Performances analysis of moving target tracking in circular SAR

Ground moving target focusing and tracking using airborne data is a subject of increasing interest. Single antenna processing allows focusing [1] and azimuthal velocity estimation [2][3] under the assumption that the signal-to-clutter ratio (SCR) is high enough (for instance, 14dB in [3]), which is mostly not the case in an urban context. Moreover, these methods are insufficient to geolocalize the moving targets. Acquisition of SAR data over a circular path eliminates this drawback, because objects may be seen at a 360° angle during a longer time than in the case of linear path. A technique to track moving targets in SAR images with only one sensor and using a circular path has been presented in [4]. In this paper, we perform a physical and geometrical analysis of this method and present accuracy evaluations. Finally some new results are presented on real data acquired around the city of Nîmes (X band).