Prediction of Tropospheric Amplitude Scintillation for Accurate Design of Earth-Space Communication Link over Akure, Nigeria

摘要

Tropospheric scintillation is liable to spatio-temporal variation due to its dependence on meteorological parameters and link variables. The dynamics of variation must be comprehensively characterized to ensure accurate communication operations and improved Quality of Service (QoS). Three years of data obtained from contemporaneous measurement of Eutelsat W4/W7 satellite radio beacons and meteorological parameters were employed to develop a location-based scintillation prediction model over Akure Southwest Nigeria (7.17 degrees N, 5.18 degrees E, 358 m). Extensive analysis involving probability density and cumulative distribution functions and seasonal and diurnal variation was carried out using data spanning 36 months between January 2016 and December 2018. Tektronix Y400 NetTek spectrum Analyzer was used for satellite beacon measurement at 1-s sampling rate, while Davis Vantage Vue weather station was used to measure weather parameters at 1 min integration time. Results show that the standard deviation of scintillation log-amplitude (scintillation intensity, sigma(chi)) experiences highest and least variations during daytime and night time, respectively, and periods of strong scintillation cut across both dry and rainy seasons. The variation of sigma(chi) on diurnal scale was suitably described by GEV, gamma, and lognormal distribution models, while the developed models for scintillation intensity, enhancement, and fades performed excellently with high R-2 values and minimal RMS errors.