Tropospheric Influences on Satellite Communications in Tropical Environment: A Case Study of Nigeria

Among other atmospheric regions, ionosphere, which is ionized region of the atmosphere, is considered to impose serious limitations on satellite communication while the effect of other layers, more especially, the troposphere is often treated as negligible. At higher frequencies, radio waves pass through the ionosphere and are attenuated due to the free electrons present in ionosphere. However, recent studies have shown that while the ionospheric disturbance can be predicted on global scale, tropospheric disturbances is depend on geographic location due to dependence of local meteorology on surface topography and other location specific weather forcing. This paper discusses the tropospheric effects on high frequency radio waves, especially, microwave band, illustrating the attenuation and losses it may come across like attenuation due to atmospheric gases, rain, clouds, beam spreading loss (radio refractivity) and noise temperature. Results from some previous studies over Nigeria was used to illustrated location dependence of tropospheric effects such as attenuation due to atmospheric gases, rain, clouds, beam spreading loss (radio refractivity) and noise temperature. Data used to summarize the influence of atmospheric phenomena was obtained using Vantage Pro 2 automatic weather station. ITU-R models were employed to processed data using MATLAB and Microsoft Excel. Results from the studies shows that tropospheric influence on satellite communication is very significant and more research should be carried out in this field.