Download - NRSC RISAT 1 Data Format 2.pdf
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
RISAT-1 Data Processingby
Santanu [email protected]
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
Beam Mode
Level of
Processing
Look Angle(Deg)
NominalScene size
Azimuth* Range (km)
Azimuth/ RangeNo of Looks
Azimuth/ Range
Resolution(m)
(with weighting)
Azimuth/Range
Sampling(m)
FRS1
L1SLC 11-49 25*25 1/1 3.3/2.2 2.3/1.8
L1GR11-24 25*25 4/2 13/22 – 10.6 9.2/9
24-49 25*25 4/2 13/10.3 – 5.6 4.6/4.5
L211-24 25*25 4/2 13/22 – 10.6 9.2/9
24-49 25*25 4/2 13/10.3 – 5.6 4.6/4.5
FRS2 L1SLC 11-49 25*25 1/1 10/4.68 4.6/3.6
MRS
L1SLC 11-49 115*115 1/1 23-25/8.8 14.2/7.2
L1GR11-22 115*115 1/1 24/45-22 13.8/1823-49 115*115 1/2 24/43-22 13.8/18
L211-22 115*115 1/1 24/45-22 18/1823-49 115*115 1/2 24/43-22 18/18
CRS
L1GR11-34 223*223 1/3 48/135-46 27.6/3634-49 223*223 1/4 48/60-45 27.6/36
L211-34 223*223 1/3 48/135-46 36/3634-49 223*223 1/4 48/60-45 36/36
RISAT-1 PRODUCT SPECIFICATIONS
Parameter Accuracy
Geo location
accuracy (RMSE)
750 m
(For plain areas)
Geometric Distortion
Meters FRS1 - 100 MRS - 150CRS - 300
Radiometric
Resolution (SLC)3.1 dB
PSLR -17 dB
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
RISAT-1 Data Processing Work Flow
Near Real Time Processing for FRS-1, FRS-2, MRS and CRS mode data
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
Imaging Mode
RAW
(CEOS)
L1-SLC
(CEOS)
L1-Ground Range
(CEOS)
L2-Geo Referenced
(CEOS & GeoTIFF)
(Proj: UTM & Polyconic)FRS-1 Available Available Available AvailableFRS-2 Available Available Not Applicable Not ApplicableMRS Available Available Available AvailableCRS Available Under
EvaluationAvailable Available
SAN,metadata
server
DP Scheduler System 8 core, 4 GB RAM, 2.83 GHz
SWITCH
4Gbps each
Level-0 SystemOpteron 8356 series
4-CPU 8-Core Server, 32 GB RAM, 2.66 GHz, (Xeon x7460 based)
6X Image Formation
RISATCluster
0
5 0
1 0 0
1 5 0
2 0 0
2 5 0
3 0 0
Tim
e in
sec
onds
1 2 4 8 16
RISAT-1 Data Processing System Architecture in IMGEOS
MODE SCENE ACQUISITION TIME
SCENE PROCESSING
TIME(Raw data to L2 GeoTiff )
FRS-1 ( 30 km)
4.6 sec 15
FRS-2 (30 Km)
4.6 sec 45
MRS(115 Km)
17.5 sec 55
CRS (230 Km)
32.8 sec 120
Data Processing Time in IMGEOS
Data Products Availability for various modes
PolarisationHH, HV, VV, VH, RV,RH
Product LevelsLevel-0 RAW Level-1 SLCLevel-1 Ground
RangeLevel-2 Terrain
Geocoded
RISAT-1 Data Processing
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
Range variation of Different Targets
698092698093698094698095698096698097698098698099698100
0 1000 2000 3000 4000 5000
azm sample
rang
e (m
) nr_azmmid_azmfar_azm
Stripmap Mode SAR
t-a/2
ta/2
Tnr
Tmid
Tfar
t0
RtR0
Targets at different
Azimuth positions
Frequency Characterictic of Different Targets
-1500
-1000
-500
0
500
1000
1500
0 1000 2000 3000 4000 5000
azm sample
freq
uenc
y (H
z)
nr_azmmid_azmfar_azm
Characteristic of Range Migration
01234567
-1500 -1000 -500 0 500 1000 1500
frequency (Hz)
del_
rng nr_azm
mid_azmfar_azm
Targets with identical range minimum have the same frequency modulation rates. Targets follow a common trajectory in
frequency domain
Frequency characteristics
-1500
-1000
-500
0
500
1000
1500
0 1000 2000 3000 4000
azm sample
freq
uenc
y (H
z)
nr_rngfar_rng
Tnr
Tmid Tfar
Targets at different Range positions have different frequency modulation rates and
do not follow the same trajectory in frequency domain
Targets at different Range positions
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
Stripmap Mode SAR
49505152535455
0 1000 2000 3000 4000
Azimuth Samples
Ran
ge S
ampl
es
Quad rcmlinear Interpol.FFT interpol.
2D Echo Signal Range Compression
Fully Focused
Range Cell Migration Correction
Range Compression – Cross-correlate data with replica in the range direction
Azimuth Compression - Construct a chirp with a required fm rate & Cross-correlate the RCM corrected signal with the chirp
C hirp S ignal
-1
-0.5
0
0.5
1
1778 1978 2178 2378 2578 2778 2978
sa m ple
Rea
l pt
Replica Signal Matched Filtering
Response Signal
-100
0
100
200
300
400
500
600
700
800
1950 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050
sample
Am
plitu
de
Pulse Compression
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Stripmap Mode SAR Processing
f
compress detect & addcompress
Single look Multi look
SAR Raw Echo Data Range Compression
Single Look Image Multi Look ImageOne of four Looks
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FRS1 Stripmap mode Images
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ScanSAR Mode SAR
Azimuth 1
23
4
7
Ran
ge
sw6sw5sw4sw3sw2sw1
45
6
Azimuth
Ran
ge
beam0 Signal Processed
burst k
burst k+1
burst k+2
Processing of one ScanSAR beam
BlendedBursts
ScallopCorrected
Radiometric Corr.
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ScanSAR Mode SAR
bm0 bm1 bm2 bm3 bm4 bm5Signal Processed ScanSAR beams
Mosaiced ScanSAR Ground Range dataCorrected ScanSAR beams
bm0 bm1 bm2 bm3 bm4 bm5
Azimuth Variations Range Variations Terrain Geo-coded Product
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RIS
ATR
adar
sat-2
MysoreHomalinWest Homalin
MRS ScanSAR Images
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Azimuth BWFilter 1Filter 2Filter 3Filter 4
Range
Azi
mut
h
VV VH HV HH
Alternate Polarization Mode SAR
HH/HV
VV/VHHH/HV
Burst Signal
C h i r p o f S t r ip m a p m o d e
- 1 .5
- 1
- 0 .5
0
0 . 5
1
1 . 5
0 5 0 0 1 0 0 0 1 5 0 0 2 0 0 0 2 5 0 0 3 0 0 0
s a m p le
real
par
t
R es p o n se o f S tr i p m a p m o d e
-1 0 0
-9 0
-8 0
-7 0
-6 0
-5 0
-4 0
-3 0
-2 0
-1 0
033 00 3 31 0 3 32 0 33 30 3 34 0 3 35 0 33 60 3 37 0 3 3 80 33 9 0 3 40 0
S a m p le
Am
plitu
de (d
B)
Compression of Continuous Signal C h i r p o f B u r s t m o d e
- 1 - 0 . 8 - 0 . 6 - 0 . 4 - 0 . 2
0 0 .2 0 .4 0 .6 0 .8
1
0 5 0 0 1 0 0 0 1 5 0 0 2 0 0 0 2 5 0 0 3 0 0 0
S a m p l e
R ea l p ar t
R e s p o n s e o f B u r s t m o d e
- 4 0
- 3 5
- 3 0
- 2 5
- 2 0
- 1 5
- 1 0
- 5
03 3 0 0 3 3 1 0 3 3 2 0 3 3 3 0 3 3 4 0 3 3 5 0 3 3 6 0 3 3 7 0 3 3 8 0 3 3 9 0 3 4 0 0
S a m p l e
Am
plitu
de (d
B)
Compression of Burst SignalSignal Memory
Filter 1 o/p
Filter 2 o/p
Filter 3 o/p
Filter 4 o/p Stitched o/p
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FRS-2 Image Hirakund FRS-1 RV + RH Image Ahmedabad
RISAT Polarimetric Images
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SAR Geolocation Algorithm
Attitude
λ,фOptical P/L
Geolocation Algorithm
Ellipsoid/DEM
InputScan,Pix
Orbit
SAR Geolocation
Algorithm
Doppler Centroid Orbit
InputScan,
PixEllipsoid/DEMInitial
GuessScan, Pix
Range
λ,ф
Azimuth
Beam Center
SAR
A
D
B
C
Range
A
C
B
D
Zero Doppler Processing
Range
Azimuth
D C
B A
SAR signal space
SAR image space
Iso-Range Contours
Iso-Doppler Contours
ispjmr r
.0
Range Equation :
isp
ispispjifDC
.2,
Doppler Equation :
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
Use of DEM for Antenna Pattern Correction & Geo-location Improvement
Swath Selection in Product & Radiometric Correction using antenna Pattern & DEM
Geo-location Improvement using DEM
Without Antenna Pattern Correction With Ant Pat Corr. and no DEM With Ant Pat Corr. and DEMApplication of DEM ensures appropriate swath selection and correct radiometric correction
L1 Gnd Rng ImageLoc Acc < 300 m
DEM FieldEllipsoidal Ht : 3 to 5 Km L2 Terrain Geocoded Image
with true height Loc Accuracy < 300 m
L2 Terrain Geocoded Image with average height Loc
Accuracy < 1.5 Km
Distortion due to foreshortening &
Layover
No Distortion
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
MRS – India Mosaic
Development of Software for INDIA Mosaic : 100 m sampling 1. Registration 2. Radiometric Balance
Future Product Operationalization – Speckle Reduced Products / Polarimetric Products / Mosaic Products / Multi-Temporal Registered Products / Optical-SAR Fused Products
HH Pol HV Pol
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
Analysis of Point Target Response
SAC/Ahmedabad NalSarovar
ShadnagarNarkhodaCorner Reflectors have been deployed and FRS-1 SLC images have been evaluated for geometric resolution 3m ( wt 0.9 ) / 3.25 m ( wt 0.7) in azimuth & 2.0 m ( wt 0.7) in range with adequate PSLR & ISLR
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
Payload Characteristics
Platform Characteristics :
Payload & Platform Characteristics
Health of Raw Echo Data is excellent
-120.00
-100.00
-80.00
-60.00
-40.00
-20.00
0.000 10 20 30 40
FDC
Val
ue (I
n H
z)
Scene Number
FDC Vs Scene No (Dumping Orbit-326 Polarization-RV)
Azimuth
T
beam centre
closest
approach
tant_peak
tzero_dopp
Excellent Yaw Steering Resulting in low Doppler Centroid Estimates
DQE Package is installed at NRSC1. Geometric DQE Package2. Radiometric DQE Package3. Raw Data Analysis Package4. Point Target Analysis Package5. Onboard Calibration Package
DQE Operational Package
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
VV
VH
RV
RH
Radiometric Accuracy
Amazon Statistics HH : -6.47 ± 0.71 dB VV : -6.11 ± 0.23 dB1. Estimation of Distribution of Sigma Naught2. Evaluation of Radiometric Correction Procedure3. Estimation of Minimum Sigma Naught Parameter
Radarsat-1 : Absolute Radiometric Accuracy : 3 dBRadarsat-2 : Absolute Radiometric Accuracy : 1 dBRISAT-1 : Relative Radiometric Accuracy : 1 dBRISAT-2 : Absolute Radiomeric Accuracy : 2 dB
HH
HV
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
RISAT Data Extraction & Display Package
RISAT Data Extraction Package in Linux & Windows
Image Display & Display of Meta Data & Auxiliary Files
Feb 2013 RISAT-1 Data Processing NRSC User Interaction Meet SIPA/SAC
THANK YOU