While radar interferometry has found application in areas as diverse as the study of ocean currents and generation of digital elevation maps, few studies of its potential to detect and quantify surface change have been performed. When an imaging platform makes several passes over a given site, a number of different interferograms representing different temporal and spatial baselines can be generated. The complex backscatter from a particular target can then be compared for the various images, and the effects due to the spatial baselines and noise levels removed. What remains is a measure of the ’’decorrelation” of the radar signals with time, which is indicative of changes in the surface occuring during the period of time spanned by the images.
John D. Villasenor,
Howard A. Zebker,
"Studies of temporal change using radar interferometry", Proc. SPIE 1630, Synthetic Aperture Radar, (12 May 1992); doi: 10.1117/12.59017; https://doi.org/10.1117/12.59017