Abstract

In this study, the multipath fading occurrence in six cities in Nigeria is investigated using the geoclimatic factor approach and ITU-R recommendations P530-14. The cities considered for the investigation are Kaduna (10°20'N,7°45'E), Lagos (6.45°N,3.38°E), Abuja (9.07°N,7.39°E), Port-Harcourt (4.81° N,7.04°E), Enugu (13.00° N,5.24° E) and Kano (12.00° N,8.59° E) in Nigeria. Five-year radiosonde data is used in estimating the percentage of time that a certain fade depth is exceeded and hence outage probability due to atmospheric multipath propagation, assuming the given fade depth leads to the received signal falling below the squelch level. The Inverse Distance Square (IDS) technique was employed to estimate point refractivity gradient not exceeded for 1% of the time in the lowest 65 m above the ground for the selected six cities in the six geopolitical zones within Nigeria. Standard error of the mean and confidence interval for both annual average and seasonal average of point refractivity gradient is calculated to reflect possible deviation in the given readings. The values of point refractivity gradient obtained were used in determining the geoclimatic factor K. The results presented shows monthly, seasonal and annual variation of both point refractivity gradient and geoclimatic factor K. The results confirmed that the geoclimatic factor K is region based.

Keywords:

Geoclimatic factor, outage probability, radiosonde data, refractivity, refractivity gradient, troposphere meteorological data,

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The authors have no competing interests.

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