The Variability of Scattering from Leaves and Its Impact on Propagation

Models for the scattering of leaves is a key input into the current ITU-R recommendation P.833-9 for attenuation in vegetation. This paper examines the variability of scattering from leaves due to uncertainties in various parameters including leaf size, shape, curvature, inhomogeneity and moisture content. The resulting scattering amplitudes have been determined using numerical methods at frequencies of 1.9 and 26 GHz. The modelling assumptions made in current literature, backed up by measurements are reasonable up to around 10 GHz. However, at 20 GHz and beyond it is shown that some of these assumptions begin to breakdown.