An accurate focusing method in GEO SAR

In Geosynchronous Synthetic Aperture Radar (GEO SAR), synthetic aperture time is very long, which makes the classical line trajectory model and Fresnel approximation invalid. The paper firstly analyses the coverage in GEO SAR, and then analyses the error caused by the line trajectory model and Fresnel approximation. Next, the paper mainly deduces the improved secondary range compression algorithm which can resolve the great error caused by the line trajectory model. At last, the paper gives some simulation analyses: parameters choice is detailedly analyzed, the parameters matching importance is also shown, and some point targets' simulation results are given to verify the correction of the improved algorithm.