SAR Interferometry for Volcano Monitoring: 3D-PSI Analysis and Mitigation of Atmospheric Refractivity.

Abstract

Space-borne synthetic aperture radar interferometry provides a powerful tool for the monitoring of active volcanoes by surveying the surface changes at a theoretical accuracy in the millimeter-range. This accuracy is practically limited by effects such as temporal decorrelation, atmospheric distortions or phase unwrapping errors. The main concern of this thesis is to develop advanced SAR interferometric techniques in order retrieve reliable surface deformation signals. The persistent scatterer interferometry multi-temporal method is investigated and demonstrated for rocky volcanoes using TerraSAR-X high resolution SAR data. An effective method for the mitigation of the atmospheric delay effect due to vertical stratification in interferometric phase measurements is developed: the direct integration method. A multi-track fusion algorithm based on the iterative closest point algorithm is proposed for the geometrical fusion of PS clouds from different viewing geometries in non-urban areas.