Advanced Radar Imaging of Geophysical Flows

摘要

The dynamics of geophysical flows such as snow avalanches and pyroclastic flows are of great interest, not least due to their potential for catastrophic consequences, and have received substantial attention over recent years. A variety of models have been formulated to predict the behaviour of such flows but there is currently a lack of suitable experimental data to validate these models and inform the choice of model or coefficients for a given situation. Radar measurements are useful in, for instance, observation of snow avalanches in order to provide velocity vector information of the movements of snow below the powder cloud, thus providing information that is not available using optical instruments. Simple radar observations, consisting of a one-dimension range profile of low resolution, have been made of snow avalanches. This work sets out to develop and utilize a more sophisticated radar instrument able to perform high resolution 3-D images of, in particular, snow avalanches but also pyroclastic flows, in order to provide a step improvement in the observational data with which to compare with a range of flow laws.