An improved topography and aperture dependent motion compensation algorithm

Airborne SAR focusing is affected by motion errors corrupting data acquired onboard. In order to account for these errors, MOtion COmpensation (MOCO) algorithms are necessary. However, efficient implementation of such MOCO algorithms requires use of proper approximations in the sensor-to-target distance history, which may impair the accuracy of the final SAR images. To circumvent this problem, some methods, such as the PTA (which stands for Precise Topography- and Aperture- dependent) algorithm, have been recently devised in the literature. This paper discusses limits of the PTA algorithm and provides some modifications aimed at improving its performances.