Preliminary design of a SAR-GMTI processing system for RADARSAT-2 MODEX data

The RADARSAT-2 satellite includes an experimental mode, called the moving object detection experiment (MODEX), which is to be used to perform ground moving target indication (GMTI) using a C-band synthetic aperture radar (SAR). During MODEX operation, the SAR antenna is partitioned into two subapertures along the satellite track to sequentially observe the same scene from the same spatial point. By appropriate processing of the returned signals from each channel, detection of temporal changes in the scene (i.e. moving targets) can be accomplished. The MODEX configuration will be used by the Canadian Department of National Defense RADARSAT-2 GMTI demonstration project, which aims to develop a SAR-GMTI processing system to investigate the military and commercial utility of space-based moving target measurements. This paper discusses a conceptual SAR-GMTI processor design in terms of selected algorithms and their performance, such as along track interferometry (ATI), displaced phase center antenna (DPCA) and iterative moving target (terrain) matched filtering (MTMF). Processing issues arising in space based radar (SBR) GMTI are also discussed. It is anticipated that the ultimate processor design will incorporate these algorithms as independent processing configurations, along with selection rules that will optimize their use to the contents of the image scene.