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 nearground 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 effect and the effect from the radiowave reflection/reflections. The analysis shows that the reflection 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 reflection, the modeled path loss is reduced by more than 15 dB in the VHF band. A good agreement of the modeled path loss with the measured loss in tropical forested areas is achieved.