Poly Beam Synthetic Aperture Radar Imaging Processing

Spotlight Synthetic Aperture Radar(SAR) is a kind of high resolution imaging radar, and overcomes the azimuth resolution restriction of the stripmap mode SAR. So it provides the better azimuth resolution, and collects SAR imaging data in the larger angle of view. The paper discusses the doppler history and time-frequency region relation of spotlight SAR echo in theory, analyzes the key deramp technology and the compensation of residual video phase in detail. In chapter 4, it discusses two imaging algorithms, SPECAN-RD algorithm and Frequency Scaling algorithm, then carries out point target simulation and compares their performance. From the simulation and the real imaging result, it concludes that Frequency Scaling algorithm is better than SPECAN-RD algorithm. But SPECAN-RD algorithm is more suited to the real-time imaging processing because of its less calculation. In addition, this paper discusses a robust autofocus algorithm: Phase Gradient Algorithm, which is suited to spotlight SAR, and applies it in stripmap mode SAR, obtains the satisfied imaging result. In a word, the paper analyzes the two imaging algorithm of airborne spotlight mode SAR in detail, validates them and compares their performances by point target simulation and imaging processing of the real data. And, it applies PGA algorithm in stripmap SAR imaging processing successfully.