Estimation of Radio Refractivity from a Decade Satellite Derived Meteorological Data for West Africa

Radio refractivity, which is the bending of radio signal as it propagates through media, is very important in works involving terrestrial atmospheric electromagnetic propagation such as point-to-point microwave communication, terrestrial radio and television broadcast, mobile communication system, and so on. This study has focused on the West African region where it was found that the region has a refractivity which varies exponentially with height and from the coast towards the desert. Generally, refractivity gradient was found to range between -46.48 and -29.51 N-units/km (k-factor value of between 1.23 and 1.42) across the region, splitting the between sub- and super-refraction. The variation in refraction type was found to follow seasonal pattern across the West African region, with sub-refraction dominating during dry season and super-refraction dominating most part in the coastal area during the wet season.