Tropospheric Influence on Low-band Very High Frequency (VHF) Radio Waves

The objectives of this study are to understudy the effects of temperature and relative humidity on low-band VHF signals, obtain a propagation model for signal transmission over Calabar and to ascertain the suitability of the free space propagation model for the study terrain. Results obtained shows that temperature and relative humidity has no effect on low-band VHF signals. The suitability of the free space propagation model for the study terrain failed, as calculated results underestimated path losses in the study area. Multiple regression analysis was used to obtain a suitable propagation model for the study terrain. However, since the studied meteorological variables has no effect on low-band VHF signals in the study area, the measured path losses could be attributed to foliage, hills, distance away from the transmitter and other components of the study terrain in which the signal is propagated.