In this paper, some existing radio wave propagation loss models for the forested environments are briefly reviewed. As
a continuation of the research progress on radio propagation characteristics through forested channels, the experimental measurements carried out on the radio wave propagation loss at VHF (92.1MHz as a case study) through long (~64km) forested communication channels are reported. The experimental measurement results obtained are compared with some existing propagation loss models: Free Space Attenuation (FSA), Ground Reflection (GR) and Canopy Ground Reflection (CGR) models, and integration of foliage-induced effect and reflection effect models: CGR plus ITU-R or SUM(CGR, ITU-R) and CGR plus Weissberger or SUM(CGR, Weissberger). Using the method of least square fit to the experimental measured data, CGR model gives the best fit for the radio wave propagation loss at VHF (92.1MHz) through long tropical forested channel.
This paper is organized as follows: Section I gives the introduction of the behaviour of the propagation of radio wave through forest channels. Section II briefly review some related work on the radio wave propagation in the forest. Section III explains the experimental method used to carry out the study. Section IV explains the results obtained and gives the implications. The last section V concludes the paper and followed by references and author biography.