Evaluation of Vertical Refractivity Profile over Microwave Link in Mowe, Nigeria

The radio refractive index structure of the lower section of the atmospheric boundary layer is critical in the planning and construction of microwave communication connections. This study analyses the refractivity profile carried out in Mowe (6.8085° N, 3.4367° E) South – Western Nigeria. Ground measurements of air pressure, temperature, and relative humidity used in this investigation were collected from the rain gauge of the Tropospheric Observatory Data Acquisition Network (TRODAN). The radio refractivity, associated refractivity gradient and climatic factor were computed using data from January 2012 to December 2013. The vertical distributions of radio refractivity were then calculated using these parameters. Seasonal fluctuations in refractivity are visible over the location, with high values in the wet season and low values in the dry season. The findings also suggest that propagation circumstances fluctuate in frequency, with sub-refractive situations being most common between April and September. This is an indication that microwave link in Mowe will suffer higher signal loss during wet season, while the loss may be mild during the dry season. The refractivity values in this study are expected to aid in determining the necessary mitigation to be put in place to reduce loss of signal in Mowe.