Ground Probing Radar (GPR) devices is adopted for the analysis of thickness and the mechanical properties (density) of the snow cover in some test site in Alps, in Northern Italy. The performances of standard radar systems for the snow cover characterisation are analysed, the main aim is to assess the reliability of the method to estimate the snow density, the snowpack thickness and the depth resolution in terms of capability to detect thin layers. The main relationships between the electrical

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... ermittivity and the density of the dry-snow are applied to estimate the density vertical profiles inferred by the GPR investigation. The data were calibrated and compared with the results coming from direct measurements of the density and thickness. Snow density and electromagnetic models: The density forming processes can be classified as primary, which develops at the snow surface either during deposition or by subsequent reworking from wind and secondary, which evolves on site subsequent to the deposition due to thermo-mechanical processes. The primary densification depends on the climate conditions, the precipitation rate, the size and type of snow crystals and the packing and disintegration of crystals by wind. The secondary densification results from volumetric creep due to normal and shear stresses and by the linked processes of heat and mass transport.