ADAPTIVE SIDELOBE SUPPRESSION OF SAR IMAGES WITH ARBITRARY DOPPLER CENTROIDS AND BANDWIDTHS

Sidelobe suppression is an issue of interest in SAR imaging. In order to obtain low-sidelobe SAR images, various sidelobe suppression methods have been proposed. SVA (Spatially Variant Apodization) method can both maintain image resolution and suppress sidelobes. However, this method assumes that the Doppler centroid is zero and the Doppler bandwidth is close to the pulse repetition frequency (PRF). Actually, when the radar has a radial velocity, the Doppler centroid may deviate from zero and the Doppler bandwidth may be significantly smaller than the PRF. In such case, the method has poor performance in suppressing sidelobes. This new algorithm proposed in this paper not only inherits the advantage that the SVA maintains image resolution, but also considers arbitrary Doppler centroids and bandwidths. The result of simulated and real SAR images indicates the advantage of this new algorithm over the traditional methods.