Multipath propagation is one of the factors that cause radio signal degradation, and due to the irregularity in the atmosphere; this causes the variation in the point radio refractive gradient (PRRG) with height and time of the day as well as the season. In this paper, multipath propagation and fading in the coastal area of Nigeria is investigated, using five (5) years (Jan 2014-Dec 2018) re-analyzed data, obtained from the archives of European Center for Medium-Range Weather Forecasts (ECWMF). The primary atmospheric parameter; temperature, relative humidity, and pressure were obtained both at a surface and at 110 m height, for some selected locations in the coastal area of Nigeria; Badagry, Port-Harcourt, Ekeremor, Burutu, Ibeno, Ilaje, Akpabuyo. Point refractivity gradient, the Geoclimatic factor (K), fade statistics and the percentage of time that a certain fade depth leads to signal outage were estimated using the ITU-R P530-17 recommendation and Geoclimatic factor approach. The result show that the value of surface radio refractivity during the dry season months is higher than the values during the wet season months; this is attributed to the dry term of refractivity (Ndry). The cumulative distribution of refractivity gradient estimated shows that super-refractivity dominates in all locations considered. The result of PRRG and K factor further shows that the worst propagation condition falls mostly in the rainy season months except for Badagry and Ilaje that has their worst in the dry season.
Keywords: Geoclimatic factor, outage probability, point radio refractivity gradient, meteorological data