Publication IV Mika Karjalainen , Juha Hyyppä , and Yannick Devillairs

This paper describes the potential of Radarsat-1 fine beam intensity SAR images in urban mapping and change detection. The main objective was to determine the possibility of building detection e.g. as a function of height, orientation, roof material and roof type in the Helsinki metropolitan region. Altogether 22235 buildings were used to estimate the effect of height, and then 14270 buildings were used to estimate the effect of orientation. Additionally, a smaller and more detailed set of buildings was selected from various environments e.g. from forested and dense urban areas. It was shown that height and orientation were the main factors affecting on the detectability of the buildings. The results indicate that approximately 39% of the buildings can be detected using the Radarsat-1 SAR; densely build up areas are clearly visible in Radarsat fine beam images, but in small-house areas buildings that are surrounded by forest are visible only in very rare cases.