An efficient tomographic inversion approach for urban mapping using meter resolution sar image stacks

This letter describes an efficient approach of multidimensional synthetic aperture radar (SAR) imaging for urban mapping. The proposed approach is an integration of tomographic SAR inversion and the well-known persistent scatterer interferometry (PSI). It consists of three steps: first, a global estimation of the topography and motion parameters using efficient algorithms such as PSI; second, a single and double scatterer discrimination step based on the results of the first step; finally, a tomographic SAR inversion, which is performed on the preclassified double scatterers, using the prior knowledge obtained in the first step, retrieving the topography and motion parameters of both scatterers. The proposed approach has been tested on a dozen of TerraSAR-X high-resolution spotlight image stacks. In this letter, examples from Las Vegas and Berlin are presented. The results are comparable with the one obtained by the most computationally expensive tomographic SAR algorithms (e.g., SL1MMER) only and saves computational time by a factor of 50.