Gnss-based Signal Path Delay and Geodynamic Corrections for Centimeter Level Pixel Local- Ization with Terrasar-x

Previous studies have shown the unprecedented absolute pixel localization accuracy of the German SAR (Synthetic Aperture Radar) satellites TerraSAR-X and TanDEM-X. Now, by thoroughly correcting the atmospheric signal path delays and geodynamic effects like tides, loadings and plate movements, range accuracies of about 1 centimeter are demonstrated to be attainable. While Global Navigation Satellite System (GNSS) data provide local correction values for the atmospheric delays, correction values for the geodynamic effects are based on the IERS (International Earth Rotation and Reference Systems Service) conventions. In order to verify the proposed correction approach, we set-up a long-term measurement series based on a corner reflector with very precisely known ground position which we installed at the Geodetic Observatory at Wettzell, Germany, close to the local GNSS reference site. Measurement series of further comparable high precision corner reflectors in Antarctica and Finland are in progress and shall prove the worldwide reproducibility of the achieved results.