UHF Propagation Through a Trunk‐Dominated Forest

Transport theory is used to calculate the intensity of a wave propagating though a trunk‐dominated forest. The trunks are replaced by parallel infinitely long dielectric cylinders, and a vertically polarized plane wave is normally incident on the layer of these randomly distribution parallel cylinders. The problem can be reduced to a two‐dimensional transport problem that can be solved by the eigenvalue technique for the coherent, incoherent, and total intensity of the propagating wave. Using the assumption that the distribution of trunks is sparse and that the trunks locations are independent from one another, the probability density function (PDF) of the total and incoherent intensity as a function of depth into the layer can be found. To verify these results, a Monte Carlo (MC) simulation is performed in the low frequency limit which takes the effect of multiple scattering into account. The results show that there is a very close correspondence between the transport and MC simulation findings; the coherent, incoherent, and the total intensity for these two methods agree very closely as a function of distance into the slab. In addition, the PDFs for these three quantities also agree with the MC based histograms. One sees that as the wave propagates into the layer, the Rician distribution for the magnitude tends to a Rayleigh PDF as the coherent wave decays.