Analysis of Interferometry Data (permanent Scatterers: Ps-Insar to Identify Active Tectonic Structures in Western Alps (nw Italy)

The SAR interferometer technique allows detecting small movements of the ground surface. One of the most effective is the Permanent Scatters (PS-InSAR) technique proposed by Ferretti et al., 2001. The PS are points on the ground (buildings, rocks, etc.) that show high long-term phase coherence, as well as strong and stable backscatter level through time. Since PS do not change their signature with time, they can be used to estimate the sub-vertical motion of the ground, within the range of millimetre motions/year (fraction of the 5.6 cm-wavelength). PS velocity values are relative to a chosen reference point that is assumed to be stable. Thirty-eight ERS1/2 SAR descending scenes, taken from 1992 to 2000, allow detecting over 2 million PS with a variable distribution density. This large data set required geostatistical and spatial cluster analysis (Hot Spot Analysis) that allowed generating maps of iso-kinematic ...