WE3.L10.3: THE FUTURE OF SPACEBORNE SYNTHETIC APERTURE RADAR

The Future of Spaceborne Synthetic Aperture Radar

G. Krieger, A. Moreira

Microwaves and Radar InstituteGerman Aerospace Center (DLR)

A Tribute to the Pioneer Work of Kiyo Tomiyasu

The Future of Spaceborne Synthetic Aperture RadarIGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu

First Civilian SAR Satellite: Seasat

2300 kgWeight

25 m x 25 mResolution100 kmSwath Width

10,74 m x 2,16 m

AntennaSize~ 23°Incident Angle

19 MHz Bandwidth~780 kmAltitude

0,235 mWavelengthJune 26, 1978Launch


SAR Missions since 1978 (selection)

SEASATNASA/JPL (USA)

L-Band, 1978

ERS-1/2European Space Agency (ESA)

C-Band, 1991-2000 & 1995-today

SIR-C/X-SARNASA/JPL, L- and C-Band (quad)

DLR / ASI, X-bandApril and October 1994

J-ERS-1Japanese Space Agency (NASDA)

L-Band, 1992-1998

RADARSAT-1Canadian Space Agency (CSA)

C-Band, 1995-today

SRTMNASA/JPL (C-Band), DLR (X-Band)

February 2000

ENVISAT / ASAREuropean Space Agency (ESA)

C-Band (dual), 2002-today

ALOS / PALSARJapanese Space Agency (JAXA)

L-Band (quad), 2005

TerraSAR-XGerman Aerospace Center (DLR) / Astrium

X-Band (quad), 2007

RADARSAT-2Canadian Space Agency (CSA)

C-Band (quad), 2007

SAR LupeBWB GermanyX-Band, 2006

CosmoSkymedASI / Alenia

X-Band (dual), 2007


EarthquakesEarthquakes VolcanoesVolcanoes

OceanOcean

Land & Sea IceLand & Sea Ice

SubsidenceSubsidence

TrafficTraffic

Land EnvironmentLand Environment

ReconnaissanceReconnaissanceDisaster Disaster


Application Areas for SAR Data Future RequirementsEarthquakesEarthquakes VolcanoesVolcanoes

OceanOcean



TrafficTraffic



EarthquakesEarthquakes VolcanoesVolcanoes

OceanOcean



TrafficTraffic



Future SAR Systems: Motivation

•wider coverage andshorter revisit times

•higher geometric and radiometric resolution

•new data products from coherent combinations of SAR images:- Delta-DEMs(ice mass balance, ...)

- 3-D volume imaging(forest structure, ...)

- 4-D tomography (biomass dynamics, …)

• reliable data supply•cost efficiency


•wider coverage andshorter revisit times

•higher geometric and radiometric resolution

•new data products from coherent combinations of SAR images:- Delta-DEMs(ice mass balance, ...)

- 3-D volume imaging(forest structure, ...)

- 4-D tomography (biomass dynamics, …)

• reliable data supply•cost efficiency

Future SAR Systems: Motivation

The Many Ingenious Ideas of Kiyo Tomiyasu Future Requirements


(IEEE EASCON, 1978)


TanDEM-X


TanDEM-X Launch, June 21, 2010


First TanDEM-X Interferogram & DEM(Large Baseline Pursuit Monostatic)

October Revolution

Island



20 km

38 km



hamb = 3 m Beff = 2.6 kmx = 20 m x 20 mh 10 cm



• TanDEM-X Special Session: Thursday, 8:20 – 10:00 am

• Prats et al., “Taxi: A versatile processing ...,” Friday, 9:40 – 10:45 am

• www.dlr.de

hamb = 3 m Beff = 2.6 kmx = 20 m x 20 mh 10 cm


“Double Differential SAR Interferometry”

Grounding line detection, vegetation growth, snow/ice accumulation, … ?

h(t1)

h ~ 2 - 1

coherence between passes not mandatory

1pass 1

pass 2

h < 10 cm h(t2)

2

Bistatic Strip mapB = 3000 m x = 12 m

Bistatic Strip mapB = 3000 m x = 12 m

e.g. difference between two single-pass cross-track interferograms

Measurement of Height Changes

Vorhaben TanDEM-X Nutzung

Single-Pass InSAR for Ice Monitoring

High uncertainty about future sea level rise High uncertainty about future sea level rise IPCCIPCC’’07 height increase 28 07 height increase 28 -- 43 cm, now 1.4 m43 cm, now 1.4 mmajor uncertainty: stability of polar ice sheetsmajor uncertainty: stability of polar ice sheets

Large Baseline SingleLarge Baseline Single--Pass Pass InSARInSARprovides high resolution also in complex terrainprovides high resolution also in complex terrainavoids gaps of laser & radar altimetry systems avoids gaps of laser & radar altimetry systems allows accurate observation of temporal evolutionallows accurate observation of temporal evolution

Vorhaben TanDEM-X Nutzung

Single-Pass InSAR for Ice Monitoring

High uncertainty about future sea level rise High uncertainty about future sea level rise IPCCIPCC’’07 height increase 28 07 height increase 28 -- 43 cm, now 1.4 m43 cm, now 1.4 mmajor uncertainty: stability of polar ice sheetsmajor uncertainty: stability of polar ice sheets

Large Baseline SingleLarge Baseline Single--Pass Pass InSARInSARprovides high resolution also in complex terrainprovides high resolution also in complex terrainavoids gaps of laser & radar altimetry systems avoids gaps of laser & radar altimetry systems allows accurate observation of temporal evolutionallows accurate observation of temporal evolution

• Börner et al., “SIGNAL: SAR for Ice, Glacier ...” Thursday, 9:40 – 10:45 am


~ 30 m

Estimation of the vertical structure of volume scatterers:

Vertical structure components are resolved by meansof their polarimetric signature;

The (height) location of the resolved structuralcomponents is estimated by interferometric measurements.

Measurement of Vegetation Height

PolarimetricPolarimetric SAR SAR InterferometryInterferometry

((PolPol--InSARInSAR))



Combination of Multiple Single-Pass Interferograms

Measurement of 3-D Vegetation Structure

pass 1 pass k pass N

* * *

Reconstruction of Scattering Profile(van Cittert-Zernike theorem)

… …



Tomography: A Revolution in Medical Diagnostics and Research


The Next Revolution: Functional Brain ImagingThe Next Revolution: Functional Brain Imaging


The Next Revolution: Functional Brain ImagingThe Next Revolution: Functional Brain Imaging

44--D SAR ImagingD SAR Imagingmonitoring internal structure changes


44--D SAR ImagingD SAR Imagingmonitoring internal structure changes

in forests, ice, snow, permafrost soils, ...


fP1

fP2

fP3

ambiguities

ambiguities suppressed

Use of Compact Antennas

v

TxRx 2 Rx 1Rx 3


),( txs2),( txs1

),( txs3),( txsN

Challenge:Optimum Combination

N

iii dtdxtxstxtxh

1

'')','()',',,(

),( txs1 ),( txsN

Interf.Comb.

SARProc.

SARProc.

x

SARProc.

SARProc.

x

SARProc.

SARProc.

x

SARProc.

SARProc.

x

SARProc.

SARProc.

x

),( txsi ),( txs j

Nonlinear Approach),( txs1 ),( txsN

),(),...,,( txstxsf N1

Linear Beamforming:• ambiguity

suppression• wide swath

imaging• tomography • MTI (e.g. STAP)• super-resolution• interference

suppression

Interferometry: • cross-track (DEM,

Pol-InSAR)• coherence

tomography • along-track (ocean

currents, MTI)

Multistatic Sparse Array


Sparse Apertures and Reconfigurable Arrays


FrequentFrequentMonitoringMonitoring


GEO+LEOGEO+LEOGEOGEO

Kiyo Tomiyasu

(IEEE Ant. & Prop. Symp., 1978) (IEEE EASCON, 1978)


GEO-LEO SAR: NESZ Example

200 km 200 km 200 kmBr<300MHz

res< 6m

nadir-lookingSAR enables synergy with

other instruments(e.g. optical sensors,

altimeters, ....)

Wavelength 3.1 cm Max. Bandwidth 300 MHz Average Transmit Power 1000 W Antenna Size Tx 100 m2 Antenna Size Rx 6 m2

Noise Figure + Losses 5 dB Receiver Altitude 400 km Ground Resolution 3 m Max. Res. Cell Diameter 6 m


LEOreceiver

satellite

transmitter

Transmitter Footprint125 km x 250 km(X-Band, dant=10m, =48°)

Receiver Footprint 10 km

(X-Band, dant=2m, inc<40°)

Antenna Footprint Comparison


RxTx

Multiple Beams on Receive


AD

AD

AD

AD

AD

SAR Processing

x x x x x

Multiple beamswith adaptableantenna patterns

Mixing

AnalogDigitalConversion

DigitalSignal Processing

Focusing andHigher-Level Processing

Digital Beam Forming

Receiver

Transmitter

Digital Beamforming on Receive


Usage of Tx Power

Global Monitoring

High-Resolution Wide-Swath Imaging

gain improved by more than 10 dB

19.12.2005 Vortragstitel 38

Echolocationin Bats


PinnaPinna Movement for Angular "Scan on Receive" Movement for Angular "Scan on Receive"

DBFDBF--SAR SAR withwith ReflectorReflector AntennasAntennas


3 revisits / day (for 1 satellite)

huge simultaneous access area

system concept based on advanced DBF architecture

MEOSARMEOSAR

multi-frequencycapability


Adaptive & Cognitive MIMO SAR SystemsAdaptive & Cognitive MIMO SAR Systems

HRWS HRWS StripmapStripmap

Spotlight Spotlight ZoomZoom

Wide Area Wide Area SearchSearch

maximize information gain for a given power & data budget

optimized distribution of system resources environmentenvironment

DBF on DBF on receivereceive

waveformwaveformencodingencoding

salient features

beam trigger


Kiyo Tomiyasu

Best wishes and many congratulations!

WE3.L10.3: THE FUTURE OF SPACEBORNE SYNTHETIC APERTURE RADAR

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Transcript of WE3.L10.3: THE FUTURE OF SPACEBORNE SYNTHETIC APERTURE RADAR