ABSTRACT
Refractivity values were derived from daily and monthly measurements of atmospheric pressure, temperature, and relative humidity conducted by the Nigerian Meteorological Agency (NIMET) in urban areas of the Niger Delta, including Akure, Benin, Asaba, Yenagoa, Port-Harcourt, Calabar, and Uyo. The study explored the impact of atmospheric parameters on refractivity, revealing a significant association with atmospheric pressure. During the dry season, an increase in atmospheric pressure correlated with a decrease in refractivity, while the wet season showed the opposite trend. Atmospheric temperature was identified as a noteworthy factor influencing refractivity, exhibiting a similar distribution pattern to refractivity values. Relative humidity also played a role, with lower humidity during wet season months generally corresponding to higher refraction values. The study further assessed effective earth radius factors, noting variations across seasons, with the highest value observed in March and the lowest during the peak of wet season months. These variations suggested that using the standard k-factor of 1.33 in these environments would not achieve the required antenna height for Line-of-Sight communication setup. Additionally, the study calculated refractivity gradients, finding variations across months in the Niger Delta, with super-refraction predominating in most months.
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