COMPUTATION OF RAIN-INDUCED ATTENUATION AT CENTIMETRIC WAVE BAND FOR SLANT PATH COMMUNICATION IN NORTH CENTRAL NIGERIA

Abstract

This paper examines five globally recognized rain attenuation models for slant path communication to compute the attenuation and identify the models required for optimal rain-induced attenuation prediction over Nigeria's North-Central region. The models considered are Garcia-Lopez, Svjatogor, Bryant, ITU-R P.618-9, and Simple Attenuation. These models have been evaluated for circularly polarized signals in the centimeter wave bands. The Lavergnat-Gole rain rate model was employed to transform the original 5-minute integration time rainfall data to a 1-minute integration time. Attenuation estimates for rain varied widely between 9 and 14 dB for the Ku-band and between 20 and 32 dB for the Ka-band at 0.01% of the time over a typical year. Furthermore, the calculations of the Garcia Lopez, Bryant, and ITU-R P.618-9 models generally agreed, while the Simple Attenuation and Svjatogor models consistently underestimated the rain-induced attenuation across the selected region and all time percentages.