An electronic device for long-term snow wetness recording

Abstract

Water content, water distribution and variations with time of these quantities in the natural snow cover are important parameters for microwave remote-sensing studies, snow stability investigations and snow hydrology studies. The most promising method for snow wetness determination is the measurement of the dielectric constant at radio frequencies. Recent developments of electronic devices for long-term recording of snow wetness are reported. The measurement system consists of two parts: the tuning and display unit with the battery pack and the flat capacitive sensor. The system is controlled by a built-in low-power microcomputer, the operation frequency for the sensor is 20.00 MHz. Measurement data are displayed on an LCD and are also stored in a RAM; data transfer for a PC for further data processing is possible by a built-in V24 interface. Up to four individual sensors can be operated simultaneously. Field measurements of long-term variations in snow wetness during diurnal cycles and registrations of penetrating meltwater or rain-water waves with the formation of water shock fronts are presented.

Development of a snow wetness inversion algorithm using polarimetric scattering power decomposition model

“…In a similar way, the average snow surface coherency matrix (A.13) is given in terms of the generalized surface parameter (|ˇ| 2 ), (Denoth, 1994) to estimate the snow surface and the volume wetness.…”

Field measurements of snowpack response to explosive loading

“…In addition, snow density was measured in each of the three snow pits using a capacity probe (Denoth, 1994). Manual density was also recorded layer by layer if possible.…”

Development of an inversion algorithm for dry snow density estimation and its application with ENVISAT-ASAR dual co-polarization data

“…The most appropriate method for estimation of dry snow density is based on determination of dielectric constant at radio frequencies because in the range between 1 MHz and 10 GHz, the real part mainly depends on density. The dielectric constant of dry snow in the density range between 0.05 and 0.5 g/cm 3 has been studied by various authors (Cumming 1952, Ambach and Denoth 1972, Hallikainen et al 1982, Nyfors 1982, Tiuri et al 1984, Achammer and Denoth 1994, Denoth 1994, Matzler 1996. Various empirical and theoretical mixing models exist for the calculation of dielectric constant (e ¼ e 0 -je 00 ) for the dry snow (Hallikainen et al 1982, Denoth 1994, Tiuri et al 1984.…”