Radon transform based edge detection for SAR imagery

Edge detection in SAR images has always been a challenge due to the effects of random interference of coherent signal. Unlike optical images, boundary delineation of regions is relatively ineffective for SAR images. The usual edge detectors, successful with incoherent images, yield poor results when applied to radar images, especially those with a small number of looks. Radon spectrum can be used to find the local orientations in an image which embed the edge information [1]. In this paper, we demonstrate the capability of Radon transform to efficiently extract edges from a SAR image covering agricultural landform. One approach to edge detection in polarimetric SAR images is to perform the edge detection separately for each of the polarization channels and subsequently combine the results using a fusion operation [2] [3]. We have made use of HH, HV and VV channels and fused the edge maps of these individual bands with Boolean `AND´ operator. This type of fusion has preserved the prominent edge information reasonably while suppressing spurious ones.