Estimation of the Surface Velocity Field of Temperate Glaciers Using Airborne SAR Interferometry

Abstract

This paper presents a methodology to process airborne interferometric SAR data to measure surface velocity fields of temperate glaciers. First, a solution based on multi-squint is proposed to estimate residual motion errors (inaccuracies of the navigation system on the order of a few centimeters) in the case of non-stationary scenes. Afterwards, an efficient methodology to derive surface velocity fields with airborne systems is expounded, where the line-of-sight displacement is estimated using differential interferometry, and the along-track component by estimating the azimuth coregistration offsets. The necessary steps to finally obtain the 3D surface velocity field are also presented, as well as the possibility to combine different acquisition geometries. Airborne interferometric SAR data acquired by the Experimental SAR system of DLR over the Aletsch glacier, located in the Swiss Alps, are used to evaluate the performance of the proposed approach.