Results of comparative measurements of radiowave attenuation in snowfalls at frequencies 138 and 247 GHZ

We performed comparative quasi-synchronous measurements of radiowave attenuation by snowfalls on a close-to ground radio ray path of 1025 m long at frequencies 138 and 247 GHz. We showed that during some periods of a snowfall there is a stable, almost functional correlation between the attenuation coefficients at frequencies 138 GHz (Γ(138)) and 247 GHz (Γ(247)). In two of six recorded events such a correlation persisted during the entire snowfall. There were some occasions when the relationship between Γ(138) and Γ(247) had a “hysteresis” form. Analysis of all the data as a whole showed a linear correlation between Γ(138) and Γ(247) with a correlation coefficient of about 0.97. The average value of the ratio Γ(247)/Γ(138), which characterizes the frequency dependence of wave damping in snowfalls, was found to be equal to 3.8, its measured values being in the range between 1.6 and 6.2. Results of the experiment are compared with data from other measurements.