Range cell migration in the spotlight SAR polar format algorithm

Compensation of scatterer range cell migration is an important aspect of accurate spotlight SAR image formation. The polar format algorithm (PFA) is a method for processing fine resolution SAR radar data which utilizes a polar arrangement of the echo spectra in the backscatter frequency domain. It is shown that the PFA resampling from a polar to rectangular grid generates a linear phase function on the resampled data that after the Fourier transform to the image domain, fully compensates the linear component of the range cell migration. This new perspective of the PFA range cell migration correction is derived using signal phase history and tomographic approaches