This study undertakes the determination of suitable cutoff frequency for extracting scintillation amplitude dataset from radio propagation beacons on satellite link within Akure (7.17°N, 5.18°E), Southwest Nigeria. Attempt was also made towards evaluating the spectral characteristics of scintillation parameters through power spectra density (PSD) analysis. Concurrent measurement of satellite beacon signals and meteorological parameters was carried out on Earth-space path over the location for tropospheric amplitude scintillation studies. Tektronix Y400 NetTek Analyzer and Davis Vantage Vue weather station were used for beacon and weather parameters measurements at 1 second and 1 minute integration times respectively. Data spanning one (1) year of measurement were used for the investigation. Results show that extra contributions to signal distortions by non-scintillation mechanisms during extraction of scintillation dataset from satellite radio beacon series may be eliminated by using a cutoff frequency, f c of 0.25 Hz for high pass filtering. Also, spectral slopes with lower magnitudes were found to occur more predominantly than those with higher magnitudes.

In the lower part of the atmospheric boundary layer, structure of the radio refractive index plays a vital role when planning and designing microwave communication link. The effects of primary radio climatic parameters on radio wave propagation at UHF and microwave frequencies are crucial in studying radio refractive index. 1951 to 1980 satellite data has been used to investigate the mean values of both the primary radio climatic variables and surface radio refractive index over the Africa. The mean value of water vapor pressure, temperature and pressure ranges from 3-23 mbar, 284-302 K and 800-1000 mbar respectively across Africa. The high values of water vapor pressure around the Coastal and Rainforest reduce towards the Savanna and Steppe region (semi-arid). The mean variation value of surface refractivity over Africa ranges from 160 - 340 N-units. The refractivity values in larger part of the savanna range between 250 – 280 N-units.

Satellite communication systems suffer from the systematic error of tropospheric delay. Accurate estimation of this delay is essential for communication budget and planning. This study investigates the tropospheric delay in three Nigeria cities: Abuja, Lagos, Port-Harcourt using two different models (Saastominen and Hopfield). Three year atmospheric data for surface pressure, relative humidity and temperature obtained at 5-mins interval were acquired from the Tropospheric Data Acquisition Network (TRODAN) archives. Computed radio refractivity values showed distinct seasonal dependence in Abuja with low and high values during the dry and wet season respectively. The Hopfield model predicts higher hydrostatic delay values than the Saastominen model. In the non-hydrostatic delay, the two models converge to a single values at high temperature. Theorems were proposed with proofs to explain the relationship observed between the two models.