Measurement of Liquid Water Content in Snow from Density-Insensitive Microwave Attenuation

A measurement principle for determining liquid water content (LWC) in snow is presented that does not require a priori knowledge or separate measurement of snow density. LWC affects the imaginary part of the effective permittivity of snow, which is linked to microwave attenuation along a microstrip transmission line embedded in the snowpack, independent of snow density. By analyzing the attenuation over a range of microwave frequencies, the corresponding LWC can be inferred. Full-wave simulations indicate a sensitivity of approximately 2 dB per % LWC,while experimental results confirm the insensitivity to snow density, highlighting the potential for remote snow characterization.