Change detection for bridges over water in airborne and spaceborne SAR data

The main advantages of SAR are the capability of imaging large areas in short time and delivering data at any day time and under nearly all weather conditions. This is especially important for disaster management and continuous long term monitoring applications. Key elements of man-made infrastructure are bridges. Especially for bridges over water, the SAR specific side looking imaging geometry can lead to special characteristics in the image. In this paper, the possibilities of extracting bridge features like width and height from SAR data, especially for bridges over water, are discussed. The feature extraction is based on the segmentation of parallel lines in an image. An approach is presented to exploit this feature extraction for change detection. The investigations are supported by SAR simulations, and real airborne and spaceborne data are presented.