STUDY AND DEVELOPMENT OF A SAR AZIMUTH-COMPRESSION AUTOFOCUSSING PROCESSOR BASED ON THE OMEGA-K SEISMIC MIGRATION TECHNIQUE

The azimuth compression of SAR images by the omega-kappa seismic migra tion technique involves the retro-propagation of range-compressed data to their proper backscattering positions to reconstruct the reflectiv ity map of the observed surface. We critically review the basic assump tions of the omega-kappa seismic migration algorithm, which is a first -order approximation to the exact tomographic formulation of SAR recon struction. We then describe azimuth-compression software implemented o n a work station in the SAR Image Laboratory within ESTEC's On-Board D ata Handling Division. The focussing sensitivity to critical parameter s and phase fidelity of the omega-kappa algorithm are analysed. Perspe ctives for implementation on-board spacecraft are also discussed.