Utilising signal absence in SAR imagery for moving target detection

SAR images of moving targets are blurred, defocused and displaced from their true location making them difficult to detect from their direct energy returns. This paper presents an alternate technique for detecting such targets by exploiting the phenomenon that the shadow projected by the target produce a null in the SAR imagery. The target shadow is presented at its true location and tracks the target as it moves along in the scene. A change detection technique has been developed that processes a sequence of highly overlapped SAR images. Initial detections thus obtained then seed a shadow delineation process that simultaneously delineates the shadows of the moving targets over multiple images. The technique has been successfully demonstrated on real SAR imagery for detecting and locating moving targets