Modified Polar Format Algorithm for High-Resolution Wide-Swath DBF SAR

The digital beam forming (DBF) synthetic aperture radar (SAR) system can operate with a pulse repetition frequency (PRF) dramatically lower than the Doppler bandwidth, thus can provide high-resolution and wide-swath (HRWS) SAR images. In traditional DBF SAR, a preprocessing to reconstruct the umambiguous signal spectrum is required before image formation processing. In this paper, the signal model for DBF SAR is presented and analyzed from the Fourier transform viewpoint. Then based on the multichannel Fourier model, a modified polar format algorithm is proposed to process the DBF SAR data. The new algorithm don't need any preprocessing operations, therefore possesses higher computational efficiency.