Assessment of slow deformations and rapid motions by radar interferometry

Space-borne Synthetic Aperture Radar (SAR) interferometry is a powerful tool for measuring movements on ground by exploiting phase differences of SAR images taken at different time instances. Two technologies and their applications are described: 1) The persistent scatterer technique uses stacks of typically 100 images taken over up to 10 years for assessing slow deformation processes, e.g. land subsidence, at an accuracy of better than 1 mm/year. 2) Along-track interferometry is used to measure the velocity of vehicles for traffic monitoring. The potential of TerraSAR-X, the German radar satellite to be launched in 2006, for interferometry is discussed.