Spatial Interpolation for Mapping Geoclimatic Factor K in South Africa
A deep fading prediction technique is the most important element of practically all methods for estimating multipath outage probability on terrestrial microwave line-of-sight links(LOS).Most of these techniques are based on empirical fits of Rayleigh-type distributions to the fading data for individual countries and are characterized in terms of climatic conditions.ITU-R provides a global method for predicting the percentage of time that a certain fade depth is exceeded in the average worst month.Apart from link variables,the ITU-R method,has additional variable the geoclimatic factor K.This variable takes into account the variability of climate and terrain.It is recommended that the geoclimatic factor K be obtained from fading data in the vicinity links of the planned link if such data exist.However,since in most cases such data is not available,prediction methods based on refractivity gradient statistics are recommended.In this paper,geoclimatic factor K derived from radiosonde data for five locations in South Africa are used to estimate and map the values for all the regions in South Africa.Three spatial interpolation techniques: Kriging,Inverse Distance Weighting and Thin-Plate Spline are used in estimating the geoclimatic factor in places where data is not observable.Statistical assessment of these methods is done by calculating the mean absolute error(MAE)and the root mean square error(RMSE)between a set of control points and the interpolated results.The best performing method estimated values is used to map the seasonal geoclimatic factor K for the entire study region.The estimated values of geoclimatic factor will improve accuracy in predicting multipath outage in LOS links in the region.
M.O.Asiyo T.J.O.Afullo
Department of Electrical,Electronic and Computer Engineering University of KwaZulu-Natal,King George V Ave.,Durban 4041,South Africa
国际会议
Progress in Electromagnetics Research Symposium 2013(2013年电磁学研究新进展学术研讨会)
台北
英文
648-652
2013-03-01（万方平台首次上网日期，不代表论文的发表时间）