Propagation Trends of Radio Signals in Yola Metropolis, North-East Nigeria

Abstract

The propagation pattern of radio signals from the radio transmitter to the radio receivers as they pass through the transmission media is of great significance in the management and planning process of radio communication systems. With variable climatic factors, which are the main determinants of tropospheric propagation of radio waves, it becomes necessary to study these
variables for a considerable period of time to see if a trend could exist. To ascertain this trend, a ten-year (2009-2018) primary weather data from the Nigerian Meteorological Agency (NIMET) was used to calculate: refractivity (N), refractivity gradient (G), and k-factor for radio signals in the Yola metropolis. The results showed a sharp increase in the refractivity values during the
onset of the rainy season in May with a mean value of 1452.975 N-units/km. The refractivity gradient calculated at 190.5 m above the ground level showed an inverse relationship with the obtained refractivity values. The Computed k-values showed that, the radio signals within the study area propagated with a sub-refraction mean value of 0.946, less than the global standard value of 1.333 by the International Telecommunication Union (ITU).