Influence of Geoclimatic Factor on Fade Depth for Wireless Link Design using Radiosonde Data

International Journal of Research and Innovation in Applied Science (IJRIAS) | Volume V, Issue IX, September 2020 | ISSN 2454–6186

Influence of Geoclimatic Factor on Fade Depth for Wireless Link Design using Radiosonde Data

Aremu Olaosebikan Akann^1*, Mufutau Jelili Adekunle^2
*1 Physics Department, The Polytechnic, Ibadan. P.M.B 22, UI Post Office, Oyo state, Nigeria
²Physics unit, General Studies Department, Federal School of Surveying, Oyo. P.M.B. 1024, Oyo, Nigeria
Corresponding Author*

Abstract: The concept of fading and signal propagation design remain very vital to a radio Engineer because of the unstable nature of environment the signal traversing. Precise estimation of Geoclimatic factor (K) and effective earth’s radius factor (k) which depends on temperature, relative humidity and pressure are highly essential for radio signal propagation in clear air so as to provide for fade margin. In this work, the Geoclimatic factor has been obtained using Radiosonde data for two different locations (Ibadan and Ilorin), Nigeria. The K-factor obtained was used to determine the multipath fade depth exceeded for 0.01% of time and the result revealed that the k and K have monthly variations and they are locations dependent. Specifically, Ibadan and Ilorin has annual mean geoclimatic factor of 0.000293 and 0.000185 respectively. Also, the annual mean k-factor obtained in the two locations are 1.475 and 1.548 respectively. These values are higher than the standard value of 1.33 as predicted by ITU-R and the implications of the result is that, propagation in this geographic locations are mostly Super-refractive. From the monthly and annual K-factor presented, the percentage of time a given fade depth exceeded for the 20 GHz increases rapidly with increasing link distance in the two locations and the fade depth also increases with increase in frequency at a fixed distance. This is due to the fact that as the path length increased, the multiple reflections leading to multipath also increases and this leads to multipath fading. The overall results can be used for microwave link design in these locations.

Key words: Fade depth, Frequency, Geoclimatic factor, k-factor, Radiosonde.

I. INTRODUCTION

The propagation of electromagnetic waves around the earth is influenced by the properties of the Earth and the atmosphere [1-5]. Therefore, an appropriate planning is required or needed for effective radio wave propagation of terrestrial radio links for effective communication

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