Uncertainty budget in snow thickness and snow water equivalent estimation using GPR and TDR techniques

Abstract. Snow water equivalent is a fundamental parameter for hydrological and climate change studies but its measurement is usually time consuming and destructive. Electromagnetic methods could be a valid alternative to conventional techniques, being fast and non-invasive. In this work we analyze the reliability of a combined GPR/TDR method to estimate snow thickness and snow water equivalent. To estimate GPR accuracy we perform a calibration test where measured and predicted radar data are compared in terms of two-way travel time. Furthermore we implement a complete analysis of the uncertainty budget in order to evaluate the "weight" of each uncertainty on the snow parameters computation chain. We found that GPR, supported by TDR data, is quite reliable as it measures snow thickness and snow water equivalent with an accuracy comparable to that of a traditional method but, in general, with a slightly larger uncertainty.