Deformation measurements using SAR interferometry: potential and limitations

Most applications of Synthetic Aperture Radar (SAR) make only use of the am plitude information in just one image. Interferometric SAR (InSAR) makes us e mainly of the phase measurements in two or more SAR images of the same sc ene, acquired at two different moments and/or at two slightly different loc ations. By interference of the two images, very small slant-range changes o f the same surface can be inferred. These slant-range changes can be relate d to topography and/or surface deformations. InSAR thus has the potential o f mapping centimeter-scale ground displacements over a region many tens of kilometers in size at a resolution of a few meters making it one of the mos t promising space-geodetic techniques for monitoring Earth's surface deform ations. The goal of this paper is to discuss some of the potential new appl ications of InSAR for the monitoring of deformations, and to show its major limitations. Some potential new applications of InSAR related to surface-c hange detection including earthquake and crustal studies, the monitoring of volcanoes and anthropogenic effects, and the monitoring of glaciers and ic e sheets are presented. The discussion on the limitations of InSAR for surf ace-change detection focuses on atmospheric perturbations and the problem o f temporal decorrelation.