Mitigation of Positioning Bias in PSI Point Clouds

In this paper, we propose a framework for geocoding error correction of point clouds obtained from Persistent Scatterer Interferometry (PSI) in urban areas. The horizontal positioning bias of Persistent Scatterers (PS) is mitigated by applying geodetic and atmospheric corrections to the PS azimuth and range timings. Furthermore, the vertical positioning bias, caused due to the unknown height of the PSI reference point, is estimated and compensated for by the use of Synthetic Aperture Radar (SAR)-based Ground Control Point (GCP)s. Experimental results based on cross-heading pairs of TerraSAR-X (TS-X) high resolution spotlight images over the city of Berlin, Germany and in Oulu, Finland are presented. For selected test sites, the localization accuracy of the point clouds is analyzed with respect to a reference LiDAR data, which demonstrates the applicability of the proposed correction approach.