tehničke specifikacije ured Manualni kompletni teren Manualni uzorkovani teren Manualni uzorkovani Izvedena signalizacija Izvedena signalizacija Načina signalizacije Pokrivenost područja snimanja Dimenzija signala 90x30cm Projekt aerofotogrametrijskog snimanja Pravilnik Tehničke specifikacije Područje zadatka Tehničke specifikacije ured Manualni kompletni Tehničke specifikacije ured Manualni kompletni Tehničke specifikacije ured Tehničke specifikacije ured Pravilnik ured Manualni kompletni Tehničke specifikacije ured Manualni kompletni Izvedeno mjerilo snimanja Izvedeni preklopa Fokusna duljina kamere Odstupanja projekcionih centara Kalibracija kamere 1:5000 izgrađena područja, 1:8000 ostala područja 30% poprečni 60% uzdužni 153 mm Planirani položaji projekcionih centara Kalibracija kamere izvršena ne kasnije od dvije godine - 109 - Manualni kompletni Manualni kompletni Vrsta filma Kvaliteta filma Stereoprekrivanje Kvaliteta snimanja Format digitalnog zapisa Čitljivost digitalnog zapisa Kvaliteta skeniranja AGFA COLOR H 100 Film (denzitometrijska mjerenja, oštećenja, kompletnost informacija) Potpuno stereoprekrivanje Prisutnost oblaka, magle, sjena, vegetacije i snijega «tiff», rezolucija 28µm Tehničke specifikacije ured Manualni uzorkovani Pravilnik ured Manualni uzorkovani Pravilnik ured Manualni Uzorkovani Pravilnik ured Manualni Uzorkovani Tehničke specifikacije ured Čitljivost datoteka Tehničke specifikacije ured Histogram Specifikacija proizvoda skenirani snimci ured Manualni Uzorkovani Manualni Uzorkovani Manualni Uzorkovani Kontrolom kvalitete fotomaterijala obuhvaćeni su film i kontaktne kopije. Pregledom se ispituje kvaliteta filma tj. da li postoje oštećenja filma uzrokovana razvijanjem ili premotavanjem. Također se obavlja pregled ispravnosti negativa koja se određuje denzitometrijskim mjerenjem (DGU, 2001). Na kontaktnim kopijama provjerava se prisutnost oblaka i dubokih sjena te kvaliteta preslikavanja i korektnost označavanja fotosignala. Skenirani snimci trebaju biti isporučeni po nizovima snimanja. Svi digitalni zapisi moraju biti čitljivi. Veličina slikovnog elementa mora biti 28µm ili bolja sukladno Tehničkim specifikacijama. Eventualna oštećenja koja su bila uočena na filmu trebaju biti uklonjena postupkom retuširanja u procesu obrade skeniranih snimaka. Za svaki snimak u digitalnom zapisu koji je predmet kontrole kvalitete obavlja se kontrola kvalitete krivulje histograma. Za skenirane snimke u boji postoje tri krivulje histograma, tj. za svaku boju iz RGB spektra boja (crvena, zelena i plava). Izgled krivulja za svaku boju mora biti sličan (PMM, 2003), tj. svaka krivulja mora biti u približno istom rasponu tonova (10-250). 2.3. KONTROLA KVALITETE AEROTRIANGULACIJE Kontrola ispravnosti i točnosti izjednačenja bloka aerotriangulacije obavlja se sukladno članku 14. i članku 15. Pravilnika i obuhvaća elemente navedene u tablici 4. Pri kontroli kvalitete treba voditi računa kojom metodom su određene vezne točke budući da se metoda automatskog određivanja veznih točaka može primjenjivati isključivo na ravničastim područjima bez vegetacije s jednostavnom teksturom koja se ne ponavlja. Povećanjem rezolucije ne postiže se proporcionalno povećanje točnosti (Geodetski fakultet, 2003). Osim navedenog, potrebno je obratiti pažnju na pravilan raspored i odgovarajuću točnost osnovnih zadanih točaka bloka, ispravnost ulaznog podatka za visinu osnovnih zadanih točaka bloka (promjena visine za visinu stabilizacije), valjanost kalibracije ili kontrole kalibracije stereoinstrumenta, odnosno pri korištenju digitalnih fotogrametrijskih sustava važna je valjanost kalibracije i kontrola kalibracije skenera, kvaliteta unutarnje orijentacije, postavljanje ispravnih parametara u računanju aerotriangulacije, te analiza dobivenih rezultata. Tablica 4. Kontrola kvalitete aerotriangulacije Kontrola Traženi izvornik ili kontrolna vrijednost Izvornik za obavljanje pregleda Mjesto pregleda Način pregleda Isporuka Elaborat AT Pravilnik ured Manualni kompletni Pravilnik ured Manualni kompletni Pravilnik ured Manualni kompletni Tehničke specifikacije ured Manualni kompletni Sadržaj Elaborata Raspored OT Točnost aerotriangulacije Sadržaj Elaborata (Tehničko izvješće, pregledna skica, mjerenje, izjednačenje itd) Pravilan raspored OT Max. Srednja pogreška izjednačenja bloka M=±0.10m - 110 - Kompletnost Unutarnja orijentacija Elementi vanjske orijentacije, Izjednačene koordinate Unutarnja orijentacija i br. korištenih rubnih markica (min. 4) Pravilnik ured Manualni kompletni Pravilnik ured Manualni uzorkovani Proces kontrole kvalitete koju trenutno provodi Institut obavlja se isključivo kontrolom dostavljenih Elaborata aerotriangulacije, slijedeći elemente kvalitete navedene u tablici 4. Kontrolom kvalitete Elaborata aerotriangulacije uglavnom se uočavaju sljedeći nedostaci: nepotpunost isporuke tj. nedostatak ključnih dijelova Elaborata aerotriangulacije, dimenzije signala u neskladu s dimenzijama signala zadanim u Tehničkim specifikacijama, što dovodi do pogrešaka u izmjeri, visine osnovnih zadanih točaka bloka nekorigirane za visinu stabilizacije, pri korištenju digitalnih fotogrametrijskih sustava nepoštivanje pravila o kontroli kalibracije skenera, budući se različitim parametrima skeniranja dobiju različiti podaci koji su polazište za daljnji rad. Pri velikim promjenama parametara skeniranja može doći do nesuglasja zadataka izvedenih s različitim parametrima skeniranja, opažanje točaka koje se nalaze bliže od 10 mm od ruba snimka što nije ispravno zbog pada kvalitete snimke i moguće promjene dimenzije emulzije, ocjena točnosti «a priori» zadanih koordinata ne odgovara ocjeni točnosti dobivenoj u određivanju orijentacijskih točaka, kriteriji za prekid iteracija računanja bloka zadani s nerealnim veličinama. 2.4. Kontrola kvalitete DMR-a i DOF-a Nakon obavljanja kontrole kvalitete aerotriangulacije i prihvaćanja rezultata računanja i kontrole aerotriangulacije pristupa se četvrtoj i posljednjoj fazi kontrole kvalitete (tablica 5). Uz ispunjavanje uvjeta isporuke (izvješće, digitalni zapis DMR-a i DOF-a) pristupa se kontroli kvalitete digitalnog zapisa (format zapisa i čitljivost datoteka). Podaci DMR-a trebaju sadržavati prijelomnice, strukturne linije (linije oblika), pojedinačne markantne točke te raster visinskih točaka na pravilnom razmaku. Kontrola kvalitete podataka DMR-a obavlja se vizualnom provjerom izračunatog modela (sjene) pomoću kojeg je moguće otkrivanje grubih pogrešaka. Također, provjera grubih pogrešaka obavlja se i streoskopskim promatranjem izabranih modela. Tablica 5. Kontrola kvalitete DMR-a i DOF-a Kontrola Isporuke Format digitalnog zapisa DMR-a Čitljivost digitalnog zapisa DMR-a Struktura podataka Točnost DMR-a DOF Traženi izvornik ili kontrolna vrijednost Izvješće, digitalni zapis DMR-a, digitalni zapis DOF-a Izvornik za obavljanje pregleda Mjesto pregleda Način pregleda Pravilnik o ured Manualni kompletni Format zapisa DXF Tehničke specifikacije ured Manualni kompletni Čitljivost datoteke Tehničke specifikacije ured Manualni kompletni Pravilnik Tehničke specifikacije ured Automatski kompletni Tehničke specifikacije teren Manualni uzorkovani Tehničke specifikacije ured Manualni kompletni Prijelomnice, strukturne linije, karakteristične točke, točke grida m=±0.20m za izgrađeno područje m=±0.50m za ostalo područje Format zapisa, rezolucija, čitljivost zapisa, histogram, dimenzije DOF-a, veze listova - 111 - Kartografski sadržaj Točnost DOF-a Format zapisa, vanjski opis (službena podjela detaljnih listova kat. plana 1:2000) m=±0.20m za izgrađeno područje, m=±0.50m za ostalo područje Tehničke specifikacije ured Manualni kompletni Tehničke specifikacije teren Manualni uzorkovani Točnost DMR i njegova kvaliteta direktno je povezana i reflektira se pri izradi DOF-a. Mjerene vrijednosti točaka profila (prave vrijednosti) uspoređuju se s interpoliranim visinama podataka DMR-a te se računaju standardna odstupanja. Sukladno Tehničkim specifikacijama tražena točnost DMR-a mora biti ±0.20m za izgrađeno područje i ±0.50m za ostala područja. Kontrolom kvalitete DOF-a obuhvaćene su provjere formata i čitljivosti digitalnog zapisa, veličina slikovnog elementa (0.20m) te dimenzije lista (7500x5000 slikovnih elemenata). Svi listovi moraju biti tonski izjednačeni bez vidljivih prijelaza pri izradbi mozaika. Krivulja histograma za svaki list DOF-a mora biti ujednačena. Također, na spojevima listova DOF-a ne smije postojati tonska razlika uslijed eventualnog tonskog izjednačenja svakog pojedinog lista. Kartografski sadržaj za svaki list sastoji se od vanjskog opisa i okvira sukladno službenoj podjeli na detaljne listove. Svi elementi moraju biti sadržani u jednom sloju i isporučeni u DWG digitalnom zapisu. 3. ZAKLJUČAK Tijekom 2004. godine Institut je obavljao kontrole kvalitete potproizvoda i proizvoda u procesu katastarskih izmjera sukladno Ugovoru za pružanje tehničkih usluga kontrole kvalitete. Budući da su definirani rezultati rada, navedeni u Tehničkim specifikacijama, Institut je proces kontrole kvalitete razložio na četiri faze. Takav pristup u sustavu kontrole kvalitete pokazao se opravdanim jer je osigurao kvalitetno praćenje procesa proizvodnje DMR-a i DOF-a kao ciljanog proizvoda. Poznavajući traženu vrijednost, tj. zahtjevanu točnost potproizvoda i konačnih proizvoda, ovakvim pristupom osigurani su traženi uvjeti. Također, evidentiranjem i otklanjanjem nedostataka u ranoj fazi proizvodnog procesa postignuta je veća sigurnost da su konačni proizvodi sukladni normativno tehničkoj osnovi. Izradom ili uvođenjem odgovarajućih specifikacija za proizvode DMR i DOF, koji se izrađuju iz zračnih snimaka mjerila 1:5000 i 1:8000 i detaljno definiraju proizvodni proces, proizvod te dopuštena odstupanja zasigurno mogu homogenizirati i ujednačiti dosadašnji različiti pristup pri izradbi digitalnog ortofota u procesu katastarskih izmjera. LITERATURA Hrvatski sabor, 1999: Zakon o državnoj izmjeri i katastru nekretnina, Narodne novine br. 128/99, Zagreb Hrvatski sabor, 2001: Program državne izmjere i katastra nekretnina za razdoblje 2001-2005, Narodne novine br. 64/2001, Zagreb DGU, 2001.: Pravilnik o načinu topografske izmjere i o izradbi državnih zemljovida, Narodne novine 55/01, Zagreb DGU, 2001.: Pravilnik o načinu čuvanja i korištenja dokumentacije i podataka državne izmjere i katastra nekretnina, Narodne novine 55/01, Zagreb Vlada RH, 2003.: Uredba o snimanju iz zraka, Narodne novine 116/03, Zagreb PMM, 2003.: Uputa za izradu digitalnih ortofoto karata u mjerilu 1:5000 (DOF), DGU, Zagreb PMM, 2003.: Specifikacija proizvoda DMR, DGU, Zagreb. PMM, 2003.: Specifikacija proizvoda zračni snimci i orijentacijske točke, DGU, Zagreb PMM, 2003.: Specifikacija proizvoda skenirani snimci, DGU, Zagreb PMM, 2003.: Specifikacija proizvoda aerotriangulacija, DGU, Zagreb PMM, 2004.: Guidelines for Sampling, HGI, Zagreb Geodetski fakultet, 2003.: Studija o aerotriangulaciji, DGU, Zagreb - 112 - METODOLOGIJA ODREĐIVANJA CRTE SREDNJIH VIŠIH VISOKIH VODA* Bojan Barišić, Ivica Vilibić, Ilija Grgić SAŽETAK Crta srednjih viših visokih voda (SVVV) određuje granicu unutar pomorskog dobra između morske obale i ostalog dijela pomorskog dobra. Razradom pravne regulative vezane uz pomorsko dobro javlja se potreba da se crta SVVV kvalitetno i jednostavno odredi. Pošto je crta SVVV usko vezana uz mareografska mjerenja, za shvaćanje njene definicije potrebno se upoznati s rezultatima tih mjerenja. Praktično određivanje crte SVVV svodi se na prijenos visina različitim nivelmanskim metodama pri čemu je neophodno korištenje točaka visinskog sustava. Pošto se trenutno nalazimo u prelaznom razdoblju u kojem je potrebno dosadašnju upotrebu povijesnog referentnog visinskog sustava zamijeniti novim referentnim visinskim sustavom, više pažnje bit će posvećeno tome što nam te promjene donose. KLJUČNE RIJEČI pomorsko dobro, morska obala, mareografska mjerenja, srednje više visoke vode, hrvatski visinski referentni sustav – HVRS71 ABSTRACT Border between seacoast and remain parts of maritime domain is defined by the mean higher high water (MHHW) line. Improvements in related lows are requesting well and easy practical definition of the MHHW line. Tide gauge measurements are unavoidable in explanations of the MHHW line. Different levelling methods are used to link national vertical reference frame benchmarks with aim to practically define MHHW line. This is the time when Croatia is changing old vertical reference system to new one and impact on the MHHW line determination is described. KEYWORDS maritime domain, seacoast, tide gauge measurements, mean higher high water, Croatian vertical reference system – HVRS71 1. UVOD Posljednjih godina sve se više počinje prepoznavati prirodna i gospodarska vrijednost našeg obalnog područja te porast interesa za njegovim iskorištavanjem, kako od strane domaćih tako i inozemnih poduzetnika. Želja da se naš obalni pojas što bolje zaštiti od stihijskog razvoja i devastacije, kojima je bio izložen nekoliko posljednjih desetljeća, urodila je izradom nove te razradom već postojeće zakonske regulative. Njom se, osim zaštite ovog osjetljivog dijela našeg teritorija, omogućava i iskorištavanje njegove već davno prepoznate gospodarske vrijednosti. Granicu pomorskog dobra s morske strane predstavlja vanjska granica teritorijalnog mora Republike Hrvatske. Ona pak predstavlja morski pojas širok 12 morskih milja, računajući od polazne crte u smjeru gospodarskog pojasa. Granica pomorskog dobra s kopnene strane određena je njenom obalnom komponentom (Roić i Racetin, 2003). Poseban dio našeg obalnog područja je morska obala koja spada u jedan od dijelova kopna koji zajedno s unutarnjim morskim vodama, teritorijalnim morem, njihovim dnom i podzemljem, te u moru i morskom podzemlju živim i neživim prirodnim bogatstvima čine pomorsko dobro. Morska obala proteže se od crte srednjih viših visokih voda mora i obuhvaća pojas kopna koji je ograničen crtom do koje dopiru najveći valovi za vrijeme nevremena, kao i onaj dio kopna koji po svojoj prirodi ili namjeni služi korištenju mora za pomorski promet i morski ribolov, te za druge svrhe koje su u vezi s korištenjem mora, a koji je širok najmanje šest metara od crte koja je vodoravno udaljena od crte srednjih viših visokih voda («Narodne novine», br. 158/03). Za svaku županiju na čijem području postoji pomorsko dobro osniva se županijsko povjerenstvo za granice pomorskog dobra. Povjerenstvo izrađuje prijedlog granice pomorskog dobra temeljem godišnjeg plana upravljanja pomorskim dobrom ili iznimno temeljem zahtjeva. Zahtjev za utvrđivanje granice pomorskog dobra podnosi se Povjerenstvu. Podnositelj zahtjeva za utvrđivanje granice Predstavljeno na Trećem hrvatskom kongresu o katastru s internacionalnim sudjelovanjem, održanom u Zagrebu 7.-9.3.2005. godine. Objavljeno u Zborniku radova Kongresa (Barišić, B., Vilibić, I., Grgić, I.: Metodologija određivanja crte srednjih viših visokih voda. Zbornik radova, Treći hrvatski kongres o katastru s međunarodnim sudjelovanjem, Hrvatsko geodetsko društvo, Zagreb, 2005, 351-358). * - 113 - pomorskog dobra može biti Vlada Republike Hrvatske putem Ministarstva mora, turizma, prometa i razvitka, tijela državne uprave, tijela jedinice lokalne samouprave i fizičke i/ili pravne osobe. Jedan od priloga u tom zahtjevu je i geodetski snimak područja ili ortofoto plan s uklopljenom kopijom katastarskog plana, koji se izrađuje u skladu s propisima o topografskoj izmjeri i obavezno sadrži liniju koja predstavlja crtu SVVV i liniju koja je šest metara udaljena od te crte («Narodne novine», br. 8/04). Prema Zakonu o pomorskom dobru i morskim lukama crtu SVVV utvrđuje Hrvatski hidrografski institut (HHI). Praktično HHI određuje razliku između geodetske nule i razine SVVV za određeno područje ili prosjek za cijelu obalu, dok geodetska tvrtka, koja izrađuje geodetski snimak područja ili ortofoto plan, pomoću te razlike utvrđuje granicu između morske obale i ostatka pomorskog dobra. Spomenuta granica dijelom definira česticu pomorskog dobra na morskoj obali tj. određuje njenu granicu prema moru. Njena važnost prema sadašnjim propisima velika je i u slučajevima kada se pojas morske obale određuje na šest metara od crte SVVV. Bez obzira na buduće promjene zakonske regulative, granica između morske obale i ostalog dijela pomorskog dobra (crta SVVV) ima veliki značaj pri evidenciji i obilježavanju pojasa pomorskog dobra, pogotovo kada se uzme podatak da je duljina naše obale 5835 km. Kad se radi o određivanju visine neke točke potrebno se osloniti na točke službenog visinskog sustava (repere). Uvođenjem novog visinskog referentnog sustava - HVRS71, dolazi do određenih promjena u odnosu geodetske nule i razine SVVV, budući da je stari visinski referentni sustav po svojoj definiciji prilično različit od novog. Pošto su u službenoj upotrebi još uvijek oba visinska sustava treba vidjeti što nam primjena visina repera iz određenog sustava donosi. U područjima gdje je potrebna veća točnost određivanja crte SVVV, a posebno u područjima gdje je mali pad morske obale pa krivo određena visina znači pomak od nekoliko metara u horizontalnom smislu, posebnu pozornost treba posvetiti točnosti visina. Kvaliteta visinskog sustava vezana je uz točnost visine njegove okosnice. Nehomogenosti u točnosti starog sustava izravno dovode do nehomogenosti u točnostima pri određivanju crte SVVV. 2. MAREOGRAFSKA MJERENJA Dugoperiodičke oscilacije razine mora (podrazumijevaju se periodi veći od cca 1 min) najvećim su svojim dijelom uzrokovane djelovanjem plimotvorne sile kao i djelovanjem atmosferskih sila, u prvom redu djelovanjem tlaka zraka i vjetra. Plimotvorna sila je uzrokovana gravitacijskim privlačenjem vodenih masa od strane Sunca i Mjeseca. Njezino djelovanje ima periodički karakter, sa najjače izraženim poludnevnim i dnevnim komponentama. Djelovanjem plimotvorne sile morska razina periodički oscilira, a epizode rasta odnosno pada razine mora definiramo kao morske dobi. Plima se definira kao vrijeme rasta razine mora, dok oseka predstavlja vrijeme opadanja razine mora. Utjecaj plimotvorne sile može mijenjati razinu mora preko deset metara u svjetskim oceanima, a u Jadranskom moru kao poluzatvorenom bazenu od tridesetak centimetara u južnom Jadranu do jedan metar u sjevernom Jadranu. Obzirom na konstelaciju Mjeseca i Sunca plimne oscilacije u Jadranskom moru su mješovitog tipa, što znači da u pojedinim periodima dominiraju poludnevne komponente dvaput izmjenjujući morske dobi u jednom danu (slika 1), dok u pojedinim periodima prevladavajući utjecaj imaju dnevne komponente uzrokujući jednu plimu i oseku dnevno. Uređaji koji registriraju periodične oscilacije morske razine nazivaju se mareografi, dok je izgled tih oscilacija, kao rezultat mareografskih mjerenja, prikazan pomoću mareograma. 1.0 0.9 niže visoke vode više visoke vode razina mora [m] 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 pon. više niske vode uto. niže niske vode sri. dan cet. pet. Slika 1: Izgled mareograma kod poludnevnog tipa morskih mijena - 114 - Razina srednjih viših visokih voda dobije se kao aritmetička sredina, za određeni period (mjeseci, godina), onih visokih voda koje su za poludnevni tip morskih mijena tijekom jednog dana više. Srednja morska razina (SMR) je za geodeziju vrlo važan nivo i često služi za određivanje visinskog datuma, a definira se kao aritmetička sredina satnih vrijednosti visina morske razine u nekom periodu. Važno je naglasiti da je mareografska mjerenja moguće povezati sa službenim visinskim datumom preko repera koji se nalaze u blizini mareografa, te na taj način odrediti odnos između geodetske nule i ostalih razina. Na taj način se može povezati i SMR na pojedinim postajama sa službenim visinskim datumom te interpolirati za bilo koje područje na jadranskoj obali. Nakon toga se, za izračun crte SVVV u odnosu na službeni visinski datum u cjelokupnom obalnom području Jadrana, može koristiti više metoda: (i) izračunati razinu SVVV u odnosu na datum na pojedinim mareografskim postajama te načiniti linearnu interpolaciju, (ii) izračunati razinu SVVV u odnosu na datum u svakoj točki uz obalu pomoću empirijski dobivenih razdioba amplitude i faze pojedinih harmonijskih komponenti (npr. Polli, 1960), ili (iii) izračunati razinu SVVV u odnosu na datum u svakoj točki pomoću vrijednosti amplitude i faze pojedinih harmonijskih komponenti dobivenih numeričkim modelima. 3. REFERENTNI VISINSKI SUSTAVI U RH Budući da se određivanje crte SVVV u slučaju kada znamo njen odnos prema geodetskoj nuli (podatak HHI-a) svodi samo na iskolčenje visine, više ćemo pažnje posvetiti visinskom sustavu, jer se trenutno nalazimo u prelaznom razdoblju u kojem je potrebno dosadašnju upotrebu povijesnog referentnog visinskog sustava zamijeniti novim referentnim visinskim sustavom - HVRS71. Povijesni geodetski visinski sustav, koji se još uvijek nalazi u službenoj upotrebi, ustrojen je za vrijeme postojanja Austro-Ugarske monarhije. Njegov visinski datum vezan je uz vremensku epohu 1875. godine i određen je srednjom razinom mora na mareografu u Trstu iz jednogodišnjih mjerenja. Drugu komponentu geodetskog visinskog sustava čini kao okosnica polje trajno stabiliziranih i do izvedbe mjerenja I. nivelmana visoke točnosti (I. NVT; 1946-1953) očuvanih repera austrijskog preciznog nivelmana (APN; 1874-1909), na koje su, uz zadržavanje njihovih izvornih nadmorskih visina, uklopljena mjerenja I. NVT-a najjednostavnijim računskim postupcima i parcijalnim izjednačenjima (Feil i dr., 2003). Državna geodetska uprava zadužena je da uvede nove službene geodetske datume i ravninske kartografske projekcije u službenu uporabu, najkasnije do 1. siječnja 2010. godine. Novom visinskom referentnom sustavu određuje se naziv – Hrvatski visinski referentni sustav za epohu 1971.5 – skraćeno HVRS71. Ploha geoida koja je određena srednjom razinom mora na mareografima u Dubrovniku, Splitu, Bakru, Rovinju i Kopru u epohi 1971.5 određuje se referentnom plohom za računanje visina u Republici Hrvatskoj. Visinska mreža koju čine trajno stabilizirani reperi II. nivelmana visoke točnosti (II. NVT; 19701973) određuje se osnovom visinskog referentnog sustava Republike Hrvatske («Narodne novine», br. 110/04). Iz samih definicija službenih visinskih sustava u Republici Hrvatskoj vidljivo je da je teško očekivati njihovo podudaranje. Na slici 2. su zorno prikazana njihova međusobna odstupanja, i to na mareografskim postajama od Kopra do Dubrovnika, čijim su mjerenjima određene srednje morske razine koje definiraju novi visinski datum. Slika 2: Srednja razina Jadrana u odnosu na N. N. Trsta (Jovanović, 1978) Pošto u vrijeme izvođenja nivelmanskih radova na definiciji okosnice starog visinskog sustava nisu postojali mareografi na koje se oslanja novi sustav, tek je nakon njihove instalacije i dovoljnog broja godina registracije bilo moguće povezati ih na stari visinski sustav te dobiti razlike između starog datuma - 115 - i srednje morske razine u tim područjima. Uzme li se u obzir da je novi datum definiran srednjom morskom razinom upravo na tim mareografima, može se reći da se ovom kontrolom dobila razlika u datumima na mareografskim postajama između starog i novog visinskog sustava (slika 2). Razlike prikazane na slici 2. izračunate su na način da je visina repera koji se nalazi u blizini svake pojedine mareografske postaje određena na dva načina. Jednom iz njegove visine u odnosu na srednju morsku razinu dobijenu na osnovu dugogodišnjih mareografskih mjerenja obližnjeg mareografa (približna visina repera u novom sustavu), a drugi put povezivanjem repera geometrijskim nivelmanom na službene repere povijesnog referentnog visinskog sustava (visina repera u starom sustavu). Za naglasiti je da se radi o približnim visinama repera u novom sustavu, jer je srednja morska razina određena iz dovoljnog broja godina, ali u drugom vremenskom periodu od perioda koji se koristio za određivanje novog visinskog datuma, no njihove razlike u ovim razmatranjima mogu se zanemariti zbog svog malog iznosa. Praktično značenje prikazanih razlika vidljivo je iz službenih podataka repera za koje su dane visine u oba sustava. Tako će primjerice visina nekog repera u području Splita u novom sustavu biti za oko 31 cm manja u odnosu na njegovu visinu u starom sustavu. Nadalje, u području Zadra razlika sustava iznosi oko 32 cm što se ne slaže sa slikom 2. To je stoga jer razlike vrijede samo u područjima u kojima su prikazane i nije moguće izvršiti interpolaciju te dobiti razlike u nekom drugom području koje se nalazi između navedenih mareografa. Razlog je nehomogenost u točnosti kojom je određena referentna okosnica starog sustava. Razlika između sustava je nastala iz više razloga. Osnovni uzroci su različito definirani datumi te kvaliteta i obrada mjerenja kojima su definirane visinske referentne okosnice. Stari visinski datum definiran je iz jednogodišnjih mjerenja mareografa u Trstu i vezan je uz epohu 1875. godine, dok je novi datum određen na osnovu mjerenja pet mareografa iz punog perioda od 18.6 godina te je vezan uz epohu 1971.5. Dio problema je u različitim epohama u kojima su datumi definirani, jer razdoblje između tih epoha je gotovo stotinu godina, dok je dio u tome što je za definiranje starog datuma korišten samo jednogodišnji period koji je te godine bio oko 12 cm niži od višegodišnjeg prosjeka. Jedan visinski sustav, osim datumom, definiran je i svojom okosnicom koju čini polje stalnih točaka stabiliziranih na terenu, čije su visine određene geometrijskim nivelmanom. Visinska okosnica starog sustava definirana je mjerenjima APN-a, dok je novi sustav definiran mjerenjima II. NVT-a. Bez obzira na sustavnost nivelmanskih mjerenja APN-a, podaci mjerenja nisu jedinstveno izjednačeni, već je mreža izjednačena u nekoliko dijelova što je dovelo do nepravilnog nagomilavanja pogrešaka te utjecalo na točnost nadmorskih visina repera. Terenska mjerenja mreže II. NVT-a obavljena su sustavno u razdoblju od četiri godine, a upotrebljen je unificirani instrumentarij i pribor te su jasno precizirani znanstveni i stručni kriteriji. Svi podaci mjerenja obuhvaćeni su sustavnom računskom obradom i znanstvenom analizom, prema suvremenim zahtjevima nivelmana visoke točnosti. Iz činjenice da je stari datum oslonjen samo na jedan mareograf proizlazi zaključak da se specifičnošću primijenjenih postupaka izjednačenja, te nagomilavanjem raznih sistematskih pogrešaka pri mjerenjima APN-a, njegova apsolutna točnost udaljavanjem od Trsta pogoršava (slika 2), dok je novi visinski datum oslanjanjem na pet mareografa uzduž istočne obale Jadrana jako dobro vezan uz srednju morsku razinu. Još jedna od bitnih karakteristika novog sustava je homogenost njegove točnosti koja omogućava kvalitetno određivanje srednje morske razine na cijeloj našoj obali odnosno crte SVVV nakon primjene podataka HHI-a. Tome u prilog ide i činjenica da odstupanja visinskih razlika između susjednih mareografa određenih mrežom II. NVT-a i mareografskim mjerenjima iznose maksimalno 2.7 cm (Bilajbegović i dr., 1986) što upućuje na to da bi graf na slici 2. realnije izgledao sa srednjom morskom razinom prikazanom kao os apscise. 4. ZAKLJUČAK Bitan element pri evidenciji i obilježavanju pojasa pomorskog dobra čini crta SVVV. Točnost određivanja crte SVVV najviše ovisi o položenosti morske obale. U slučaju obale koja blago pada značajan utjecaj na točnost određivanja crte SVVV ima točnost određivanja visina - ukoliko se crtu želi odrediti s točnošću od 0.5 m na obali pada 5%, visina SVVV mora biti određena bolje od 2.5 cm. Danas različite nivelmanske metode dostižu visoke točnosti pri prijenosu visina, no pitanje je što je s našim službenim visinskim sustavom koji je nastao prije više od stotinu godina i na čije repere se potrebno osloniti pri određivanju visine SVVV. Referentna ploha starog visinskog sustava pokazuje loše podudaranje sa SMR čemu je razlog sam način određivanja datuma i visinske okosnice, čija je nehomogenost u točnosti nastala uslijed specifičnosti obrade te kvalitete samih mjerenja. Novi visinski sustav, koji se do 2010. godine mora uvesti u službenu upotrebu, pokazuje jako dobro podudaranje sa SMR te homogenost i visoku točnost. - 116 - Budući da dobro određen odnos između starog datuma i SMR imamo samo u područjima mareografskih postaja koje su povezane na okosnicu starog sustava, teško je pretpostaviti što se s tim odnosom događa u područjima koja se nalaze između tih postaja. Za razliku od toga, novi visinski sustav s točkama svoje okosnice pruža kvalitetnu osnovu za određivanje crte SVVV na cijelom području naše obale. Radovi na evidentiranju pomorskog dobra još nisu predaleko odmakli pa bi trebalo razmotriti odluku o određivanju okosnice novog visinskog sustava kao osnove za utvrđivanje crte SVVV. Ukoliko se za određivanje razine SVVV odabere najjednostavnija metoda koja se koristi linearnom interpolacijom između susjednih postaja, trebalo bi odlučiti mjerenja kojih mareografa će se koristiti pri određivanju razlike geodetske nule i razine SVVV, te za te mareografe izračunati razine SVVV iz istog perioda kojim je definiran i novi datum, da bi se izbjegao utjecaj trenda promjene morske razine. LITERATURA Bilajbegović, Asim i dr. (1987): II. nivelman visoke točnosti SR: Bosne i Hercegovine, Crne Gore, Hrvatske, Slovenije i SAP Vojvodine, 1970-1973, Sveučilište u Zagrebu, Geodetski fakultet, Zbornik radova, Niz D, Svezak broj 6/1 Feil, Ladislav i dr. (2003): Izrada dokumentacije neophodne za usvajanje službenog visinskog datuma Republike Hrvatske, elaborat, Sveučilište u Zagrebu, Geodetski fakultet Feil, Ladislav; Rožić, Nevio (2000): Prijedlog službenog visinskog datuma Republike Hrvatske, elaborat, Sveučilište u Zagrebu, Geodetski fakultet Jovanović, Božidar (1978): Izučavanje metoda mjerenja dubina mora, unapređenje obrade dubina i definiranja obalne linije sa hidrografskog, geodetskog i pomorskog gledišta, disertacija, Sveučilište u Zagrebu, Geodetski fakultet Narodne novine (2003): Zakon o pomorskom dobru i morskim lukama 158/03 Narodne novine (2004): Uredba o postupku utvrđivanja granice pomorskog dobra 8/04 Narodne novine (2004): Odluka o utvrđivanju službenih geodetskih datuma i ravninskih kartografskih projekcija Republike Hrvatske 110/04 Polli, Silvio (1960): Le propagazione delle maree nell' Adriatico. Atti del IX Convegno dell' Associazione Geofisica Italiana, Roma, 1-11. Roić, Miodrag; Racetin, Ivana (2003): Evidencije pomorskih područja, Geodetski list, broj 4, 279-290 - 117 - - 118 - STATUS OF EUVN AND EUVN_DA PROJECTS IN THE REPUBLIC OF CROATIA* Ilija Grgić, Bojan Barišić, Mihajla Liker ABSTRACT The EUVN points are represent one basic element of the European geodetic infrastructure. They serve as a control of the existing continental and national geoid solutions and for the estimation of height datum differences. After the first analysis, discrepancies between gravimetric geoid EGG97 and the point-wise EUVN geoid were detected due to errors in one of compared models. Croatian Geodetic Institute (CGI) received all materials related to EUVN project from the State Geodetic Administration. Analyse of the received materials shows that some height data, which have been sent to the EUREFUELN data centre, were calculated using benchmarks whose heights are in different height datum. This paper represents discrepancies between EGG97 and EUVN after using uniform new official height datum in Croatia – HVRS71 and densification project EUVN_DA on the territory of the Republic of Croatia. KEYWORDS EUVN, EUVN_DA 1. INTRODUCTION EUVN project was completed in the year 2001 under the EUREF responsibility. It consists of almost 200 points, which represent one basic element of the European geodetic infrastructure. EUVN points serve as a control of the existing continental and national geoid solutions in ETRS89 and for the estimation of height datum differences. After the first analysis, discrepancies between gravimetric geoid EGG97 and the point-wise EUVN geoid were detected due to errors in one of compared models. On the Croatian territory discrepancy on only one point, HR05-Split, exceeds 50 cm and that point is marked as problematic (Kenyeres et al. 2002), Fig. 1.1. +1cm +19cm +23cm +51cm +15cm +28cm <1dm >1dm +67cm 0cm 0 10 20 30 40 50 100 km Fig. 1.1. EGG97 and EUVN discrepancies on the territory of Croatia Need of solving these problems is recognised and defined in two EUREF resolutions: No. 3 (June 2000) and No. 4 (May 2001). Result is project of EUVN densification - EUVN_DA and its aim is solving the discrepancies problems and densification of EUVN points that will be used for sub-decimetre accuracy connection of different national height networks in Europe. In combination with new European Predstavljeno na EUREF2005 simpoziju (Symposium of the IAG Subcommission for Europe – EUREF) održanom u Beču, Austria, 2.-5.6.2005. godine. Objavljeno u Zborniku radova Simpozija (u tisku). * - 119 - gravimetric geoid it will contribute in analyses of the national levelling networks. Croatia, as member of EUREF, has been called to contribute in densification project. Priority of EUVN_DA project is realisation of dense and homogenous network of GPS/levelling points. Expected distances between points should be from 50 to 100 kilometres. Special attention should be given to areas where unexpected discrepancies are detected. New solution of European gravimetric geoid is in preparatory phase and it should be finished in 2006. This solution includes new terrestrial gravimetric data and improved satellite gravity models (CHAMP, GRACE). EGG2006 model and EUVN_DA points will be used in combination for the production of a sub-decimetre accuracy height reference surface consistent with ETRS89 and EVRS. 2. EUVN POINTS IN THE REPUBLIC OF CROATIA Existing EUVN points in Croatia are established within EUVN GPS campaign that was carried out 21-29 May 1997 under the Croatian State Geodetic Administration (SGA) responsibility. GPS measurements had been performed on 11 points but only 8 points became official EUVN points (Marjanović, Rašić 1998). HR07 HR01 HR06 HR09 HR02 HR10 HR04 HR08 Official EUVN station Additional EUVN station HR05 HR12 0 10 20 30 40 50 HR03 100 km Fig. 2.1. EUVN points established in 1997 GPS campaign 2.1. VERIFICATION OF CROATIAN EUVN DATA Croatian Geodetic Institute (CGI) was established after the EUVN GPS campaign had been finished. CGI received all data related to 8 official and 3 additional points with intention to make project of densification on Croatian territory. All official and additional points should have been connected by first order levelling to the nearest primary levelling network benchmarks. Levelling data were taken from the report “Preparatory works for participation of the Republic of Croatia in the European project - EUVN” (Čolić, 1997). For some points the CGI did not receive levelling data and for all points gravimetric measurements were not carried out. For this reasons full verification of EUVN data is not possible. Based on received data some works in suspected points should be repeated. Gravimetric measurements will be carried out at all points. This is the time when Croatia is replacing old vertical reference system (HVRS1875) with the new one (HVRS71). Accidentally in data centre were sent inhomogeneous levelling data. For points HR02 Brusnik, HR04 Gradište and HR08 Plitvice, used benchmarks heights were in old vertical reference system and for HR01 Bakar, HR03 Dubrovnik, HR06 Zagreb and HR07 Rovinj those heights were in new system. Because of missing data for point HR05 Split was impossible to find out which benchmark and system were used. Table 2.1.1. shows that discrepancies between EUVN and EGG97 were reduced after homogenisation of used benchmarks heights (Fig. 2.1.1.). Discrepancies at some points are higher than expectations so levelling will be repeated at points HR01 and HR07. Also measurements will be repeated at the point HR05. Connections of EUVN points with the official vertical network were completed in the same time with EUVN GPS campaign 1997. In the 2000 official data of Croatian vertical network integration in - 120 - UELN have been received (Feil, Rožić, 2000). Heights of all levelled points now should be expressed as UELN heights. Table 2.1.1. Discrepancies between EUVN and EGG97 geoid EUVN Point HR01 Bakar HR02 Brusnik HR03 Dubrovnik HR04 Gradište HR05 Split HR06 Zagreb HR07 Rovinj HR08 Plitvice Connec. Vert. ref. system Benchmar Homogenisatio of sent data n k 32 MXV A-496 6 FR3020 BP82 22264 HVRS71 HVRS71 HVRS1875 HVRS71 HVRS71 HVRS71 HVRS1875 HVRS71 Imposible to reconstruct HVRS71 HVRS71 HVRS71 HVRS71 HVRS1875 HVRS71 Diff. of benchmark heights [m] EUVN and EGG97 discrepancie from sent data [m] EUVN and EGG97 discrepancie after homogenisation [m] 0.0000 0.1468 0.0000 0.2589 0.51 0.19 0.00 0.23 0.67 0.01 0.15 0.28 0.51 0.04 0.00 -0.03 0.01 0.15 0.06 0.0000 0.0000 0.2152 +1cm +4cm -3cm +51cm +14cm +6cm <1dm >1dm +67cm 0cm 0 10 20 30 40 50 100 km Fig. 2.1.1. EGG97 and EUVN discrepancies after the homogenisation 3. DENSIFICATION ACTION EUVN_DA IN CROATIA Plan of densification completely rely on existing 8 official EUVN sites in Croatia. Three additional points that were measured in campaign 1997 will be included in densification because they have 7 days of GPS measurements and solid monumentation. Densification was planned with respects to geoid figure in region, suspicious EUVN and EGG97 discrepancies on official EUVN sites and present densification projects in neighbouring countries. To check coincidence of planned densification sites with specifications (expected distances between points should be from 50 to 100 kilometres), circles of 50 kilometres radius are drown, Fig. 3.1. Little parts of territory, between points HR06 and HR09 is not covered due to primary levelling network configuration and between points HR09 and HR14 due to Hungarian plan of densification. If Hungarian plan changes, there will be no significant impact on Croatian densification quality. In some areas network is denser than prescriptions because of more complex geoid figure in that parts. Official EUVN points and planned densification points create uniform network on the Croatian territory Fig. 3.1. In preparatory phase of densification action next works had been done (Grgić, Barišić 2004): • Project preparation, • Fundamental geodetic points data acquisition (benchmarks, gravimetric points, GPS and trigonometric points), • Production of data base that is necessary for densification planning, • Recognition and see over of potential sites. Except the planning of densification for the project realisation is necessary to do next works: - 121 - • GPS measurements on the points where needed and processing of measurements with a scientific software package according to the EUREF standards, • Connection of the points to the nearest UELN benchmarks by the first order levelling and measurements adjusting, • Gravimetric measurements on the all densification points because of the technically and scientifically correct estimation of the heights in geopotential and normal system of UELN, • Compilation of the official forms with the EUVN_DA points information, • Productions of technical report that will be send to the SGA. SI02 SI01 HR16 HR06 SI03 IT10 Hr9 HR02 HR14 HR01 Hr10 HR15 HR07 HR04 HR17 HR08 HR18 HR21 Official EUVN point Additional EUVN point Planned densification point HR19 HR20 HR05 HR22 Hr12 HR03 Fig. 3.1. EUVN and planned EUVN_DA points HR16 GPS m. levelling gravimetric m. site description 0 10 20 30 40 50 100 km Fig. 3.2. Planned works on the EUVN and EUVN_DA points - 122 - Existence of the solid monumentation and acceptable GPS, levelling or gravimetric measurements, vicinity of primary levelling network were major conditions for the selection of densification points. Examples of such points are HR19 Posedarje that is primary levelling network benchmark suitable for GPS measurements, HR21 Strmica first order gravimetric point suitable for GPS measurements in vicinity of the primary levelling network benchmark, HR16 Štefanovec with solid monumentation suitable for GPS measurements in vicinity of the primary levelling network benchmark Fig. 3.3. Fig 3.3. EUVN_DA points HR16 and HR 21 3.1. GPS, LEVELLING AND GRAVIMETRIC MEASUREMENTS On purpose to eliminate daily changes in height component, shortest period of measurements should be 24 hours. All GPS measurements will be carried out in accordance with the 1997 campaign specifications supplemented with the EUVN_DA recommendations (Torres, Kenyeres, 2002). Final solution coordinates will be delivered in ETRS89 system or ITRFyy frame. Additional information will be delivered in official forms. The EUVN_DA points will be connected to nearest primary levelling network benchmarks by the first order levelling. Because of the accuracy and economical aspects, EUVN_DA points are chosen close to the primary levelling network benchmarks. In the Republic of Croatia the fundamental gravimetric network was established few years ago. The network consists of 5 absolute gravimetric points and 36 points of the first order (Bašić et al., 2004). Gravimetric measurements are necessary for correct estimation of the EUVN_DA points heights in geopotential and normal system of UELN. The method of profiles, Fig. 3.1, will be used for gravimetric measurements. 1 2 3 4 5 Fig. 3.1. The method of profiles 4. CONCLUSION The project of densification - EUVN_DA in Croatia is result of systematic preparatory works. Planning of densification started after the CGI had received all materials related to the EUVN project. The project concerns requirements for sub-decimetre accuracy connection of different national height networks in region and for analyses of the national levelling network. Priority of the project is realisation of dense and homogenous network that will be used as base for future improvements of European geoid models. Some levelling data from EUVN 1997 campaign have to be corrected and gravimetric measurements on the all EUVN and EUVN_DA points have to be done. The national primary levelling network has been integrated within the UELN and prerequisite for estimation of the EUVN and EUVN_DA points heights in geopotential and normal system of UELN are satisfied. The densification project will improve next geoid models realizations on territory of Croatia and also clear misunderstandings of discrepancies at some official EUVN points. - 123 - REFERENCES Bašić, T., et al. (2004): Osnovna Gravimetrijska mreža Republike Hrvatske, Faculty of Geodesy, Zagreb. Čolić, K. (1997): Pripremni radovi za sudjelovanje Republike Hrvatske u europskom projektu “Europska vertikalna referentna mreža” (EUVN), Faculty of Geodesy, Zagreb. Čolić, K. Gojčeta, B. et al. (1997): EUVN 1997 GPS Campaign in Croatia, Faculty of Geodesy, State Geodetic Administation, Zagreb. Feil, L., Rožić, N. (2000): UELN geopotencijalni i normalni visinski sustav Republike Hrvatske, Faculty of Geodesy, Zagreb. Grgić, I., Barišić, B. (2004): Projekt progušćenja EUVN mreže (EUVN_DA), Croatian Geodetic Institute, Zagreb. Kenyeres, A., Ihde, J., et al. (2002): EUREF Action for the Densification of the EUVN Network, Presented at the EUREF Symposium in Ponta Delgada. Marjanović, M., Rašić, Lj. (1998): Results of the EUVN 1997 GPS Campaign in Croatia, Paper presented at the Second International Symposium Geodynamics of the Alps-Adria Area by means of Terrestrial and Satellite Methods, Dubrovnik. Torres, J. A., Kenyeres, A. (2003): Densification Action for the European Vertical Reference Network (EUVN_DA), EUREF form letter. - 124 - DIGITALNI ORTOFOTO U REPUBLICI HRVATSKOJ I U SVIJETU: NORME I STANJE U PRAKSI* Višnja Miloš SAŽETAK U ovom radu opisuju se teoretske postavke, način izrade i svrha prvih radova na području redresiranja, izrade fotoplana te ortofotoplana. Nakon teoretskih osnova dan je opis izrade digitalnih ortofotokarata danas, važeći pravilnici u Republici Hrvatskoj vezani uz njihovu izradu te pregled softvera i hardvera koji se danas koristi u izradi digitalnih ortofotokarata u Republici Hrvatskoj. Opisana su iskustva na izradi digitalnog ortofota i način prezentiranja izrađenih listova digitalne ortofotokarte na internetskim stranicama u nekim državama Europe i u Sjedinjenim Američkim Državama. Provedena su dva ispitivanja kvalitete digitalnih ortofotokarata u Republici Hrvatskoj. Prvim ispitivanjem trebalo je ustanoviti postoji li veza densitometrijskih vrijednosti zacrnjenja filma i vrijednosti histograma digitalnih zapisa pripadnih listova digitalne ortofotokarte. Drugim ispitivanjem, položajno se uspoređuju detalji preslikani na digitalnoj ortofotokarti i identični detalji na odgovarajućim listovima Osnovne državne karte/Hrvatske osnovne karte. Uz opis i ocjenu svakog pojedinog procesa izrade digitalne ortofotokarte dan je prijedlog na koji bi se način povećala njihova pouzdanost izrade i postigla bolja kvaliteta. Na kraju rada, dan je pregled nekih osnovnih i za fotogrametriju važnih novosti u načinu prikupljanja podataka, kao što su digitalne kamere za snimanje iz zraka, lidarski i radarski sustavi, GPSom (eng. Global Positioning System) podržano snimanje iz zraka, te satelitske snimke visoke rezolucije. ABSTRACT In this work the theoretical foundation, the purpose and the way of the first labors in the area of orthophoto production are described. After theoretical basics, the decription of the way of today´s production of orthophoto maps, the valid specificatons in the Republic of Croatia considering the orthophoto production, are given. Also, the review of the actual softwer and hardwer which is today in use in the Republic of Croatia, is illustrated. The following, is the decription of the experiances in the orthophoto production and the way of presenting orthophoto maps on the Internet sites in some countries in Europe and in the United States. Two investigations of the quality of the orthophoto maps in the Republic of Croatia are described. The aim of the first investigation was to check if there is connection between densitometric values of film density and the belonging histogram values of the digital orthophoto maps. With the second investigation, the position of the details on the digital orthophoto maps is checked against position of the coresponding details on the sheets of the Basic state map/Croation basic map. With description and the mark of each proces of the orthophoto production, the proposal how the accuracy and the quality of the digital orthophotos could be better, is given. At the end of this work, the overview of some basic and for photogrammetry important news in the way of collection data, like the digital camera for aerorecording, lidar and radar systems, the airborne GPS and satellite images of high resolution, are described. * Magistarski rad obranjen na Geodetskom fakultetu Sveučilišta u Zagrebu 25.11.2005. godine. - 125 - - 126 - POPIS AUTORA Autor Institucija Željko Bačić, prof. dr. sc. Državna geodetska uprava Republike Hrvatske Sjedište Zagreb Bojan Barišić, dipl. ing. geod. Hrvatski geodetski institut Zagreb Tomislav Bašić, prof. dr. sc. Geodetski fakultet Sveučilišta u Zagrebu Zagreb Stanislav Frangeš, prof. dr. sc. Geodetski fakultet Sveučilišta u Zagrebu Zagreb Ilija Grgić, mr. sc. Hrvatski geodetski institut Zagreb Željko Hećimović, dr. sc. Hrvatski geodetski institut Zagreb Slavko Lemajić, dipl. ing. geod. Hrvatski geodetski institut Zagreb Mihajla Liker, dipl. ing. geod. Hrvatski geodetski institut Zagreb Danko Markovinović, mr. sc. Geodetski fakultet Sveučilišta u Zagrebu Zagreb Višnja Miloš, mr. sc. Hrvatski geodetski institut Zagreb Stipica Pavičić, mr. sc. Hrvatski geodetski institut (do listopada 2004. godine) Zagreb Mladen Rapaić, dipl. ing. geod. Hrvatski geodetski institut (do studenog 2004. godine) Zagreb Nevio Rožić, prof. dr. sc. Hrvatski geodetski institut (do siječnja 2006. godine) Zagreb Ivica Vilibić, dr. sc. Institut za oceoanografiju i ribarstvo Split INDEX AUTORA I RADOVA Autor Članak Str. Bačić, Ž. Cambridge Conference 2003 "National mapping – shaping the future" Barišić, B. European vertical reference network (EUVN) considering Champ and Grace gravity models Metodologija određivanja crte srednjih viših visokih voda Status of EUVN and EUVN_DA projects in the Republic of Croatia 81 113 119 Bašić, T Status of the Croatian first order gravity network Visinska kontrola geodetskih i kartografskih proizvoda u procesu topografske i katastarske izmjere 33 101 47 Frangeš, S. Creating the toponymic database of the Republic of Croatia - project Toponimis as sub-project of Stokis Grgić, I. Specifičnosti geodetske osnove u tunelogradnji European vertical reference network (EUVN) considering Champ and Grace gravity models Visinska kontrola geodetskih i kartografskih proizvoda u procesu topografske i katastarske izmjere Kontrola kvalitete DOF-a u procesu katastarske izmjere Metodologija određivanja crte srednjih viših visokih voda Status of EUVN and EUVN_DA projects in the Republic of Croatia 71 81 101 107 113 119 Liker, M. Status of EUVN and EUVN_DA projects in the Republic of Croatia 119 Hećimović, Ž. Stabilnost mjernog sustava SCINTREX HGI-2 gravimetra Status of the Croatian first order gravity network European vertical reference network (EUVN) considering Champ and Grace gravity models Lemajić, S. Croatian-Norwegian geoinformation project Improvement of quality control system in Croatia Topographic data production as basis for NSDI – Croatian example Visinska kontrola geodetskih i kartografskih proizvoda u procesu topografske i katastarske izmjere Kontrola kvalitete DOF-a u procesu katastarske izmjere Markovinović, D. Stabilnost mjernog sustava SCINTREX HGI-2 gravimetra Status of the Croatian first order gravity network Miloš V. Kontrola kvalitete DOF-a u procesu katastarske izmjere Digitalni ortofoto u Republici Hrvatskoj i u svijetu: norme i stanje u praksi Pavičić, S. Topographic data production as basis for NSDI – Croatian example 91 Rapaić, M. Croatian-Norwegian geoinformation project Improvement of quality control system in Croatia Creating the toponymic database of the Republic of Croatia – project Toponimis as sub-project of Stokis Topographic data production as basis for NSDI – Croatian example 51 57 65 91 Rožić, N. Hrvatski geodetski institut Croatian geodetic institute Accuracy of geometric levelling networks at the terrritory of Croatia Točnost visinske osnove geometrijskog nivelmana na teritoriju Republike Hrvatske Status of the Croatian first order gravity network Strategy and system of QC of the official geographic data produced by private companies in Croatia Cambridge Conference 2003 "National mapping – shaping the future" Croatian-Norwegian geoinformation project Improvement of quality control system in Croatia Changes of bench mark heights being the consequence of introducing the new Croatian height system 7 9 11 25 33 41 47 51 57 73 Vilibić, I. Metodologija određivanja crte srednjih viših visokih voda - 127 - 65 17 33 81 51 57 91 101 107 17 33 107 125 113