Analysis of Field Strength Variability at Ultra-High Frequency and Maximum Angle of Incidence across the Sahelian and Midland Regions of Nigeria

1,3*Davidson Odafe Akpootu., 2Gazali Bello., 3Isah Ibrahim Garba., 4Mudassir Na-Allah., 1Jabir Muhammad., 5Maryam Balarabe., 6Abdulsemiu Oluwatoyin Aina and 1Abba Babagana

1Department of Physics, Usmanu Danfodiyo University, Sokoto, Nigeria
2Sultan Abdurrahaman College of Health Technology Gwadabawa, Sokoto State, Nigeria
3Department of Physics with Electronics, Federal University, Birnin Kebbi, Nigeria
4Department of Physics, Abdullahi Fodiyo University of Science and Technology, Aliero
5Nigerian Postal Service No 10, Maputo Street Wuse Zone 3, Abuja
6Department of Physics and Materials Science, Kwara State University, Malete, Nigeria

*Corresponding author’s Email: davidson.odafe@udusok.edu.ng, doi.org/10.55639/607.02010071


ABSTRACT

Ultra-High Frequency (UHF) is the International Telecommunications Union (ITU) designation for radio frequencies between 300 MegaHertz (MHz) and 3 GigaHertz (GHz). In this study, the Field Strength Variability (FSV) at UHF and the maximum angle of incidence was estimated using the measured monthly climatic data obtained from the National Aeronautic and Space Administration (NASA) during the period of forty-two (42) years (1981 to 2022). The two climatic zones considered in this study are the Sahelian and Midland regions with two locations in each; Sokoto and Maiduguri, in the Sahelian region; Bauchi, and Jos in the Midland region. Using equation (8), the evaluated average radio refractivities at the operating frequency of 315.9 MHz were obtained to be 314.2398 N – units, 307.9401 N – units, 311.2480 N – units and 296.6702 N – units respectively. The findings indicated that for the four locations, the maximum average values of FSV at UHF obtained were 0.5583 dB, 0.3592 dB, 0.4654 dB and 0.0126 dB, which occurred in the rainy season, the positive values observed indicate a strong signal with good reception quality while the maximum average values of angle of incidence measured were 0.6204º, 0.6266º, 0.6592º, and 0.5820º for Sokoto, Maiduguri, Bauchi, and Jos respectively. The average maximum angles of incidence were found to be 0.5749º, 0.5243º, 0.6404º and 0.5696º for the locations during the studied period and are within the range of reported values (0.5º – 1º). The optimal angle of incidence values obtained in this study suggests enhanced signal strength and broader coverage areas for the four locations under investigation.

Keywords:

FSV,
Maximum angle,
Midland zone,
Sahel Savannah