Modified polar format algorithm (MPFA) for highly-squinted SAR

In the high-resolution highly-squinted (HRHS) synthetic aperture radar (SAR) processing, the residual errors of conventional polar format algorithm (PFA) brought by far-field assumption greatly deteriorate the reconstruction performance, which limits the allowable scene size. To address this problem, a modified PFA for HRHS SAR is presented with a new two-dimensional (2-D) interpolation function in this Letter. Different from the conventional PFA, the modified one has a larger focus depth and is insensitive to the target height. Simulation results verify the effectiveness of the modified PFA.