The Polar Format Imaging Algorithm Based on Double Chirp-Z Transforms

摘要

Spotlight mode offers finer azimuth resolution than that achievable in stripmap mode using the same physical antenna. The most popular spotlight synthetic aperture radar (SAR) reconstruction method is the classic polar format algorithm (PFA). However, PFA needs to perform range and azimuth interpolation operations during SAR imaging, which, in turn, affect the imaging precision and the computation efficiency. In this letter, we present a novel polar format algorithm, which may avoid interpolation operations by double chirp-Z transform. In this letter, we also analyze the nondefocus and the nondistortion constraints and discuss the along-track acceleration constraint for the PFA as well.