Finding and Interpreting NGS Datasheets

Finding and Interpreting NGS
Datasheets
Finding a datasheet from the NGS
website (www.noaa.ngs.gov)
Click on
Survey Mark
Datasheets
Navigating the site
Click on
Datasheets
Navigating the site
Learn more about
datasheets
If you already know
the PID identifier
If you already know the
project coordinates. Very
helpful for GPS calibration
Search with a map
If you are using Lat/Long and Radius
• Need to know coordinates of the base point
– Can be Lat/Long
• Can be DMS or Decimal Degrees
– Can be SPC (meters only)
• You can find Lat/Long from other websites
using a street address
– Try www.batchgeo.com
– You can use Google Earth also
Select Input Type and Radius
GPS Only if this
is for GPS
calibration
Using Lat/Long and Radius
Indicates radial
distance to the site in
miles
Navigating the site
Learn more about
datasheets
If you already know
the PID identifier
If you already know the
project coordinates. Very
helpful for GPS calibration
Search with a map
Using the map search
• Requires the use of popup windows
• You will need to allow popups on your
computer to use the map search
Using the map search (test popups)
Using the map search
Use the navigation tools
to zoom in on the
desired area
Using the Map Search
Click here
Scale bar must
be less than 5
miles long
Control Points are designated by a
random number
2
3
Select the desired point(s) and click
Get Datasheets
What Does a Datasheet Tell me?
• Permanent Identifier (PID)
• Lat/Long
• Height
– Orthometric (from MSL)
– Ellipsoid Height (only on GPS points)
• Other Coordinates
– SPC (State Plane Coordinates)
– UTM (Universal Transverse Mercator)
– Geocentric (X,Y,Z) for GPS points only
What Does a Datasheet Tell Me?
• Description of what kind of marker is at the
point
• History of monumentation
• Descriptions of how to navigate to the marker
location
Control Point DH5542
Height is measured by GPS observation to
is
DH5542 PID - DH5542
the closest centimeter (314.66m), which
DH5542 STATE/COUNTY- WI/WOOD
DH5542 USGS QUAD - WISCONSIN RAPIDS SOUTH (1984)
1032.347ft, but must be rounded to
DH5542
1032.3ft because the original
DH5542 *CURRENT SURVEY CONTROL
DH5542
measurement was only to centimeter
___________________________________________________________________
level. Referenced to NAVD88 datum
DH5542* NAD 83(2007)- 44 22 22.38978(N) 089 46 13.21963(W) ADJUSTED
DH5542* NAVD 88 - 314.66 (meters) 1032.3 (feet) GPS OBS
DH5542
___________________________________________________________________
DH5542 EPOCH DATE - 2002.00
Geocentric (X,Y,Z) Coordinates
DH5542 X - 18,305.246 (meters) COMP
DH5542 X - 18,305.246 (meters) COMP
DH5542 Y - -4,566,760.369 (meters) COMP
DH5542 Z - 4,437,997.885 (meters) COMP
DH5542 Y - -4,566,760.369 (meters) COMP
DH5542 LAPLACE CORR- -5.47 (seconds) DEFLEC09
DH5542 Z - 4,437,997.885 (meters) COMP
DH5542 ELLIP HEIGHT- 279.314 (meters) (02/10/07) ADJUSTED
DH5542 GEOID HEIGHT- -35.34 (meters) GEOID09
DH5542
DH5542 ------- Accuracy Estimates (at 95% Confidence Level in cm) -------DH5542 Type PID Designation North East Ellip
DH5542 ------------------------------------------------------------------Ellipsoid height is 279.314m
DH5542 NETWORK
Geoid Undulation is -35.34m when
DH5542 GRAND RAPIDS C GPS 0.29 0.24 0.49
DH5542 ------------------------------------------------------------------referenced to GEOID09
DH5542
Orthometric height is
279.314m-(-35.34m)=314.654m
Control Point DH5542
DH5542.The horizontal coordinates were established by GPS observations
DH5542.and adjusted by the National Geodetic Survey in February 2007.
DH5542
DH5542.The datum tag of NAD 83(2007) is equivalent to NAD 83(NSRS2007).
DH5542.See National Readjustment for more information.
DH5542.The horizontal coordinates are valid at the epoch date displayed above.
DH5542.The epoch date for horizontal control is a decimal equivalence
DH5542.of Year/Month/Day.
DH5542
DH5542.The orthometric height was determined by GPS observations and a
DH5542.high-resolution geoid model using precise GPS observation and
DH5542.processing techniques.
DH5542
DH5542.The X, Y, and Z were computed from the position and the ellipsoidal ht.
DH5542
DH5542.The Laplace correction was computed from DEFLEC09 derived deflections.
DH5542
DH5542.The ellipsoidal height was determined by GPS observations
DH5542.and is referenced to NAD 83.
DH5542
DH5542.The geoid height was determined by GEOID09.
DH5542
DH5542;
North
East
Units Scale Factor
Converg.
DH5542;SPC WI C - 59,979.959
618,304.087 MT 0.99997904 +0 09 43.4
DH5542;SPC WI C - 196,784.25
2,028,552.66 sFT 0.99997904 +0 09 43.4
DH5542;UTM 16 - 4,917,022.888 279,284.331 MT 1.00019914
-1 56 17.3
DH5542
DH5542! –
Elev Factor x Scale Factor
= Combined Factor
DH5542!SPC WI C - 0.99995621 x 0.99997904
= 0.99993525
DH5542!UTM 16 - 0.99995621 x 1.00019914
= 1.00015534
Explains observation methods
and datum references
State plane coordinates in both
meters and feet, UTM
coordinates, scale factor, and
convergence (units in DMS)
Combining horizontal and
elevation scale factors