Urs Wegmuller
CEO
GAMMA Remote Sensing
Switzerland

Biography
Urs Wegm?ller received the M.S. (1986) and Ph.D. (1990) degrees in physics from the University of Berne, Switzerland. In 1995 he was a Founding Member of GAMMA Remote Sensing AG (GAMMA). GAMMA is specialized in radar signal processing and microwave hardware, sells licenses for its advanced SAR/InSAR data processing software and microwave hardware, and provides related services. As CEO of GAMMA Urs Wegm?ller has overall responsibility for GAMMA's activities. At present his main involvement is in the development of applications and the definition and implementation of related services in land surface deformation, hazard, landuse, and topographic mapping.

Abstract
Satellite SAR interferometry for ground deformation monitoring

With the launch of ERS-1 in 1991 repeat-pass satellite SAR data suited for interferometry (INSAR) became easily available. From its foundation in 1995 the Swiss Company Gamma Remote Sensing has been involved in the development of related processing techniques, applications, and services. Of particular interest is ground motion mapping. Using satellite SAR interferometric techniques it is possible to map and monitor ground displacements with mm precision. Important advantages of the methodology are the availability of suited data archives over many areas, the high precisions achieved and the wide area coverage possible. The main limitations are temporal decorrelation and path delay effects. In specific projects the primary use is often in a wider area assessment of ground stability. Nevertheless, more detailed local investigations an monitoring are also possible mainly thanks to the more recent high resolution SAR sensors that became available. After a short introduction of the methodologies used results achieved in different application domains will be presented and discussed.