Path Loss Modeling for Near-Ground VHF Radio-Wave Propagation Through Forests With Tree-Canopy Reflection Effect

This paper presents a new methodology to model the near- ground short-range propagation loss in forested areas at the VHF and the UHF band. The path loss modeling is performed by an integration of the foliage induced efiect and the efiect from the radio- wave re∞ection/re∞ections. The analysis shows that the re∞ection from the dense tree canopy is important for short-range propagation at the VHF band and therefore, cannot be ignored. When taking into consideration the contribution from the possible tree-canopy re∞ection, the modeled path loss is reduced by more than 15dB in the VHF band. A good agreement of the modeled path loss with the measured loss in tropical forested areas is achieved.