Comparing RADARSAT-1 and IKONOS satellite images for urban features detection

In this paper, a comparison of the visual appearance and detection of different man-made objects in an urban area in Norway is presented using IKONOS and RADARSAT-1 images. Results show that RADARSAT-1 fine mode images add very limited information to the IKONOS panchromatic image for many mapping applications. One explanation for the seemingly lack of information from the synthetic aperture radar (SAR) data, is that the IKONOS sensor image the Earth ground with a resolution of 1 m, while the RADARSAT-1 fine mode only has 9 m resolution. Despite these matters, it is shown that RADARSAT-1 may uniquely detect certain objects or structures and thereby give additional knowledge to the interpretation of an IKONOS image. Multi-temporal RADARSAT-1 acquisitions can also be used to detect man-made changes at times when weather conditions hamper optical image acquisitions. It is expected that new SAR satellites with resolutions down towards 1 m, work much better as a complementary, all-weather information source to the optical ones.