Performance and experimental evidence of GPR in density estimates of snowpack

Ground probing radar (GPR) and microwave devices can be successfully used to analyse the structure and the density of the snowpack. The performances of standard radar systems for snowpack characterisation are analysed here; the main aim was to assess the reliability of the method for estimating snow density, snowpack thickness and the depth resolution in terms of capability of detecting thin layers. The main relationships between the electrical permittivity and the density of dry-snow are discussed; these relationships are applied to estimate the vertical density profiles inferred from GPR surveys performed at several test sites in the Italian Alps. The data are calibrated and compared with the results obtained from direct density and layer thickness measurements.