Statistical modeling of rainfall effect on a foliage propagation path

Statistical modeling of rainfall induced temporal variations in a foliage channel at VHF frequency is performed in this paper. With the help of the Akaike weight omega_j, Weibull and Rayleigh functions are identified as the two suitable models to describe the tap amplitude variations. The Weibull function is then used as the channel model to analyze the rainfall induced temporal variations in a foliage channel. With its Weibull b parameter, the effects of rainfall is compared and studied. It can be concluded that, the free space propagation of the lateral waves over the treetops at VHF frequency is not affected by the rainfall. However, the through-foliage scattered components are significantly affected by the falling rains. This can be observed from the Weibull b parameter which decreases from 14 to 6, and even further down to less than 2. Therefore, when performing wireless system design in the forest environment, rainfall is an important factor that influneces the radiowave propagation and should be taken into consideration.