Investigation of snow avalanches with ground based ku-band radar

Abstract

A ground based interferometric and fully polarimetric real aperture Ku-band system is used to observe snow avalanches and hazardous snowpack. The system’s high temporal resolution of three minutes allows for near real time monitoring of processes. Instantaneous coherence drop was successfully used to detect avalanches. In combination with geometrical features of avalanches and their theoretical flow paths, modelled by water flow down the slope, the coherence drop has the potential for a reliable near real time avalanche detector. Variations in the coherence drop over a warm spring day, where significant snow melt occurred, were analysed with different time intervals and could partly be correlated to temperature variations inducing snow melt and refreezing. However this first data analysis showed that other processes must be taken into account to fully explain the variations.