Automatic Detection and Positioning of Ground Control Points Using TerraSAR-X Multiaspect Acquisitions

Geodetic stereo synthetic aperture radar (SAR) is capable of absolute 3-D localization of natural persistent scatterers, 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 targets in SAR images of urban areas taken from different orbit tracks. Moreover, a complete workflow 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.