2_prats_IGARSS2011_distributed_imaging_v4.ppt

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  • Auf dieser Folie sehen Sie ein Zusammenfassung der vielfältigen Potenziale bi- und multistatischer SAR Systeme.
  • 2_prats_IGARSS2011_distributed_imaging_v4.ppt

    1. 1. Pau Prats , Paco López-Dekker, Francesco De Zan, Steffen Wollstadt, Markus Bachmann, Ulrich Steinbrecher, Rolf Scheiber, Andreas Reigber, Gerhard Krieger Microwaves and Radar Institute (HR) German Aerospace Center [email_address] Distributed Imaging with TSX and TDX
    2. 2. Motivation <ul><li>Future SAR missions will exploit bi- and multistatic SAR systems. </li></ul><ul><li>Such systems increase the potential, reliability and flexibility of future SAR missions. </li></ul><ul><li>Potential: frequent monitoring, wide-swath imaging, single-pass interferometry, enhanced products (e.g. in terms of resolution). </li></ul><ul><li>Perform new experiments! ;c) </li></ul>G. Krieger and A. Moreira, “Spaceborne bi- and multistatic SAR: potential and challenges”, IEE Proc.-Radar Sonar Navig., vol. 153, no. 3, June 2006.
    3. 3. VU > Alberto Moreira <ul><li>SAR Interferometer </li></ul><ul><li>Close formation </li></ul><ul><li>Global DEM (HRTI-3) </li></ul>T erraSAR-X a dd o n for D igital E levation M easurements
    4. 4. TanDEM-X: Secondary Mission Objectives VU > Alberto Moreira Bistatic SAR Imaging Super Resolution Polarimetric SAR Interferometry Ground Moving Target Indication SAR Tomography Sea ice monitoring B 1 B 2 B 3     Crossed-orbits   Double Differential Interferometry Digital Beamforming
    5. 5. Some Experiments with Distributed Imaging <ul><li>Demonstration of distributed imaging with the following experiments: </li></ul><ul><ul><li>Range-resolution enhancement </li></ul></ul><ul><ul><li>Azimuth-resolution enhancement </li></ul></ul><ul><ul><li>Quad-pol synthesis with dual-pol acquisitions </li></ul></ul><ul><ul><li>Digital beamforming </li></ul></ul><ul><li>Elaborated manual commanding of each experiment </li></ul><ul><li>Experiments performed during the monostatic commissioning phase: </li></ul>20 km ~ 3 s TSX TDX Baseline needs to be compensated
    6. 6. TanDEM-X Commissioning Phase June‘10 July‘10 Aug‘10 Sep‘10 Oct‘10 Nov‘10 Dec‘10 Early Orbit Phase Grg Segment Checkout Bi-static Commissioning Phase 20 km Formation TDX Orbit Drift 16.000 km  20 km Close Helix-Formation 300-400 m Launch 21 June DEM Acquisition First SAR Image 24 June (MET +3.6) First DEM 16 July (MET +25) TDX Monostatic Comm. Phase 6 Months Commissioning Phase First close formation DEM 19 October (MET +124) First bi-static SAR image 8 August (MET +48) First single-pass bi-static DEM 2 October (MET +107)
    7. 7. Super Resolution in Range: Step-Frequency with TSX and TDX <ul><li>Limitation: RF filter allows maximum band of 300 MHz </li></ul><ul><li>Advantages within limitation: </li></ul><ul><ul><li>Increased SNR </li></ul></ul><ul><ul><li>Data rate distributed among satellites </li></ul></ul><ul><li>Baseline compensation for proper coherent combination </li></ul><ul><li>Negligible spectral shift for current configurations (but nevertheless considered) </li></ul>f 0 -  f f 0 +  f f 0 f r f r f r  TSX TDX 300 MHz
    8. 8. Super Resolution in Range: Step-Frequency with TSX and TDX Coregistration Common-band spectrum interferogram
    9. 9. Super Resolution in Range: Experimental Setup <ul><li>Data takes over Sydney, Australia, on August 15 and 26, 2010 </li></ul>
    10. 10. Super Resolution in Range: Experimental Results azimuth  range 
    11. 11. Super Resolution in Range: Experimental Results (II) Common-band interferogram azimuth  range 
    12. 12. Super Resolution in Range: Experimental Results (III) azimuth  range 
    13. 13. Super Resolution in Range: Experimental Results (IV) azimuth  range 
    14. 14. Super Resolution in Range: Experimental Results (V) azimuth  range 
    15. 15. Super Resolution in Range: Experimental Results (VI) Interferometric coherence between synthesized images Interferometric phase between synthesized images azimuth  range 
    16. 16. Super Resolution in Azimuth f DC,1 f DC,2 f DC,mean f a f a f a  TSX TDX
    17. 17. Super Resolution in Azimuth: Experimental Setup <ul><li>Data take over Neustrelitz, Germany, on September 20, 2010 </li></ul>
    18. 18. Super Resolution in Azimuth: DTAR Analysis TDX DTAR: -21.67 dB TSX DTAR: -21.04 dB Maximum bandwidth DTAR: -19.91 dB Twice the resolution DTAR: -21.42 dB
    19. 19. Super Resolution in Azimuth: Experimental Results (I) azimuth  range 
    20. 20. Super Resolution in Azimuth: Experimental Results (II) Common-band interferogram azimuth  range 
    21. 21. Super Resolution in Azimuth: Experimental Results (III) azimuth  range 
    22. 22. Super Resolution in Azimuth: Experimental Results (IV) azimuth  range 
    23. 23. Super Resolution in Azimuth: Experimental Results (V) azimuth  range  azimuth  range 
    24. 24. Super Resolution in Azimuth: Experimental Results (VI) <ul><li>Measured resolutions over a corner reflector: </li></ul><ul><li>TSX: 2.97m </li></ul><ul><li>TDX: 2.97 m </li></ul><ul><li>Combined: 1.49 m </li></ul>
    25. 25. Quad-Pol Synthesis with Dual-Pol Acquisitions <ul><li>Each satellite acquires a co-pol and a cross-pol channel, e.g. HH-VH and HV-VV </li></ul><ul><li>The cross-pol channel is used to estimate the calibration phase </li></ul><ul><li>Better SNR and DTAR when compared to the experimental quad-pol product using the dual receive antenna (DRA) mode </li></ul><ul><li>DLR’s E-SAR example: quad-pol synthesis at C-band with repeat-pass dual-pol acquisitions [1] </li></ul>E-SAR [1] R. Scheiber et al. , “Radar data processing, quality analysis and level-1b product generation for AGRISAR and EAGLE campaigns,” in AGRISAR and EAGLE Campaigns Final Workshop, Noordwijk, The Netherlands, Oct. 15-16 2007.
    26. 26. Quad-Pol Synthesis: Experimental Results <ul><li>New acquisitions performed in bistatic mode are on their way. </li></ul>azimuth  range 
    27. 27. Conclusion & Future Work <ul><li>Proof of concept of several experiments with TSX and TDX </li></ul><ul><ul><li>Range-resolution enhancement </li></ul></ul><ul><ul><li>Azimuth-resolution enhancement </li></ul></ul><ul><ul><li>Quad-pol synthesis with dual-pol acquisitions </li></ul></ul><ul><li>Qual-pol synthesis with dual-pol acquisitions using bistatic data (close formation) </li></ul><ul><li>Further performance analyses, especially for the azimuth case </li></ul><ul><li>By doubling the PRF one can obtain simultaneously a resolution improvement in both dimensions </li></ul><ul><li>Digital beamforming with an interferometric baseline </li></ul>
    28. 28. Thank you for your attention! VU > Alberto Moreira

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