L1 network inversion for robust outlier rejection in persistent Scatterer Interferometry

Persistent Scatterer Interferometry (PSI) is an established SAR technique for the monitoring of the Earth´s surface displacement. In the framework of the ESA´s Terrafirma project, a Wide Area Product (WAP) PSI mapping is demonstrated by DLR. In this paper we address one of the technical difficulties in its development: the robustness of the reference network inversion. Outliers due to both falsely detected PS and the arc estimation process itself must be robustly handled. An approach based on the L1 norm network inversion for outlier rejection is proposed and evaluated.