An Improved Azimuth Ambiguity Suppression Method for SAR Based on Ambiguity Area Imaging and Detection

In this article, an azimuth ambiguity suppression method based on ambiguity area imaging and detection is proposed, which is suitable for various imaging modes such as strip, spot, and multichannel modes. The basic idea of this method is to focus the image of each azimuth ambiguity area of a single-look complex synthetic aperture radar (SAR) image through a reversible signal processing method, then the strong targets in the focused ambiguity area are detected and eliminated. Finally, the real target image in the main area is obtained through the inverse operation. This method can remove most of the azimuth ambiguity while maintaining the quality of the original image to the greatest extent. In this article, the method of segmentation of complex background and pure background is used to eliminate the error caused by single threshold detection, and the construction of ambiguity area focusing filter in spotlight mode and multichannel mode is studied. This method has good performance in engineering applications. The processing results of real spaceborne SAR images show the effectiveness and validity of the method.