A NOVEL SAR IMAGING PROCESSING METHOD BASED ON FRACTIONAL FOURIER TRANSFORM

摘要

The fractional Fourier transform (FRFT) is a potent tool to analyze the chirp signal. Here a novel SAR imaging technique based on FRFT is studied. We apply FRFT to range compressed data instead of executing RCMC and Azimuth compression. By FRFT, we estimate 1) Doppler rate, 2) amplitude 3) azimuth beam center crossing time which means azimuth location of a point target in image in accurate way. The relative range locations of point targets can be also determined by the formulation of Doppler rate. Then SAR image can be reconstructed together with estimated amplitudes. The relationship between FRFT order and SAR resolution is also studied. Furthermore, we simulate this method from a multi-points view.