Impact of Anomalous Propagation on Communication Signals In Librivelle – Gabon Troposphere
Braimoh A. Ikharo1, Okpo U. Okereke2 and Jibril D. Jiya3
1Department of Electrical and Computer Engineering , Edo University Iyamho, Edo State, Nigeria
2Department of Computer and Communications Engineer , Abubakar Tafawa Balewa University, Bauchi, Nigeria
3Department of Mechatronic and System Engineering, Abubakar Tafawa Balewa University, Bauchi, Nigeria
Abstract: Radio ducting is a known problem in the coastal areas of the world where it is evident that they occur frequently and their probabilities of occurrence pose enough operational effects on current radio communication signals. In this work, Advance Refractive Effects Prediction System (AREPS) is employed to characterize the tropospheric condition of Libreville troposphere. The results showed that in Libreville, the altitude where pronounced ducting phenomenon occurs majorly is within the first 160m above sea level. More so, there is an increasing order of variability and well-formed duct layers. The mean thickness of the layer over which ducting conditions occurred is usually very small for near surface events and large for the upper tropospheric events. Duct presence is throughout the year and conspicuously varied all year round.
Key words: Refractivity, Ducting, Tropospheric layer, AREPS, Variability, Occurrence, Communication
I. INTRODUCTION
Over the years, there had been tremendous growth in the demand for wireless mobile communication networks and these networks are not without its’ problems and challenges. Radio waves that propagates through the atmosphere have shown to have remarkable behaviours as they encounter varying meteorological conditions proved by several research studies in tropospheric refractivity and refractivity gradient. Ducting behaviour has been attributed to the variations of the humidity, temperature and pressure that cause variations in the refractive index [26]. The resultant effect is increased fading on communication links and consequently decreased power levels at the receiver stations [22].