Snow Water Equivalent Evolution During the 2019/2020 Winter Period in Aemet-Formigal Test Site Using a SFCW Radar

Snow makes a great contribution to the hydrological cycle in cold regions. The parameter to characterize available water from the snow cover is the snow water equivalent (SWE). This paper presents a near-surface based radar for determining SWE from the measured complex spectral reflectance of snowpack. The method is based on a stepped-frequency continuous wave radar (SFCW), implemented in a coherent software defined radio (SDR), in the range from 150MHz to 6GHz. An approximate method to calculate SWE is proposed. Results are compared with those provided by a cosmic-ray neutron (CRN) SWE gauge over the 2019–2020 winter in the experimental AEMet Formigal-Sarrios test site. The results suggest the viability of the approximate method. Finally, the feasibility of an auxiliary snow depth measurement sensor based on a 120GHz radar FMCW sensor (mmWave sensor) is shown.