Department of Electrical Engineering, Mangosuthu University of Technology, Umlazi, KwaZulu-Natal, South Africa
Owolawi, P.A., Department of Electrical Engineering, Mangosuthu University of Technology, Umlazi, KwaZulu-Natal, South Africa
The paper describes the modelling of the average rainfall rate distribution measured at different locations in South Africa. There are three major aspects this paper addresses: to develop a rainfall rate model based on the maximum likelihood method (ML); to develop contour maps based on rainfall rate at 0:01% percentage of exceedence; and re-classification of the ITU-R and Crane rain zones for the Southern Africa region. The work presented is based on five- minute rainfall data converted to one-minute equivalent using a newly proposed hybrid method. The results are mapped and compared with conventional models such as the ITU-R model, Rice-Holmberg, Moupfouma and Crane models. The proposed rainfall rate models are compared and evaluated using root mean square and chi-square (χ2) statistics. Then re-classification of the rain zone using ITU-R and Crane designations is suggested for easy integration with existing radio planning tools. The rainfall rate contour maps at 0:01% percentage of exceedence are then developed for South Africa and its surrounding islands.
Contour map; Conventional models; Hybrid method; ITU-R model; Maximum likelihood methods; Probability densities; Radio Planning; Rain attenuation; Rain zone; Rainfall data; Rainfall rates; Root Mean Square; South Africa; Cranes; Maximum likelihood estimation; Probability; Probability density function; Rain