Determination of optimal SAR illumination aspects in built-up areas

The increasing resolution of SAR data opens the possibility to utilize such data for scene interpretation in urban areas. SAR specific illumination phenomena like foreshortening, layover, shadow, and multipath-propagation burden the interpretation. In this paper a high resolution LIDAR DEM is incorporated to determine the visibility of objects by a SAR measurement from a given sensor trajectory and orientation in an urban environment. Shadow and layover areas are detected by incoherent sampling of the DEM. By a variation of viewing angle and aspect a large number of such simulations are carried out. From this set a subset of a number of best simulations is determined for to two example tasks, namely the analysis of objects on roads and the detection and reconstruction of buildings. Dominant scattering can interfere large parts of the scene. Such strong backscatter can be caused by specular reflection on gabled roofs or double-bounce on corner structures at building walls and roofs. The approach is extended to the detection of such structures.