Signatures of surface targets with increasing speed in spotlight synthetic aperture radar

This paper investigates the signature characteristics in spotlight synthetic aperture radar (SAR) imagery for surface targets that are increasing speed during the collection interval. This study considers the broadside geometry case wherein the radar sensor moves with constant speed and heading on a level flight path. The analysis concentrates on the target migration effects in which the moving target smear exhibits some defocus in the range direction, although much smaller in magnitude than the smearing in the radar cross-range direction. This paper focuses on the case of a target that executes a speed transition during the SAR collection interval. The SAR simulations are shown to give moving target signatures that are in agreement with the predicted shapes of the central contours.