The need for environmental monitoring is increasing with climate changes and natural resources exploitation, but the monitoring possibilities are also improving with the technological development enabling high spatial and temporal resolution. In this thesis, we address the accuracy and use of interferometric ground-based radar for detecting and monitoring of sub-millimetre surface displacements for geotechnical applications. We have focused on monitoring of rock slope failures, and glacier flow and calving events. We have used two different radar-systems in these two applications. The radar used to monitor rock slopes has a real aperture antenna, while the radar used for glacier flow monitoring has an electronically steered phased-array antenna. The latter makes it possible to scan the surface of the glacier with high temporal and spatial resolution. Both radars are designed and implemented by the radar company ISPAS AS. The radar used for mountain monitoring was developed and installed before this Ph.D.-project was undertaken, but the electronic scanning radar was built during this thesis. The design and development of the radar is not addressed this thesis
