Advanced SAR Interferometric Techniques for Monitoring Nonlinear Volcanic Deformation – Test Site El Hierro Island

SAR Interferometric (InSAR) techniques are widely applied for analyzing geophysical and tectonic deformations and for improving modeling techniques, with the benefits of surface deformation measurements covering areas from several to a hundred kilometers in size with a satisfactory accuracy (theoretically in the millimeter range). Nevertheless the accuracy and availability of deformation measurements using InSAR techniques is limited due to decorrelation effects, atmospheric disturbances, the SAR sidelooking geometry (which causes layover and shadowing). In this paper, we will present advanced InSAR techniques combined with cross-correlation measurements [1] in order to retrieve non-linear deformation signals from active volcanoes using high resolution TerraSAR-X mission images. An experimental TanDEM-X Raw DEM with a resolution of approximately 6 meters has been applied in order to compensate the topographic phase. A volcanic test site which is currently highly active – El Hierro Island – has been selected in order to demonstrate the developed advanced techniques.