A ground-based real-aperture radar instrument for differential interferometry

Radar differential interferometry was initially developed using satellite SAR sensors due to the requirements for precise control and knowledge of the interferometric baseline. The development of ground-based radar imaging systems extends this technology to obtain essentially continuous deformation measurements at high spatial resolution. Applications requiring near real-time deformation measurements such as monitoring of landslides, glaciers, and mining can benefit from this technology. We describe a real-aperture ground-based radar system operating at 17.2 GHz developed by Gamma Remote Sensing. Results for observations of landslides, glaciers and a dam in the Alps are presented. Sources of positional and deformation error including decorrelation and atmospheric phase delay along with strategies for reduction of these errors are discussed.