Accession Number : ADA111719

Title :   Investigation and Development of VHF Ground-Air Propagation Computer Modeling Including the Attenuating Effects of Forested Areas for Within-Line-of-Sight Propagation Paths.

Descriptive Note : Final rept.,


Personal Author(s) : Chamberlin,Kent A

PDF Url : ADA111719

Report Date : Mar 1981

Pagination or Media Count : 183

Abstract : An investigation into short-distance (5-100 nm), air-ground, VHF propagation computer models is presented. An evaluation of existing propagation models is afforded by measured signal strength data, collected for this study, obtained for a variety of propagation paths; this evaluation shows existing models to be deficient due to their incapability to calculate attenuation caused by trees for within-line-of-sight propagation paths. The theory behind, and the development of, a computer model that does successfully account for tree attenuation is discussed and documented. A complete description of signal strength data collection is given detailing measurement equipment, site conditions, and data reduction. (Author)

Descriptors :   *Radio transmission, *Computerized simulation, Intensity, Radio signals, Line of sight, Very high frequency, Short range(Distance), Method of moments, Air to surface, Polarization, Radiation attenuation, Vegetation, Trees, Subroutines, Forests

Subject Categories : Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE