Electromagnetic modelling and Signal Analysis

C.S.L
Liege Science Park
Avenue du Pré-Aily
B-4031 ANGLEUR
Belgium
Tel: +32.4.382.46.00
Fax: +32.4.367.56.13
Electromagnetic modelling
and Signal Analysis
Christian Barbier
GALAXIA May 05, 2011
CSL
Who’s Who
Anne Orban
Dominique Derauw
Christian Barbier
Aline Hermans
GALAXIA May 05, 2011
Joseph Bernier
CSL
Advanced Technologies Department
J.H. Lecat
Electromagnetic Modelling and Signal Analysis Group
C. Barbier
SAR Processing
C. Barbier
D. Derauw
A. Orban
A. Hermans
Projects :
6 ESA
1 Belspo
2 RW
GALAXIA May 05, 2011
InSAR/DInSAR
PolSAR/PolInSAR
UAV’s
D. Derauw
A. Orban
A. Orban
D. Derauw
C. Barbier
Projects :
1 ESA
12 Belspo
Projects :
2 Belspo
Hyperspectral
Remote
Sensing
Industrial
valorization
C. Barbier
J. Bernier
C. Barbier
A. Orban
Projects :
1 FP6
Projects :
2 RW
1 industrial
CSL
Radar Remote Sensing
GALAXIA May 05, 2011
CSL
What Is Radar?
RADAR = RAdio Detection And Ranging
Transmitter
Receiver
R
Distance : R = cDt/2
Information in :
Signature : s
GALAXIA May 05, 2011
CSL
Two specificities of radar :
Observations
night and day.
all-wheather.
GALAXIA May 05, 2011
CSL
Aspects of radar remote sensing
GALAXIA May 05, 2011
CSL
POST-PROCESSING
Thematic products
Focused
SAR images
USER
PRE-PROCESSING
Ground Station
Cordoba
Redu?
GALAXIA May 05, 2011
Broadcasted
SAR raw data
CSL
Topics 1 :
Radar Imaging
GALAXIA May 05, 2011
CSL
Illustration of radar image reconstruction. The raw image is shown on the left, as it is received from the
ERS-1 satellite orbiting at an altitude of 800 km. The reconstruction process results in the focussed image
shown on the right, which has a spatial resolution of about 10 meters (ESTEC Contract No
GALAXIA
May 05, 2011
CSL
11370/95/NL/FM
"Scalable Processor for Ground Segment").
Buenos Aires from
Space
ERS raw data
Cordoba ground station
CSL processor
GALAXIA May 05, 2011
CSL
A medium-resolution (300 m) image, reconstructed by one of the CSL processors from a raw image acquired by
the SIR-C radar on Space Shuttle Endeavour at an altitude of 221 km. This image covers an area of 250 km x
250 km located in Oklahoma Oklahoma (ESTEC Contract No 11757/95/NL/FM(SC) "Advanced Algorithm
Techniques (ScanSAR Algorithms))".
GALAXIA May 05, 2011
CSL
Partnerships Examples
Topics
Candidate partners
SAR image processing
and distribution
Agencies, institutions
SAR processors
Software industry
GALAXIA May 05, 2011
CSL
Topics 2 :
Advanced Radar Processing
GALAXIA May 05, 2011
CSL
SAR INTERFEROMETRY (InSAR)
Full-resolution SAR images are complex-valued :


amplitude
 classical SAR imagery
phase
 optical path (geometrical +
atmospheric effects) + backscattering
If the scene has not changed between the two
acquisitions and if the two images remain correlated, the
phase difference is purely topographical.
Pass 1
Pass2
 Possibility to generate Digital Terrain Models
(DTMs).
Interference pattern
GALAXIA May 05, 2011
CSL
II.1 SAR INTERFEROMETRY (InSAR) (2)
A relief map of the Liège region, obtained by applying the interferometric technique to one ERS-1 image and one ERS-2 image
(ESRIN Contract Nr. 12159/96/I-HGE "Quality Assessment of InSAR Topographic Mapping").
GALAXIA May 05, 2011
CSL
LIÈGE SOUS L’OEIL DU RADAR SPATIAL
© ESA
Depuis une altitude de 785 km, les
radars embarqués sur les deux
satellites ERS réalisent des images
de la surface terrestre avec une
résolution au sol de l’ordre de 30 m.
LIÈGE
N
Composition colorée
réalisée à partir d’une image
SPOT (XS) drapée sur le modèle
numérique de terrain.
LIÈGE
Composition
colorée réalisée à
partir de l’image
radar et du MNT.
© CNES-1992 Distribution SPOT Image
Laboratoire SURFACES
Département de Géomatique
Université de Liège
GALAXIA May 05, 2011
Centre Spatial
de Liège
CSL
A relief map of the Jordan coast, obtained by applying the interferometric technique to one ERS-1 image
and one ERS-2 image. The Dead Sea can be seen on the left-hand part. This map covers an area of 50 km
x 50 km (SSTC Contract No T3/12/012 "Neotectonic Study in Hill and Mountain Countries : an
Interferometry Application").
GALAXIA May 05, 2011
CSL
InSAR - Coherence
• InSAR Coherence is a
measurement of the
“quality” of the
interferometric signal
– Any scene changes
between SAR acquisition
induces Coherence
losses
– These information losses
provide information on
how the scene is
changing as a result of
human activity,
vegetation density, crop
stage, etc
GALAXIA May 05, 2011
CSL
SAR DIFFERENTIAL INTERFEROMETRY (DInSAR)
Possibility to measure surface changes
component.
by removing the topographical
A spectacular result of radar interferometry : the interference pattern reflects the terrain displacements due
to the Landers (California) earthquake in June 1992. Displacements of only 28 mm can be detected
despite of the altitude (800 km) from which the images were acquired. The fracture fault can be seen on
the right, where the fringe density is the highest. This interferogram covers an area of 50 km x 50 km
(SSTC Contract No T3/12/012 "Neotectonic Study in Hill and Mountain Countries : an Interferometry
Application").
GALAXIA
May 05, 2011
CSL
Potential application fields :
Earthquakes monitoring
Volcanoes
Terrain subsidence
Glaciers
Crop monitoring
….. Change monitoring
GALAXIA May 05, 2011
0
[m]/[jour]
9
Coherence tracking measurements of the Shirase glacier, a fast
flowing ice stream in Antarctica. The amplitude of the
measured displacements are shown on the left. A vectorial
representation is given on the right.
CSL
SAR POLARIMETRY (PolSAR)
PolSAR provides
scattering mechanisms
information.
V
H
.

k


Vegetation cover
 
Uint  .E
GALAXIA May 05, 2011
Soil
CSL
Quad-polarimetric processor
HH
VV
HV
Co-located antennas: HV = VH.
All the images presented in these slides have been produced at CSL, using raw data provided by DLR .
GALAXIA May 05, 2011
CSL
POLARIMETRIC INTERFEROMETRY (PolInSAR)
InSAR  height information.
PolSAR  scattering mechanisms information.
PolInSAR  height distribution of scattering mechanisms
GALAXIA May 05, 2011
CSL
A 3D model of a forest
GALAXIA May 05, 2011
CSL
Cultivated area
Vertical cut through the differential interferogram .
For the observed areas, we can see variations of the order of
3 or 4 radians, corresponding to about 15 cm.
GALAXIA May 05, 2011
CSL
Partnerships Examples
Topics
Digital terrain models
Displacement / change maps
InSAR/DInSAR processors
GALAXIA May 05, 2011
Candidate partners
NGI, regional institutions
(cartography, environment,
security), MoD, NGO, game
industry (flight simulators)
Regional and local institutions
(cartography, environment,
security), MoD,insurance
companies (terrain
subsidence)
Software industry
CSL