Estimation of building heights from detected dual-aspect VHR SAR imagery using an iterative simulation and matching procedure in combination with functional analysis

The new spaceborne very high resolution (VHR) synthetic aperture radar (SAR) sensors onboard the TerraSAR-X and COSMO-SkyMED satellites can achieve spatial resolutions in the order of 1 meter. In VHR SAR data, features from individual urban structures (like buildings) can be identified in their characteristic settings in urban settlement patterns. In this paper, we extend a methodology for the height estimation of generic man made structures from single detected VHR SAR imagery for dual-aspect data sets. The method is based on two subsequent steps. Firstly, the height of a building is estimated from the two aspects separately. Then, in a second step, the quality of each estimate is assessed. This information is used either to select one of the height estimates as final height assumption or to fuse the different height estimates to derive a new height assumption for the building. As test data we use dual-aspect VHR airborne SAR scenes and a pair of ascending and descending TerraSAR-X data, in which we analyze a set of 33 flatand gable roof buildings in a residential area in Dorsten, Germany. The airborne results show that by using an additional perpendicular flight path, some improvements in the accuracy of the height estimates can be achieved. However, combining the results from the satellite ascending and descending orbits does not yield any significant improvement compared to the estimation from a single scene.