Estimation of coherent field attenuation through dense foliage including multiple scattering

Single-scattering theory is shown to be insufficient for the estimation of effective propagation constant in foliage at high microwave and millimetre-wave frequencies. Clusters of broad leaves and needles are treated as a unit scatterer whose ensemble forward scattering is used in Foldy´s approximation to estimate attenuation rate in foliage. It is shown that single-scattering approximation overestimates forward scattering as high as 3-4 dB at 35 GHz.