Evaluation of Some Secondary Radio Meteorological Variables for Line-of-Sight Applications over Some Locations in Nigeria

Reliable data on radio propagation is required to suggest useful models for radio-climatic study. Computation of some secondary radio parameters across ten locations in Nigeria was done to deduce their effects on Line-of-Sight links. ERA-5 data obtained from the archive of European Centre for Medium-Range Weather Forecast (ECMWF) comprising of surface air and dew temperature, atmospheric pressure and relative humidity covering eight years (January 2010 – December 2017) was utilized. The results show that average radio refractivity values during the wet season (343.4 N-units) was higher than the dry season (273 N-units) and radio refractivity gradient values increase as the wet season progresses. Mean effective earth radius factor (k-factor) for the period of study were 1.38, 1.34, 1.67 and 1.72 for the rainforest, mangrove swamp, Sudan and guinea savannah regions respectively. It was also observed that a distinct relationship exists between the geo-climatic factor (K) and the seasons of the year with a range of 2.2 ×10-5 to 1.0 ×10-4.