Robust Image Registration Technique for SAR Images

Synthetic aperture radar (SAR) images are difficult to register with other images or maps of the same area because SAR images are corrupted with image speckle. The geo-reference of the image is conventionally realized by manual identification of ground control points (GCPs) and image rectification. There are two main tasks to geo-reference the SAR images. First one is to enhance the quality of images, reducing the noise and detecting the edges of the objects in the images to mark more clear points that are used as GCPs. The GCPs do not change with time and change in climatic conditions. The edges always remain same and can not be changed for a long time. This paper investigates the procedure for geo-referencing temporal images acquired for the same region by automatic identification of GCPs on the image by template matching technique. The procedure to extract high quality edge contours from SAR images and the process of automatic image-to-image and image-to-digitized map registration of SAR images has been presented