Characteristics Of Tropospheric Scintilation For Satellite Applications In Jos

This paper presents the results of the hourly variation of refractivity based on measurement of temperature, atmospheric pressure and relative humidity in Gold and Base, Jos (09°58’N, 008°57’E, 1192m), (near Air Force Military School-AFMS), Nigeria. Twelve months meteorological data were measured with DAVIS Vantage Vue weather station; and were used to compute the surface radio refractivity and the scintillation fade depth following the ITU-R P.834 prediction model. Correlation values showed that the average hourly variations of refractivity in the dry season remained low, mainly as a result of the low values of the wet component humidity; while the average daily values of surface radio refractivity in the rainy season varied mainly as a result of both variations in the dry (pressure) and wet (humidity) components of surface radio refractivity. Diurnal curves in the dry season showed minimum values in the mid-morning to late afternoons (10:00–16:00), and maximum values from evening to early morning hours (18:00-08:00); while the rainy season has a fairly constant average refractivity index of about 345 units. Seasonal values of surface radio refractivity varied between 276 and 330 units during dry season; while the values varied between.348 and 338 units during rainy season Also, scintillation fade depth ranged from 0. 95dB to 2. 05dB during dry season; and from 1. 788dB to 2. 20dB in the wet season. For future research, it is suggested that different single-parameter models could be developed for dry season and during the rainy season. While an inverse temperature-dependent model is required for dry season, a pressure-dependent model would suffice for rainy season.