TerraSAR-X: Status Report & Polarimetric Data...

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Folie 1irena.hajnsek@dlr.de - 25.01.2007

TerraSAR-X: Status Report & Polarimetric Data Exploitation

Alberto Moreira & Irena HajnsekGerman Aerospace Center (DLR)Microwaves and Radar Institute

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TerraSAR-X: A National Science Mission withCommercial Potential

DLR- Project Management- G/S Development & Ops- Science Coordination

Infoterra- Service Infrastructure- Information Products- Commercial Exploitation

Public Private Partnership

Main Mission Goals:• Provision of TerraSAR-X data for scientific applications public interest• Commercial exploitation of TerraSAR-X data by industry

EADS Astrium- Platform Development- Instrument Development- Launch on Dnepr (2006)

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Application of SAR PolarimetryAgriculture/Land-Use (+++)

Crop classificationPlant moisture contentCrop conditionCrop yield

Forestry (+)Forest typeForest structure (horizontal)Clear cuts/Fire-scars

Geology (++)Geological structuresLava flows Weathering erosion studiesSurface roughness

Hydrology (++)Soil moistureSnow hydrologyWetlandsFlood mapping

Oceans (+++)WavesCoastal zonesShips detection

Sea / Land Ice (++)Sea ice edge & ice concentrationIce topography/structurePolar glaciology

Meteorology (+)Rain rate estimationWater/ice particle studiesSevere storm/ Flood warning

Cartography/ Urban Area (++)Direct surface slope estimationCartographic feature extractionUrban Area characterisation

Disasters (++)FloodsGeological hazardsOil spillsSearch & Rescue

(+++/high) (++/medium) (+/low) SAR Polarimetry is recommended

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center frequency 9.65 GHz (X-band)Tx bandwidth up to 150 MHz (300 exp.)PRF 3 KHz to 6,5 KHztransmit duty cycle 13-20%radiated peak power 2260 Wsystem noise figure 5 dB

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antenna dimension in azimuth 4.784 mantenna dimension in elevation 0.704 mazimuth beamwidth 0.33°elevation beamwidth 2.3°scan angle azimuth ± 0.75°scan angle elevation ± 19.2°

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TerraSAR-X Orbit

sunlight sidenight side

dusk/down orbitaltitude at equator 514.8 km inclination 97.44°sun-synchronous repeat orbit:repeat period 11 daysrevisit time 4.5 days (100%)

2.5 days (95%)orbits per day 15 2/11

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TerraSAR-X Mission Profile

X-Band Downlink@ 300 Mbit/sec

DLR GS Neustrelitz

S-BandTM & TC

Mission OperationsDLR Oberpfaffenhofen

Raw Data Acquisition

DLR GS Weilheim

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Stripmap Mode

ScanSAR Mode

Spotlight Mode (Sliding)

HighRes Spotlight Mode (Sliding)

TerraSAR-X Imaging ModesFlight direction

Nadir Track

45°

20°

SwathWidth100 km

Stripmap ScanSAR Spotlight HighRes Spotlight

full perf. inc, angle range 20° - 45° 20° - 45° 20° - 55° 20° - 55° scene size along track acqu. length acqu. length 10 km 5 km scene size ground range 30 km 100 km 10 km 10 km single look az. resolution 3 m 16 m 2 m 1 m single look range resolution 3 m (ground) 16 m (ground)

@ 5 looks 1.2 m (slant) 1.2 m (slant)

Centre of rotation

Θ1=20o Θ2=55o

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TerraSAR-X Mission

Space Segment

Satellite Bus SAR Instrument

Ground SegmentMission Operations

SegmentIOCS - Instrument Operations

& Calibration SegmentPayload Ground

Segment

Science Users

Commercial Service SegmentScience Service Segment

Commercial Users

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Transmit Receive

Ocean CurrentsTarget Velocities

Dual Receive Antenna Mode

ATI Evaluation of STRM Data, IMF

Traffic jam on A96 near GermeringESAR data analysed by S. Suchandt, IMF

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Dual Receive Antenna Mode

Tx: H V H V

Rx: H V H V H V H V

Two-way (Tx-Rx): HH HV VH VV HH HV VH VV

Transmit Receive

the antenna is electrically divided into 2 receiving antennasthis enables full-polarimetric operation and along track interferometry

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Polarization ModesH H H H

H H H H

Transmit

Receive

Single Polarization• 1 polarization 

channel, {HH, VV}• stripmap, spotlight, ScanSAR

Dual Polarization• 2 polarization channels, 

{HH/VV, HH/HV, VV/HV}• stripmap, spotlight• coherent pol. phase• smaller elevation beam

H H H HTransmit

ReceiveV

H H H H

V V VH H H H

Quad Polarization• All 4 pol. channels• Stripmap• coherent pol. Phase• smaller elevation beam• Experimental product

H H H HTransmit

ReceiveV

V V V V

V V V

H H H HH H H H

V V V V

Twin Polarization• 2 polarization channels, 

{HH/VV, HH/HV, VV/HV}• stripmap• incoherent pol. phase• full elevation beam

H HTransmit

ReceiveV

H

V VHH

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Fully polarisation experimental mode specification:

System Parameters Values

HH/HV/VV/VH Scattering Matrix Local Incidence Angle 20-45 degreeSwath Width 15 km Slant Range Resolution 1.9 mGround Resolution 1 Look 7 m & 6 Look 15 mCross talk isolation 24 dB one wayNESZ better than -16 dB Radiometric calibration abs 1.10 dB, rel. 0.68 dB

TerraSAR-X: Fully Polarisation Mode

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Azimuth

Ran

ge

PI-SAR /Test Site: GIFU-Japan

X-band quad pol.

Courtesy: Hiroshi Kimura

Scattering Amplitude Images

HH

VV

HV

VH

⎥⎦

⎤⎢⎣

⎡

VVVH

HVHH

SSSS

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X-hh X-Band R:hh-vv G:2hv B:hh+vv

Single v. Fully PolarisedIncreasing Observation Space - Adding Information

PI-SAR / Test Site: GIFU- Japan Pauli-Scattering Vector

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Polarimetric Parameters / Scattering Matrix

• Scattering Amplitudes

•Total Power

• Amplitude Ratios

• Pol Phase Differences

• Helicity

⎥⎦

⎤⎢⎣

⎡−

−−=

||)(exp||)(exp||)(exp||)exp()exp(][

VVVVXXXX

VVXXXXVVHHHHVV

SiSiSiS

ririS

φφφφφφφκ

Five Parameters: 3 Amplitudes & 2 PhasesAbsolute PhaseFactor

⎥⎦

⎤⎢⎣

⎡=

VVXX

XXHH

SSSS

S][

NVVVVVVNXXXXXXNHHHHHH SSSSSS ||:||:||: *0*0*0 === σσσ

)/(// 0000000VVHHXXVVXXVVHH σσσσσσσ +

VVHHHHVV φφφ −=:

||||: RRLL SSHel −=

222 ||||4||: VVXXVV SSSTP ++=

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Polarimetric Parameters: Agricultural Fields

PI-SAR X-band / Test Site: Gifu, Japan

HH

Pauli RGB HH/VV Ratio

XX/HH Ratio XX/VV Ratio

Courtesy: Hiroshi Kimura

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Second Order Polarimetric Parameters

• Correlation Coefficients

• Scattering Entropy

• Scattering Anisotropy

• Polarimetric Alpha Angle

• Polarimetric Beta Angle

XX

VVHH

VVHH

SC

SSB

SSA

2:

)(21:

)(21:

=

−=

+=

⎥⎥⎥

⎦

⎤

⎢⎢⎢

⎣

⎡=

CBA

k3

r

VV

XX

HH

SC

SB

SA

=

=

=

:

2:

:

⎥⎥⎥⎥

⎦

⎤

⎢⎢⎢⎢

⎣

⎡

>=⋅=<∗∗

∗∗

∗∗

+

CCCBCABCBBBAACABAA

kkX 333 :][rr

Nine Parameters: 3 Real & 3 Complex Elements

>><<

><=

||||||:

**

*

VVVVHHHH

VVHHHHVV

SSSSSSγ

>><<

><=

||||||:

**

*

RRRRLLLL

RRLLLLRR

SSSSSSγ

32

32

32

32:PPPPA

+−

=+−

=λλλλ

321

:λλλ

λ++

= iiPi

ii PPH 3

3

1log: ∑

=

=

332211: αααα PPP ++=

332211: ββββ PPP ++=

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Polarimetric Parameters: Agricultural Fields

PI-SAR X-band / Test Site: Gifu, Japan

HH

Pauli RGB Entropy

Alpha Angle Anisotropy

Courtesy: Hiroshi Kimura

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Access to TerraSAR-X for scientific purposesTerraSAR-X mission goals:

provision of high resolution X-band data for scientific applicationsto develop a profitable and sustainable geo-information business based on TerraSAR-X data and products Equal share of the satellite’s capacity

Access for scientific purposes is gained via a selection processPre-launch AO (closed in October 2005)Further AO planned (End of 2007)General proposal submission interface (Summer 2007)

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The TerraSAR-X satellite has passed the Final Acceptance Review after successful

• Environmental testing. (Vibration, EMC, Thermal Balancing, Thermal Vacuum, Acoustic Noise, center of gravity)

• Integrated System Tests ( Functional, Performance, Characterization)

• Final antenna phase and amplitude trimming• Space segment to Ground segment Tests

(LEOP, mission sequence, end to end )

The satellite, the secondary payload (LCT and TOR) the ground segment (MOS, PGS, IOCS)are ready for launch! Shipment to Baikonouris planned for end January.

TerraSAR-X Mission Status