Investigation of Propagation in Foliage Using Simulation Techniques

摘要

In a foliage environment, radio wave propagation is subjected to fading on both large-scales and small-scales that impairs the quality and reliability of data link transmission. This has implications for many military operations. One example is the effects of foliage on the performance of communications links and unmanned aerial vehicle (UAV) radio links when ground forces are operating in foliage environments. The purpose of this research is to evaluate some simple models for the propagation of radio waves in foliage using an electromagnetic field simulation application. The three dimensional (3D) electromagnetic field simulation application, CST Studio Suite, was used in the modeling and simulation process. Specifically, the CST Microwave Studio module was used to model the forest using dielectric blocks. Various combinations of forest dimensions, material dielectric parameters, and antenna placements were simulated to obtain propagation models of radio waves in foliage environments. Using the simulation models, we examined the coverage diagram for a transmitter antenna immersed in foliage. The results show that the proposed models provide a rough approximation to radio wave propagation in an actual rainforest environment. The path loss in foliage is affected by the forest's electrical characteristics, the height of the transmitter, and the height of the receiver. In addition, the simulation models were compared to three empirical models to determine their accuracy. The empirical models were Tewari's model, the Jansky and Bailey model, and the LITU-R model.