Diurnal variation of 20 GHz amplitude scintillation intensity

Measurements of phase and amplitude scintillation of the 20 GHz B1 Olympus satellite beacon at 28.8 elevation have been performed in Guildford at the Centre for Satellite Engineering Research. The satellite beacon was sampled at 20 Hz every hour during a randomly selected 5 minute interval. Scintillation amplitudes were expressed in dB above 1-minute mean levels. The variance of scintillation amplitudes were calculated for each 1-minute measurement interval and the distribution of variances were classified by hour interval of day. The paper presents the results of the above measurements and analysis for the months of February and March 1993. Cumulative distribution of observed scintillation intensities are presented. This indicates levels of scintillation intensities higher than that predicted by the CCIR model which is based on measurements at lower frequencies. Diurnal trends of the results are discussed.