Phase gradient Autofocusing Technique (PGA)

Abstract

The phase-gradient autofocusing algorithm (PGA) has been widely used in spotlight Synthetic Aperture Radar (SAR) to compensate motion-induced blurs in the images. The PGA algorithm has proven to be a superior method for higher order autofocusing because it does not assume a model for the phase error. In this paper, a proposed pc-based software model of the PGA is introduced. Simulation results between blurred and focused images, or between the input phase error function and the estimated one carried out by calculating the rms value of the residual phase error, show significant removal of highorder phase errors and better removal of the low-order phase errors. Finally, a suggested graphical user interface (GUI) of the proposed algorithm for easier handling on pc-based equipments is introduced.