Yague-Martinez, Nestor; Eineder, Michael; Brcic, Ramon; Breit, Helko; Fritz, Thomas (German Aerospace Center (DLR). Remote Sensing Technology Institute, Germany)
SAR image coregistration is of fundamental importance for accurate Digital Elevation Model (DEM) generation. In this paper the coregistration algorithm for the TanDEM-X Mission is presented. Because of the parallax, a range shift variation of several samples over range appears. The use of coregistration polynomials is not a suitable solution due to the high resolution of the system, therefore a new two-step algorithm is proposed: a geometrical a-priori shift estimation followed by an optimized signal-based method. Moreover, an outliers elimination module is described. Results with TerraSAR-X repeat-pass data are shown.