SAR positioning for geodetic applications revisited - Lessons learned from TerraSAR-X and Sentinel-1

Abstract

Synthetic Aperture Radar (SAR) satellite missions can determine the 3-D position of persistent radar targets in a similar way as GNSS does with precise point positioning (PPP). This geodetic SAR method relies on the inherent timing and ranging capabilities of SAR sensors and it works well across different sensors when using dedicated ground infrastructure such as passive radar corner reflectors. But there are many aspects involved that have to be carefully considered in the processing such as precise orbit products, timing calibration of the SAR instruments, geometric fidelity of the SAR image products, or the correction of observation errors caused by atmospheric path delays and solid Earth deformation signals. The presentation will summarize the method and discuss the progress made with missions TerraSAR-X and Sentinel-1 over the past years.