Millimeter wave scattering and attenuation prediction from a canopy of a tree — Radiative transport theory

The radiative transport theory has been used to compute the attenuation produced by a canopy of a tree containing random located lossy-dielectric disc and branches at millimeter wave frequencies. Using this approach, the forward scattering approximation is used to simplify the solution of 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 modelled as flat-circular lossy-dielectric discs and the branches as lossy-dielectric cylinders with prescribe orientation statistics. Results show that by only considering the coherent intensity the excess loss is over estimated due to an ensemble of random located lossy-dielectric discs and branches.