Phase shift of the electromagnetic waves due to dry snow

Based on the point matching technique, the phase shift of the electromagnetic waves due to dry snow is computed. The analysis is restricted to the forward-scattering direction from oblate spheroidal dry snow. Numerical results are obtained for two orthogonal polarizations of the incident wave. The calculations are made for various microwave frequencies, between 6 and 100 GHz, and also for different precipitation rates, between 0.5 and 3 mm/hr. The effect of the frequency and the precipitation rate on the phase shift is examined. It is found that at a fixed value of the precipitation rate, the phase shift of both polarizations decreases with increasing frequency. It is also observed that at a fixed frequency, the phase shift of both polarizations decreases with increasing precipitation rate. The differential phase shift is found to follow the same trend as the phase shift for frequencies greater than 20 GHz and are negligible for frequencies below 20 GHz. In addition, it is found that the phase shift of snow decreases with snow wetness for fixed precipitation rate and frequency.