VHF Propagation Results Using Low Antenna Heights in Tropical Forests
Special technical rept. no. 46
STANFORD RESEARCH INST MENLO PARK CA
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op measurements previously reported are converted to radio system loss. Conversion from received voltage to system loss for a system using half- wave dipoles is also possible through relationships derived here, and an approximate formula is given for conversion to basic transmission loss. The use of horizontal polarization produces a much lower system loss than does the use of vertical polarization in the forest for the cases studied, with the exception of very low antanna heights. Tests made with a balloon-borne Xeledop elevated several hundred feet indicated the operational superiority of vertical dipoles over horizontal dipoles for balloon-elevated relays used in jungle terrain. The system loss for vertical polarization exceeded that obtained with horizontal polarization and optimum geometry, but optimum geometry for horizontal polarization was difficult to maintain.
- Radio Communications