An Azimuth Ambiguity Suppression Method Based on Ambiguity Focusing for SAR-GMTI.

Ground moving target indication (GMTI) is one of the important applications of synthetic aperture radar (SAR). Due to the finite pulse sampling rate in azimuth, the azimuth ambiguity appears in spaceborne SAR systems, which not only reduces the image quality but also affects the accuracy of moving target detection. The existing ambiguity suppression methods cannot retain moving targets which are overlapped with ambiguity, or cannot suppress the ambiguity in SAR-GMTI. To overcome the shortcomings of existing methods, this letter proposes an effective azimuth ambiguity suppression method based on local azimuth ambiguity-to-signal ratio (AASR) estimation and ambiguity focusing for SAR-GMTI. This method can effectively suppress the ambiguity and is applicable to the situations where the moving target is overlapped with the ambiguity, large scenes, and higher order ambiguity. Finally, the effectiveness of the proposed method is verified and demonstrated by the experimental results on GaoFen-3 SAR. [ABSTRACT FROM AUTHOR]