Diurnal, Seasonal and Annual Variation of Microwave Radio Refractivity Gradient over Akure, South West Nigeria
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Date
2019-11
Journal Title
Journal ISSN
Volume Title
Publisher
Physical Science International Journal
Abstract
In this study, four years in-situ measurements of atmospheric parameters (pressure, temperature
and relative humidity) were carried out. The measurement was by placing an automatic weather
station at five different heights: ground surface, 50, 100, 150 and 200 m respectively on a 220
m Nigeria Television Authority TV tower in Akure, South Western Nigeria. The four years Data
collected (January 2007 to December 2009 and January to December 2011) were used to compute
radio refractivity and its gradient. The local effect of a location/ region cannot but looked into
when designing effective radio link, hence the diurnal, seasonal and annual variations of the radio
refractivity gradient were studied. Results showed that refractivity gradient steadily increases in the hour of 8:30 and 9:30 to 18:00 during dry season throughout the years investigated, and
decreases two hours in the rainy season than the dry season. The record shows that at 50 m
altitude, the maximum and minimum values are 158 N-unit/km around 14:30 and - 286 N-unit/km
around 13:30 to 14:00 hrs, LT during the dry and rainy season respectively. Seasonally, refractivity
gradient is steeper with greater variability in the dry season months than in the wet season months.
Description
Staff Publication
Keywords
Microwave;, radio;, refractivity;, refractivity gradient;, temperature;, relative humidity.