Azimuth Ambiguity Suppression for Azimuth Multichannel SAR Based on Subband Rearrangement

Azimuth multichannel synthetic aperture radar (SAR) is one of the key techniques for achieving high-resolution wide-swath (HRWS) observation. The non-bandlimited nature of the azimuth signal results in residual aliasing spectra after multichannel spectrum recovery, leading to azimuth ambiguity. In this paper, we first analyze the causes of multichannel SAR azimuth ambiguity after spectrum recovery, and then propose an azimuth ambiguity suppression method. The core of this method is the use of subband rearrangement (SR), which enhances the energy of azimuth ambiguity in the image domain, thereby facilitating its location and suppression. Experiments conducted using both simulated data and GaoFen-3 real data compare the proposed method with three existing methods, demonstrating the effectiveness of the proposed method.