Abstract:
The variation of point refractivity gradient with time of the day as well as seasons provide information on the occurrence of multipath fading which often cause reduction in signal strength. There is therefore the need to plan around the worst month for both quick planning and detailed planning purposes as recommended by the ITU-R. This study made use of five-years satellite data (2010-2014) obtained from the archived data of the National European Centre for Medium Range Weather Forecast (ECMWF). The data comprised of temperature, relative humidity and pressure which were used to calculate the point refractivity gradient (PRG) and the geoclimatic factor K at different intervals of time. The results obtained showed that the values were higher at the morning hours (00 hr LT) than other times of the day. The results also indicated that the fade probability for the worst month was highest in Sokoto with a value of about 16% while the least value was obtained in Osogbo with fade probability of 0.37%. The implication of these results is that multipath fading is a more serious problem in Sokoto compared to other locations in the study area and that Sokoto is more likely to experience severe reduction in signal strength during radiowave propagation.
