TU1.L09.3 - Fully Polarimetric TerraSAR-X Data: Data Quality and Scientific Analysis

[email protected] 27-July-2010

Fully Polarimetric TerraSAR-X Data: Data Quality and Scientific Analysis

Irena Hajnsek1/2, Kostas Papathanassiou1, Thomas Busche1,

Thomas Jagdhuber1, JunSu Kim1, Maria Sanjuan Ferrer1, Stefan Sauer1,

Michelangelo Villano1

1Microwaves and Radar Institute & ²Institute of Environmental Engineering, ETH Zurich

TerraSAR-X: DRA Mode CampaignAnnouncement of Opportunity:

DRA Mode data available: simplified proposal procedure and free of charge !

Defined test site (over selected areas): 356 Data takes

Campaign duration: 3 cycles (33 days - April 11 and May 13, 2010)

StripMap mode (15 km swath width, 3 m resolution)

http://sss.terrasar-x.dlr.de

Selected Test Sites

At least 42 test sites with 3 repeat cycles (repeat pass Pol-InSAR)

Europe

North America

Arctic Sea

Transmit

Receive

Dual Receive Antenna Mode (DRA Mode)

Principle

Transmit: the full antenna is used

Receive: the antenna is ‚electrically‘ divided into two sections in azimuth direction (two independent receive channels are available)

TS-X Experimental Modes

Along-Track Interferometry (ATI)

Quad Polarisation

Mode Polarisation

TX H V H V

RX1 H H H H

RX2 V V V V

CH1 HH VH HH VH

CH2 HV VV HV VV

RX2RX1

GoalCommissioning Phase (2007)

Re-Calibration (2009)

Status

Internal Calibration

Temp Freeze- Amplitude- Phase

0.05 dB0.7°

< 0.05 dB< 0.7°

80 sec DT length< 0.05 dB< 0.9°

T/R Module Characterisation

Individual TRM Setting (1-σ):- Amplitude (Tx / Rx)- Phase (Tx / Rx)

--

0.38 dB / 0.56 dB5.3° / 2.6°

0.38 dB / 0.49 dB5.1° / 2.4°

Antenna Pointing Knowledge

Elevation 0.015° < 0.006° < 0.004°

Azimuth 0.002° < 0.002° < 0.001°

Geometric Calibration

Pixel Localisation Accuracy- Range- Azimuth

2 m2 m

0.30 m0.53 m

0.31 m0.54 m

Antenna Model Verification

Elevation Pattern Accuracy (two-way)

±0.2 dB < ±0.2 dB < ±0.2 dB

Azimuth Pattern Accuracy (one-way)

±0.1 dB < ±0.1 dBno measurements

Beam-to-Beam Offset- two-way over rain forest- one-way over ground receiver

±0.2 dB±0.1 dB

< ±0.2 dB< ±0.1 dB

< ±0.2 dBno measurements

Radiometric Calibration

Radiometric Stability 0.87 dB0.2 dB (after launch)

0.15 dB (2 years)

Relative Radiometric Accuracy 0.68 dB 0.31 dB 0.18 dB

Absolute Radiometric Accuracy

1.1 dB 0.6 dB 0.39 dB

TerraSAR-X Calibration Results

VVVH

HVHH

23

4

VVVH

HVHH

11

2

VVVH

HVHH

NN

NN

f

1

SS

SS

f

1)iexp(A

OO

OO

VVVH

HVHH

VVVH

HVHH

VVVH

HVHH

VVVH

HVHH

VVVH

HVHH

NN

NN

TT

TT

SS

SS

RR

RR

OO

OO

10

01

PP

PP

VVVH

HVHH

1X-Talk: On Receive: and

On Transmit: and Tx Channel Imbalance:

Rx Channel Imbalance:

System and Propagation Distortion Model

2

3 4

1f

2f

VVVH

HVHH

VVVH

HVHHT

VVVH

HVHH

VVVH

HVHH

VVVH

HVHH

VVVH

HVHH

VVVH

HVHH

NN

NN

TT

TT

PP

PP

SS

SS

PP

PP

RR

RR

OO

OO

Rx Distortion Tx DistortionScattererPropagation Propagation Add. Noise

2VVHHVV

2HV

VVHH2

HH

2VVHVVVHHVV

VVHV2

HVHHHV

VVHHHVHH2

HH

3

|S|0SS

0|S|20

SS0|S|

|S|SS2SS

SS2|S|2SS2

SSSS2|S|

:]C[

VVVH

HVHH

SS

SS:]S[ T

VVXXHHL4 ]SS2S[k

L3L33 kk:]C[

HVHVHHHH

HVHHHHHV

SSSS

SS:

VHVHHHHH

VHHHHHVH

SSSS

SS:

VHVHVVVV

VHVVVVVH

SSSS

SS:

HVHVVVVV

HVVVVVHV

SSSS

SS:

0!

2nd Order Descriptors:

HVHVVHVH

HVVHVHHV

SSSS

SS:

VVVVHHHH

VVHHHHVV

SSSS

SS:

1!

Polarimetric Coherences:

10 HHVV

Valid for Reflexion Symmetric Scatterers

)SS( VHHV

VHVH22VHVH32HHHH4VVHH22HVHH SSfSSfSSSSfSS

VHVH21VHVH31HHHH1VVHH31VHHH SSfSSfSSSSfSS

VHHV121VHVH4

21HHVV121VVVV32

21VHVV SSffSS|f|SSffSSf|f|SS

VH41HV12VV21HH1VV31VH1

HH4VV22HV2VH2HV3HHi

23

4

VVVH

HVHH

11

2i

SfSfSffSSfSf

SSfSfSSSAe

f

1

SS

SS

f

1Ae

VHHV121VHVH4

21HHVV421VVVV2

221HVVV SSffSS|f|SSffSS|f|fSS

0

0

Rx/Tx Distortion Matrices

Agricultural Test Site: Wallerfing (Germany)

Acquisition dates:

14 April 2010

25 April 2010

06 May 2010

14/04/2010

25/04/2010

06/05/2010

Subset of Wallerfing for 3 Different Dates @ Pauli RGB

Cross-Pol Ratios HV/VH

14/04/2010 25/04/2010 06/05/2010

14/04/2010 25/04/2010 06/05/2010

Polarimetric Coherence Histograms (Amplitude)

hhvv

hvvh

hhhv

vvvh

hhvv

hvvh

hhhv

vvvh

hhvv

hvvh

hhhv

vvvh

Polarimetric Coherences (Amplitude)

14/04/2010 25/04/2010 06/05/2010

Polarimetric Coherence Histograms (Phase)

hhvv

hvvh

hhhv

vvvh

hhvv

hvvh

hhhv

vvvh

hhvv

hvvh

hhhv

vvvh

Polarimetric Coherences (Phase)

SNR Estimation:

VVVH

HVHH

VVVH

HVHH

VVVH

HVHH

NN

NN

SS

SS

OO

OO

HVHVVHVH

HVVHVHHV

SSSS

SS: 1

!

XXVHHV SSS

XX

XX

XXXX

HVHVVHVH

HVVHVHHV

SNRNS

SS

OOOO

OO1

1

1

||||:

22

Reciprocity:

SNR Estimates from HVVH Coherence

SNR Estimates from hvvh Coherence14/04/2010 25/04/2010 06/05/2010

Polarimetric SAR for Different Applications: Examples

Wallerfing (Agriculture)

Change of polarimetric feature depending on crop phenology

Repeat pass Pol-InSAR coherence analysis

San Francisco (Urban Area)

Urban area application for feature separation and interpretation

Argentiere & Aletsch (Glaciers)

Coherent Scatterer detection

Ward Hunt Ice Shelf (Sea Ice)

Change of sea ice feature

Dates Winter Wheat Sugar Beet

VV>HH HH>VV VV>HH HH>VV

14/04/2010 44.2% 55.8% 51.4% 48,6%

25/04/2010 37.9% 62.1% 39.0% 61.0%

06/05/2010 17.8% 82.2% 49.1% 50.9%

14/04/2010 25/04/2010 06/05/2010

Polarimetric Ratios HH/VV @ X-band

Entropy/Alpha Angle @ X-band

14/04/2010 - Entropy 25/04/2010 - Entropy 06/05/2010 - Entropy

Entropy/Alpha Entropy/Alpha Entropy/Alpha

Interferometric Coherences @ Different Polarisations

|HV12|

|SHV1| ||SHV1|-|SHV2||

|VV12|

|SVV1| ||SVV1|-|SVV2||

|HH12|

|SHH1| ||SHH1|-|SHH2||

April 25th - May, 6thApril 14th - May, 6thApril 14th - April, 25th

San Francisco (11/04/2010)

2

π

Alpha_1

0

Double-bounce

Single-bounce

Triple-bounce

Double-bounce

Polarimetric TSX Image of the Golden Gate Bridge

Coherent Scatterers (CSs) Detection

Method: Phase Variance ApproachBased on the deterministic phase pattern across the spectrum characteristic of the CSs.

It allows a widely preservation of the spatial resolution in the CSs detection.

Common detection: Only the CSs that have a phase derivative variance σ² lower than a given threshold in both directions (range and azimuth) are considered as detected CSs.

10 sublooks of 60 MHz each out of the 150 MHz range bandwidth are formed and the variance σ² of the phase derivative for every pixel is estimated.

10 sublooks of 552 Hz each out of the 1380 Hz azimuth bandwidth and the variance of the phase derivative for every pixel is estimated.

Fixing a threshold (σ² ), pixels with a phase derivative variance lower than the threshold in range and azimuth at the same time will be considered as a detected CSs.

CSs Detection on the Argentiere Glacier (France)

CR

CR

CR

σ²=0.0025 rad²

σ²=0.0064 rad²

σ²=0.0144 rad²

CR

IM (13-04-10)

Argentiere Glacier (France): Coherent Scatterer Detection

IM1 (13-04-10)IM2 (24-04-10)IM3 (05-05-10)

σ²=0.0081 rad²

Aletsch Glacier (Switzerland): Coherent Scatterer Detection

2010/04/13

Pauli RGB Composites

2010/04/242010/05/05

Ice Shelf

Land Fast Ice

Pack Ice

Ward Hunt Ice Shelf

RadarSAT-2 Blue line 2001Red line 2008

Eastern Ward Hunt ice shelf showing long (up to 15 km) meltwater lakes that form every summer on the ice surface.

-ää

(http://madzu.com/ellesmere/Ward_Hunt.html)

TU1.L09.3 - Fully Polarimetric TerraSAR-X Data: Data Quality and Scientific Analysis

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Transcript of TU1.L09.3 - Fully Polarimetric TerraSAR-X Data: Data Quality and Scientific Analysis