Wide area persistent scatterer interferometry

The persistent scatterer interferometry (PSI) is a well established radar technique to monitor the Earth's displacements with millimetre accuracy. It uses men made features typically made of metal (persistent scatterers) given by chance to form interferometric phase time series spanning many years. Actually, its application is limited to urban areas only because of the high density of usable persistent scatters. In the course of ESA's Terrafirma project, a wide area product (WAP) PSI mapping is demonstrated by DLR. Subject is to map countries and continents based on the PSI technique. The WAP is foreseen to be a standard level 1 product for the future Sentinel-1 mission with its TOPS mode acquisition scenario. However, many technical problems need to be solved in order to extend the PSI mapping area from urban areas to rural and even mountainous regions. This paper reports on the wide area product, the technical challenges and their algorithmic solutions. Also, WAP example data are presented.