Diurnal and Seasonal Variability of Radio Refractivity Over Coastal Nigeria

DOI

10.2991/978-94-6463-644-4_26How to use a DOI?

Keywords

Radio refractivity; Microwave communications; Signal propagation; Coastal region; Atmospheric fluctuations; Link reliability

Abstract

In this paper, one-year meteorological data from 2015 were obtained from the European Center for Medium-Range Weather Forecast (ECMWF) for seven stations located in the seashore region of Nigeria. The study focused on the diurnal, seasonal, and annual fluctuations of the Earth's atmospheric refractive index and their impact on radio signals operating at microwave frequency bands over these locations. Analyses revealed that variations in refractivity significantly influence the reliability, range, and quality of microwave signals. Maximum values of surface refractivity were observed during the disturbed period at midday (12:00 h LT), with values ranging from 405 to 420 N-units, while minimum values between 380 and 400 N-units were recorded during the quiet periods, particularly between 00:00 and 06:00 h LT and late evening at 18:00 h LT. Additionally, the results showed that higher refractivity values occurred during the wet season (March to May and October to November), associated with increased signal bending and enhanced propagation range. Conversely, lower refractivity values were observed during the dry season (December to February), resulting in reduced signal strength and range. These seasonal and diurnal trends indicate that atmospheric refractivity fluctuates proportionally with temperature and humidity changes, causing propagation anomalies such as multipath fading, ducting, and interference. Understanding these variations is crucial for the effective design and planning of microwave communication systems in regions with significant refractivity fluctuations. The study provides insights into the influence of climatic factors on signal behavior, which is essential for optimizing radio link performance in coastal regions.

Copyright

© 2025 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

Download article (PDF)

TY  - CONF
AU  - E. T. Omotoso
AU  - F. Olajide-Owoyomi
PY  - 2025
DA  - 2025/02/04
TI  - Diurnal and Seasonal Variability of Radio Refractivity Over Coastal Nigeria
BT  - Proceedings of the 8th URSI-NG Annual Conference (URSI-NG 2024)
PB  - Atlantis Press
SP  - 264
EP  - 275
SN  - 2352-541X
UR  - https://doi.org/10.2991/978-94-6463-644-4_26
DO  - 10.2991/978-94-6463-644-4_26
ID  - Omotoso2025
ER  -