Scalloping Suppression Method for ScanSAR Images Considering Azimuthal Correction Errors and Range Spatial Variant Characteristics

Scanning synthetic aperture radar (ScanSAR) is the dominant imaging mode of existing SAR satellites. However, in this mode, a burst operation is utilized, resulting in scalloping problems that significantly impact the quality of ScanSAR images. In response to the poor robustness and high complexity of existing denoising algorithms, and based on the analysis of the causes of scalloping, a scalloping suppression method for ScanSAR images that considers azimuthal correction errors and range spatial variant characteristics is proposed. First, estimating the azimuth antenna pattern (AAP) correction error by analyzing the alternating scalloping periods and intensities along the azimuth. Next, a cubic polynomial is used to fit the variation in the noise gain along the range. Then, scalloping is removed from both the azimuth and range. Finally, the performance of the method is validated via Gaofen-3 ScanSAR images of different scenes. The results demonstrate that the proposed method can effectively remove scalloping, adapt well to complex scenes, and retain image details.