Horizontal propagation through periodic vegetation canopies

Experimental data suggest that a semideterministic technique is needed to model certain man-made vegetation canopies such as orchards, plantations, and row crops. A two-dimensional model has been developed to explain wave propagation through such canopies. The model is intended for media containing vertical cylinders, representing the stalks, and randomly oriented disks, representing the leaves. The formulation treats the canopy as a one-dimensional array of parallel rows, with each row comprising an array of parallel stalks and a random distribution of leaves. The quasi-static approximation used for computing scattering by the leaves is valid only when the dimensions of the leaves are smaller than the wavelength. The model is a field approach accounting for all coherent, multiple interactions occurring in the canopy. The experimental component of this study includes measurements of the attenuation and phase shift patterns for horizontally and vertically polarized waves transmitted through a fully grown canopy of corn plants observed at 1.5 GHz. The model has good agreement with the experimental results.<
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