A modefied PGA motion compensation method for circular trace scanning SAR

A modified phase gradient autofocus (PGA) method tailored for circular trace scanning synthetic aperture radar (CTSSAR) is provided in this paper to handle the motion compensation problem. In CTSSAR, the circular orbit makes the imaging and the motion compensation hard to perform, and the traditional algorithms cannot accomplish precise imaging. Different from the classical PGA method, the modified PGA algorithm takes the residual high order phase errors into account. The precise phase estimation can be achieved after the residual phase errors are accurately estimated and compensated. Simulation results are presented to demonstrate the validity of the proposed approach.