An improved ratio edge detector for target detection in SAR images

Edge detection is usually an important step of speckled SAR image processing, such as target detection. A few ratio-based edge detectors, such as MRoA edge detector, and the RGoA edge detector using predefined thresholds, have been developed for speckled SAR images. In this paper, RGoA method is modified for target detection in SAR images. The algorithm of the modified version of RGoA (called MRGoA), and the method for automatically determining the ratio threshold are developed. The MRGoA method differs from the RGoA method in definition of an edge pixel and the automatic threshold determining method. A real SAR image is used to verify our method. Experimental results show that the proposed method is effective and it will facilitate target detection.