Radiometric Accuracy and Stability of TerraSAR-X and TanDEM-X

The TerraSAR-X and the TanDEM-X satellite produce high quality SAR images for a number of scientific and commercial applications. To guarantee the stability of the high accurate SAR products both systems are permanently monitored over the full life time. This paper describes the applied methods and presents the latest results of Long-Term System Monitoring (LTSM) with the focus on radiometric accuracy and stability that include the gain and phase properties of the T/R modules, the antenna pattern checked by evaluating uniformly distributed targets and radiometric stability over permanently deployed point targets. The outcome demonstrates the remarkable performance of both systems since launch.