Spatially Varying Sidelobe Suppression for Spaceborne SAR Terrain Matching Curved Imaging

The terrain matching curved (TMC) imaging is a promising technique to observe the long curved terrain efficiently. By adjusting the beam in azimuth and range simultaneously, a curved swath matching with the long curved terrain can be generated, achieving high efficient data acquisition. However, due to the complex beam steering in the TMC imaging, the Doppler bandwidth and the sidelobe direction of the image are spatially varied among the long curved terrain, resulting in a failure of sidelobe suppression using the sidelobe suppression traditional method. To solve this problem, a new spatially varying sidelobe suppression method is proposed in this paper. By calculating the Doppler history of targets during the beam illumination, a spatially variable window adapting to the Doppler bandwidth variation can be designed accurately, achieving sidelobe suppression in the TMC imaging effectively. The validity of the proposed algorithm is verified by simulation.