Title :
VHF/UHF radiowave propagation through forests: modelling and experimental observations
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., George Washington Univ., Washington, DC, USA
fDate :
2/1/1992 12:00:00 AM
Abstract :
A forest-propagation model has been developed which includes the effects of trunks, branches, leaves and the ground. This model represents the forest as a planar, stratified, anisotropic, discrete, random medium, bounded above by air and below by ground. The mean field of the propagating wave has been obtained by recognising that the ensemble of discrete scatterers can be replaced by an equivalent continuous medium characterised by a linear dyadic permittivity. Fourier-transform techniques have been employed to generalise the model so that is accommodates arbitrarily modulated waveforms. Comparison of the model predictions with experimental data are presented for typical forest parameters. The paper also discusses predicted values of transmission loss as they relate to distance, antenna height, frequency, polarisation and biophysical forest parameters
Keywords :
radiowave propagation; 200 MHz to 2 GHz; Fourier-transform techniques; UHF; VHF; anisotropic medium; antenna height; arbitrarily modulated waveforms; biophysical forest parameters; branches; discrete random medium; discrete scatterers; equivalent continuous medium; forest-propagation model; frequency dependence; ground effects; leaves; linear dyadic permittivity; planar stratified medium; polarisation; radiowave propagation; transmission loss; trunks;
Journal_Title :
Microwaves, Antennas and Propagation, IEE Proceedings H
