Simulations of Spotlight Synthetic Aperture Radar Super-resolution Algorithm

Aiming at the multi-angle spotlight SAR imaging mode, a multi-angle spotlight SAR super-resolution imaging algorithm is proposed. Multi-angle spotlight SAR uses a single-platform radar sensor for unidirectional observation of the same target in the azimuth direction, and it will obtain multi-angle information about the target. First, the imaging characteristics of multi-angle spotlight SAR are analyzed in the super-resolution imaging process. Second, the azimuth spectrum offset between echo signals at different angles is obtained. According to the spectrum offset, spectrum synthesis is conducted in the azimuth direction to complete multi-angle signal fusion. Next, the synthesized signal is tested and analyzed using chirp scaling imaging algorithm. Finally, the two-dimensional multiple signal classification spectrum estimation method is used for super-resolution imaging. Simulation experiments were conducted for single and multiple points. The short baseline imaging effect of the proposed algorithm is better than that of single-angle SAR imaging. The result in azimuth to 3 dB width is improved after super-resolution imaging. Multi-angle spotlight SAR can solve the serious defocusing problem of traditional imaging algorithms. Our experiments demonstrate that the imaging algorithm proposed in this paper is feasible.