PGA, Phase Gradient Autofocus Algorithm

The Phase Gradient Autofocus (PGA) algorithm is highly valuable for motion compensation in Synthetic Aperture Radar (SAR) systems. This algorithm can be implemented through four sequential steps. First, radar data undergoes preprocessing including clutter removal and system error correction, typically implemented using filtering techniques and calibration routines. Second, the phase gradient algorithm performs autofocus processing on radar data through phase error estimation and correction, often utilizing Fourier transforms and gradient calculations to achieve high-resolution imagery. Third, motion compensation algorithms correct radar data by applying phase adjustments to eliminate blurring caused by target movement, frequently implemented using motion parameter estimation and phase compensation functions. Finally, postprocessing techniques including noise reduction and image enhancement are applied to the corrected data, employing filters and contrast adjustment methods to produce clear SAR images. This algorithm holds significant application value in synthetic aperture radar imaging by improving image quality through robust phase error correction.