Comparison of RADARSAT and IKONOS satellite images - detection and visibility of man-made objects

This report compares the visual appearance and detection of different man-made objects in an area close to Bergen city in Norway using IKONOS (1 m resolution) and RADARSAT (9 m resolution) images respectively. The results show that the RADARSAT images add very limited information to the IKONOS panchromatic image for many mapping applications. One explanation for the seemingly lack of information from the SAR data in this study, is that the IKONOS sensor image the Earth ground with a resolution of 1 m, while the RADARSAT Fine mode only has 9 m resolution. Despite these matters, this study also shows that RADARSAT may sometimes uniquely detect certain objects: some buildings gave a strong backscatter even if they were partly hidden in the forest, buoys may very well be detected on a low SAR backscatter ocean surface, parked helicopters and airplanes were represented as bright points, electrical wires laid out in a direction favourable to the incidence radar beam. There are also examples that strong RADARSAT backscatter may confirm the presence of bridges as well as building structures/forms already seen in the IKONOS image.