Predicting the propagation loss through a tree canopy at millimeter frequencies — Forward scattering approximation — 3-D vector radiative transport theory

The vector radiative transport theory is used to compute the attenuation produced by a tree canopy containing random located lossy-dielectric leaves and branches at millimeter wave frequencies. Using this approach, the forward scattering approximation is used to simplify the radiative transport equation. The forward scattering approximation is used since at millimeter frequencies, the leaves and branches are large and thick compared to the wavelength; hence, a leaf or a branch scatter energy strongly in the forward direction and weakly in all other directions. The leaves are modeled as flat-circular lossy-dielectric discs and the branches as lossy-dielectric cylinders with prescribe orientation statistics.