Spatially variant interference suppression method based on superresolution algorithm for synthetic aperture radar

Synthetic Aperture Radar (SAR) often suffers from interference signal from various radio sources. In general, notch filters or band elimination filters have been utilized to eliminate such interference signal; however, if the bandwidth of the interference signal is relatively wide, the gap in the spectrum caused by the band elimination filter could significantly degrade the original image. We propose an algorithm to suppress relatively wide bandwidth interference while maintaining the image quality. In the algorithm, spatially variant interference suppression filter is generated based on the signal of interference free band, then the filter is applied to the interference contaminated image. Unlike the band elimination filter, the spatially variant interference suppression filter preserves the signal component within the interference contaminated band; therefore, the image distortion caused by the spectrum gap can be largely eliminated. The algorithm has been tested with a simulated interference contaminated image generated from the real 10cm resolution airborne Ku band SAR image and a TerraSAR-X image. It has been shown that while conventional band elimination filter would degrade the image quality, the image quality of the interference suppressed image obtained by the proposed algorithm is satisfactory.