SRTM and beyond: current situation and new developments in spaceborne InSAR

Abstract

SAR interferometry (InSAR) has become one of the most powerful tools in radar remote sensing. Generation of digital elevation models, measurement of glacier flows and mapping of earthquakes, volcanoes and subsidence are the most prominent applications of InSAR. For most of these applications continuous acquisition of SAR data from space over many years, like with the ERS-1/2 or Radarsat, is indispensable, and a quality in its own. The unique Shuttle Radar Topography Mission (SRTM) demonstrated in 2000 the single-pass InSAR technology for global topographic mapping by generating a world-wide DEM of unprecedented resolution and uniform quality. A new generation of SAR satellites will be launched in the next three years: TerraSAR-X, Radarsat-2, SARLupe, COSMO-Skymed and ALOS. They embody a lot of novel features, such as higher resolution, polarimetry, splittable antennas, and spot-light imaging mode. These future SAR satellites systems and their potential are described after a review of the state of the art SAR and InSAR techniques and applications. Traffic monitoring by TerraSAR-X is highlighted as a particular application, where after new ideas for InSAR satellite constructions and configurations are discussed.