High Resolution Satellite Sar Focusing with Azimuth Periodically Gapped RAW Data

Azimuth periodically gapped sampling occurs in satellite Synthetic Aperture Radar (SAR) due to new radar mission or sensor geometries. For resolving this issue, a novel strategy is presented in this paper for obtaining high-resolution satellite SAR image via processing azimuth periodically gapped echo data by segmented recovery. To avoid azimuth frequency aliasing, the proposed method splits echo data into several sub-blocks in azimuth direction. Then, sub-blocks are compensated with curved orbit phase compensation function and recovered with iterative adaptive approach. Afterwards, sub-blocks are combined as the whole echo data in time domain. Subsequently, the recovered data is processed by curved orbit deramping-based approach and modified range migration algorithm. The proposed strategy is validated with simulation and actual SAR data experiment.