Long Term Geodetic Monitoring Using Active C-Band Radar Transponders And Sentinel-1 - First Results

Reliable and accurate long term geodetic monitoring with SAR requires the installation of either passive corner reflectors or, alternatively smaller active devices. We report our first results using novel off-the-shelf transponders or electronic corner reflectors (ECRs) for geodetic measurements with Sentinel-1 C-band Synthetic Aperture Radar (SAR) data. For this purpose we set up a triangular arrangement consisting of one trihedral corner reflector and two active ECRs at the campus of German Aerospace Center (DLR) in Oberpfaffenhofen, Germany. We describe the practical aspects of such ECRs as well as first radiometric characteristics. Moreover, we present geometric accuracy numbers derived from imaging geodesy, i.e. absolute radargrammetric positioning, as well as from interferometric phase measurements.