Tropospheric scintillation in the 14/11-GHz bands on Earth-space paths with low elevation angles

Radio waves with frequencies above 10 GHz at low-elevation-angle paths are significantly affected not only by rain but also by atmospheric irregularities in the troposphere. The tropospheric scintillation due to irregularities of the refractive index in the troposphere is investigated using 14/11-GHz low-elevation measurements made during 1983 at Yamaguchi, Japan. The diurnal and seasonal variations, frequency dependence derived from a comparison of the 11- and 14-GHz signals, and elevation-angle dependence of the scintillation data are presented. A comparison between the propagation data and ground-level meteorological measurements indicated a high correlation between the scintillation characteristics and the water vapor contribution to the radio refractive index inferred from local humidity and temperature data. This suggests a method for predicting the severity of scintillation fading using local measurements of meteorological parameters