Building façades reconstruction using multi-view tomosar point clouds

Rich scatterer information retrieved by very high resolution SAR tomography using multiple data stacks from different viewing angles enables us to generate 4D point clouds of the illuminated area from space. They can be potentially used for facade reconstruction and deformation monitoring in urban environment. In this paper, we propose an approach for façade detection and reconstruction from such point clouds. Firstly, the building façade points are extracted from the point density projected onto the ground plane. The extracted façade points are segmented into corresponding individual façades by means of orientation analysis. Surface (flat or curved) model parameters of the segmented building façades are further estimated. Finally, the elevation estimate of each raw TomoSAR point is refined by using its more accurate azimuth and range coordinates, and the corresponding reconstructed surface model of the façade. The proposed approach is illustrated and validated by examples using fused TomoSAR point clouds generated from two stacks of TerraSAR-X high spotlight images from both ascending and descending orbits.