The document discusses the history and future of spaceborne synthetic aperture radar (SAR). It summarizes key details of early SAR satellites like Seasat and missions since 1978. The text outlines future requirements like wider coverage, higher resolution, and new data products. It proposes concepts like bistatic SAR, polarimetric SAR interferometry, and 4D SAR tomography to measure changes in vegetation, ice, and other surfaces over time. Finally, it discusses ideas proposed by Kiyo Tomiyasu for compact antennas and GEO-LEO SAR configurations to enable more frequent global monitoring with high resolution.
1. A Tribute to the Pioneer Work of Kiyo Tomiyasu
The Future of Spaceborne Synthetic Aperture Radar
G. Krieger, A. Moreira
Microwaves and Radar Institute
German Aerospace Center (DLR)
2. First Civilian SAR Satellite: Seasat
Launch June 26, 1978 Wavelength 0,235 m
Altitude ~780 km Bandwidth 19 MHz
Weight 2300 kg Antenna 10,74 m x
Size 2,16 m
Incident Angle ~ 23°
Swath Width 100 km Resolution 25 m x 25 m
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
3. First Civilian SAR Satellite: Seasat
Launch June 26, 1978 Wavelength 0,235 m
Altitude ~780 km Bandwidth 19 MHz
Weight 2300 kg Antenna 10,74 m x
Size 2,16 m
Incident Angle ~ 23°
Swath Width 100 km Resolution 25 m x 25 m
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
4. SAR Missions since 1978 (selection)
SEASAT ERS-1/2 J-ERS-1 SIR-C/X-SAR
NASA/JPL (USA) European Space Agency (ESA) Japanese Space Agency (NASDA) NASA/JPL, L- and C-Band (quad)
L-Band, 1978 C-Band, L-Band, 1992-1998 DLR / ASI, X-band
1991-2000 & 1995-today April and October 1994
RADARSAT-1 SRTM ENVISAT / ASAR ALOS / PALSAR
Canadian Space Agency (CSA) NASA/JPL (C-Band), DLR (X-Band) European Space Agency (ESA) Japanese Space Agency (JAXA)
C-Band, 1995-today February 2000 C-Band (dual), 2002-today L-Band (quad), 2005
SAR Lupe CosmoSkymed TerraSAR-X RADARSAT-2
BWB Germany ASI / Alenia German Aerospace Center (DLR) / Astrium Canadian Space Agency (CSA)
X-Band, 2006 X-Band (dual), 2007 X-Band (quad), 2007 C-Band (quad), 2007
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
5. Earthquakes Volcanoes Land & Sea Ice
Ocean Land Environment Subsidence
Traffic Disaster Reconnaissance
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
6. Future SAR Systems: Motivation
Application Areas for SAR Data Future Requirements
Earthquakes Volcanoes Land & Sea Ice • wider coverage and
shorter revisit times
• higher geometric and
radiometric resolution
• new data products from
Ocean Land Environment Subsidence coherent combinations
of SAR images:
- Delta-DEMs
(ice mass balance, ...)
- 3-D volume imaging
Traffic Disaster Reconnaissance (forest structure, ...)
- 4-D tomography
(biomass dynamics, …)
• reliable data supply
• cost efficiency
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
7. Future SAR Systems: Motivation
The Many Ingenious Ideas of Kiyo Tomiyasu Future Requirements
• wider coverage and
shorter 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
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
8. (IEEE EASCON, 1978)
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
9. TanDEM-X
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
10. TanDEM-X Launch, June 21, 2010
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
11. The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
12. First TanDEM-X Interferogram & DEM
(Large Baseline Pursuit Monostatic)
October
Revolution
Island
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
13. First TanDEM-X Interferogram & DEM
(Large Baseline Pursuit Monostatic)
20 km
38 km of Spaceborne Synthetic Aperture Radar
The Future
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
14. First TanDEM-X Interferogram & DEM
(Large Baseline Pursuit Monostatic)
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
15. First TanDEM-X Interferogram & DEM
(Large Baseline Pursuit Monostatic)
hamb = 3 m
Beff = 2.6 km
x = 20 m x 20 m
h 10 cm
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
16. First TanDEM-X Interferogram & DEM
(Large Baseline Pursuit Monostatic)
hamb = 3 m
Beff = 2.6 km
x = 20 m x 20 m
h 10 cm
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
17. First TanDEM-X Interferogram & DEM
(Large Baseline Pursuit Monostatic)
hamb = 3 m
Beff = 2.6 km
x = 20 m x 20 m
h 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
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
18. Measurement of Height Changes
“Double Differential SAR Interferometry”
e.g. difference between two single-pass cross-track interferograms
pass 1
Bistatic 1
Bistatic
Strip map
Strip map
B ==3000 m
B 3000 m
x ==12 m h(t1)
x 12 m
pass 2
2
h < 10 cm
h(t2)
h ~ 2 - 1
coherence between
passes not mandatory
Grounding line detection, vegetation growth, snow/ice accumulation, … ?
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
19. Single-Pass InSAR for Ice Monitoring
High uncertainty about future sea level rise
IPCC’07 height increase 28 - 43 cm, now 1.4 m
major uncertainty: stability of polar ice sheets
Large Baseline Single-Pass InSAR
provides high resolution also in complex terrain
avoids gaps of laser & radar altimetry systems
allows accurate observation of temporal evolution
Vorhaben TanDEM-X Nutzung
20. Single-Pass InSAR for Ice Monitoring
• Börner et al., “SIGNAL: SAR for Ice, Glacier ...”
Thursday, 9:40 – 10:45 am
High uncertainty about future sea level rise
IPCC’07 height increase 28 - 43 cm, now 1.4 m
major uncertainty: stability of polar ice sheets
Large Baseline Single-Pass InSAR
provides high resolution also in complex terrain
avoids gaps of laser & radar altimetry systems
allows accurate observation of temporal evolution
Vorhaben TanDEM-X Nutzung
21. Measurement of Polarimetric SAR
Vegetation Height Interferometry
(Pol-InSAR)
m
30
~
Estimation of the vertical structure of volume scatterers:
Vertical structure components are resolved by means
of their polarimetric signature;
The (height) location of the resolved structural
components is estimated by interferometric measurements.
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
22. Measurement of 3-D
Vegetation Structure
Combination of Multiple
Single-Pass Interferograms
pass 1 pass k pass N
… …
* * *
Reconstruction of Scattering Profile
(van Cittert-Zernike theorem)
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
23. The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
24. Tomography: A Revolution in Medical Diagnostics and Research
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
25. The Next Revolution: Functional Brain Imaging
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
26. The Next Revolution: Functional Brain Imaging
4-D SAR Imaging
monitoring internal
structure changes
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
27. 4-D SAR Imaging
monitoring internal
structure changes
in
forests, ice, snow,
permafrost soils, ...
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
28. Use of Compact Antennas
ambiguities Rx 3 Rx 2 Rx 1 Tx
v
P1 f
P2 f
ambiguities
suppressed
P3 f
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
29. Multistatic Sparse Array
Linear Beamforming: s3(x,t ) Interferometry:
s2(x,t ) sN (x,t )
• ambiguity s1(x,t ) • cross-track (DEM,
suppression Pol-InSAR)
• wide swath • coherence
imaging tomography
• tomography • along-track (ocean
• MTI (e.g. STAP) currents, MTI)
• super-resolution si ( x,t ) s j ( x,t )
• interference
suppression SAR SAR
SAR
SAR SAR
SAR
s1( x,t ) sN (x,t ) SAR
SAR Proc. SAR
SAR Proc.
Challenge: Proc.
Proc. Proc.
Proc.
Proc.
Proc. Proc.
Proc.
Optimum Combination
N xx
x
h (x,t, x',t' ) s (x',t' ) dx'dt'
Nonlinear Approach x
i i s1( x,t ) sN ( x,t ) x
i 1
f s1( x,t ),..., sN ( x,t )
Interf.
Comb.
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
30. Sparse Apertures and Reconfigurable Arrays
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
31. Frequent
Monitoring
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
32. Kiyo
Tomiyasu
(IEEE Ant. & Prop. Symp., 1978) (IEEE EASCON, 1978)
GEO+LEO
GEO
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
33. GEO-LEO SAR: NESZ Example
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 3m
Max. Res. Cell Diameter 6m
nadir-looking
SAR enables
synergy with
other instruments
(e.g. optical sensors,
altimeters, ....)
res< 6m
200 km 200 km 200 km
Br<300MHz
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
34. Antenna Footprint Comparison
LEO
er
receiv
te
satelli
Receiver Footprint
10 km
(X-Band, dant=2m, inc<40°)
Transmitter Footprint
125 km x 250 km
(X-Band, dant=10m, =48°)
transmitter
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
35. Multiple Beams on Receive
Tx Rx
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
36. Digital Beamforming on Receive
Transmitter
Multiple
Receiver beams
with adaptable
antenna
patterns
Mixing x x x x x
Analog A A A A A
Digital D D D D D
Conversion
Digital
Signal Digital Beam Forming
Processing
Focusing and
Higher-Level SAR Processing
Processing
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
37. Global Monitoring
High-Resolution Wide-Swath Imaging
Usage of Tx Power
gain improved by
more than 10 dB
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
38. Echolocation
in Bats
19.12.2005 Vortragstitel 38
46. MEOSAR
3 revisits / day
(for 1 satellite)
huge
simultaneous
access area
multi-
frequency
capability
system concept based on
advanced DBF architecture
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
47. Adaptive & Cognitive MIMO SAR Systems
maximize information gain for salient features
a given power & data budget
beam trigger
DBF on waveform
receive encoding
Spotlight
Zoom
Wide Area HRWS
Search Stripmap
environment
optimized distribution of system resources of Spaceborne Synthetic Aperture Radar
The Future
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
48. The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu
49. Kiyo Tomiyasu
Best wishes and many congratulations!
The Future of Spaceborne Synthetic Aperture Radar
IGARSS 2010 - Special Session Honoring the Achievements of Kiyo Tomiyasu