A novel imaging algorithm for inverse-tops data processing

Inverse TOP (Terrain Observation by Progressive Scans) mode is a state-of-the-art SAR mode, which can realize both low and high azimuth resolutions conveniently, and alleviate the scalloping effect. This paper addresses a novel image formation algorithm to deal with inverse TOPS data processing with four steps. The first step is adopted the de-rotation in azimuth, which will avoid azimuth frequency superposition. Then, the precise focusing kernel is used. Due to the de-rotation operation, the sampling rate is changed that resulting the overlap in SAR image along azimuth direction. So, resampling operation is necessary after focusing, and the resampling rate is studied. Furthermore, the combination operation is implemented, which realizes the combination of sub-swaths. Finally, numerical simulations were implemented to verify the accuracy of the proposed imaging algorithm.