Comparison of power fading models due to vegetation for a satellite-to-earth radiolink at Ku band

Experiments of scattering due to vegetation were conducted inside an anechoic chamber in the range from 8 to 18 GHz in order to validate the power fading estimation provided by some of the attenuation models found in literature. Our study considers diverse tree species and elevation angles between 20 and 40 degree. This setup simulates the transmission between a satellite/helicopter/HAP and terrestrial mobile devices, in which cases the trees are small and with short depth so producing a large radioelectric shadow. With the experimental results achieved, we probed the vegetation attenuation models with unsatisfactory results. This analysis shows that the contribution of vegetation depends on the tree type and shape. We conclude that the power fading models require to be improved to consider short propagation distances travelled through the vegetation medium.