Automatic positioning of SAR ground control points from multi-aspect TerraSAR-X acquisitions

Geodetic stereo SAR is capable of absolute 3-D localization of natural persistent scatterers (PS)s which allows for Ground Control Point (GCP) generation using only SAR data. The prerequisite for the method to achieve high precision results is the correct detection of common scatterers in SAR images acquired from different viewing geometries. In this contribution, we describe three strategies for automatic detection of identical point targets in SAR images of urban areas taken from different orbit tracks. Moreover, a complete work-flow for automatic generation of large number of GCPs using SAR data is presented and its applicability is shown by exploiting TerraSAR-X high resolution spotlight images over the city of Oulu, Finland and a test site in Berlin, Germany.