Analysis of radiowave propagation in a four-layered anisotropic forest environment

Propagation of electromagnetic waves in forest environments is examined in which both the transmitting and receiving points are located in the trunk layer of a four-layered anisotropic forest model. This propagation model considers the forest as a horizontally stratified, anisotropic media of canopy and trunk, bounded by ground below and air above. The electromagnetic fields are obtained using dyadic Green´s functions in their eigenfunction expansion forms for an anisotropic four-layered geometry. Analytical results are found for the fields, which consist primarily of three wave modes: a direct wave, multiply reflected waves, and lateral waves. These field constituents are compared, and their domains of preponderance are calculated; it is found that the lateral wave plays a major role in communication at large distances. Radio losses for typical forest are calculated to illustrate numerical application of the forest model