Sistem: a New Approach to Obtain Three-dimensional Displacement Maps by Integrating Gps and Dinsar Data

In this paper we show a new technique, based on the elastic theory, to efficiently produce an estimate of threedimensional surface displacement maps by integrating sparse Global Position System (GPS) measurements of deformations and Differential Interferometric Synthetic Aperture Radar (DInSAR) maps of movements of the Earth’s surface. We propose a linear matrix equation which accounts for both GPS and DInSAR data whose solution provides simultaneously the strain tensor, the displacement field and the rigid body rotation tensor throughout the entire investigated area. The mentioned linear matrix equation is solved by using the Weighted Least Square (WLS) method thus assuring both numerical robustness and high computation efficiency. The approach is named SISTEM as an acronym of Simultaneous and Integrated Strain Tensor Estimation from geodetic and satellite deformation Measurements. A real case study with GPS and DInSAR measurements carried out on Mt. Etna in the period 2003-2004 is reported.