Tropospheric Scintillation Fading Analysis of Alphasat Satellite Measurements in Ka and Q Bands

Tropospheric scintillation of signal is caused by rapid fluctuation of refractive index due to random changes of humidity, pressure, and temperature in clear air, clouds and precipitation particles. The refractive index is continuously changing along the propagation path, causing random fades and enhancements in the signal level. In the system design phase, the prediction of long-term statistical distributions of signal fades and enhancements are needed. Long periods of measurement data are needed to characterize and model the scintillation statistics. In this paper, annual, seasonal and monthly statistical analyses of the scintillation fades based on the three-year beacon measurements of the Alphasat satellite at 19.7 GHz and 39.4 GHz in Ljubljana, Slovenia, are presented. The annual curves are also compared with the scintillation fades predicted by the ITU-R P.618-13 model.