An efficient algorithm for fully capturing a ground moving target´s energy for spaceborne SAR-GMTI

A highly efficient algorithm is proposed to collect all the energy of a moving target, irrespective of its speed and direction, and has been applied to real RADARSAT-2 MODEX (Moving Object Detection Experiment) data. Results show that the algorithm maximizes the SCNR (signal-to-clutter-plus-noise ratio) in existing spaceborne SAR-GMTI (Synthetic Aperture Radar Ground Moving Target Indication) systems with a minimal increase in the processing load. Instead of attempting to match to all possible radial speeds of unknown movers in order to adequately apply SAR focusing, the algorithm requires only two full iterations of SAR processing per channel. The first iteration is a static world, full PRF (pulse repetition frequency) bandwidth SAR processing step. The second iteration is two DC (Doppler centroid) offset, half PRF bandwidth SAR processing iterations. By coherently combining the SAR-DPCA (displaced phase center antenna) images, the energy of movers can be completely recovered.