Comparison Results of Calculating the Radio Wave Propagation Using the Parabolic Equation Method in a Plane-layered Forest Model and in the Constructor of Individual Trees

When researching the mechanisms of propagation of radio waves inside the forest, there are two main approaches. The first is a mathematical description of the forest as a continuum or a system of layers with averaged dielectric permittivity, the second is the representation of a forest in the form of randomly located individual trees as discrete diffusers. The first approach gives adequate results in the VHF range, when the forest is sufficiently dense, and its structural elements are less than the length of the electromagnetic wave. The second is convenient to use at higher frequencies, when the individual elements of the tree, the diameter of the trunks, branches, and leaves are commensurate with the wavelength, as well as in a rare forest, with a large distance between the trees, when it is difficult to average out. The article compares the results of the calculation of the attenuation of the electromagnetic field using both approaches, gives the interpretation of the resulting physical mechanisms of radio wave propagation.