Estimating Strain and Rotation From Wrapped SAR Interferograms

This letter aims to discuss a general framework that allows the direct interpretation of the wrapped differential synthetic aperture radar interferometry phase in terms of surface strain S and rotation R components. The methodology is demonstrated showing the estimation of strain and rotation components of a glacier flow using three TerraSAR-X interferometric geometries (ascending right-looking, descending right-looking, and descending left-looking). Finally, since the left-looking geometry can be difficult to obtain on a regular basis, the surface parallel flow assumption is extended to the phase gradients inversion in order to reduce the amount of necessary geometries from three to two.