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Line of sight (LoS) propagation from an antenna. Line-of-sight propagation is a characteristic of electromagnetic radiation or acoustic wave propagation which means waves can only travel in a direct visual path from the source to the receiver without obstacles. [1] Electromagnetic transmission includes light emissions traveling in a straight line.
VHF transmission range is a function of transmitter power, receiver sensitivity, and distance to the horizon, since VHF signals propagate under normal conditions as a near line-of-sight phenomenon. The distance to the radio horizon is slightly extended over the geometric line of sight to the horizon, as radio waves are weakly bent back toward ...
What do the line of sight equations have to do with VHF? I'll delete in the morning if no explanation comes up. MooCreature 03:56, 14 February 2006 (UTC) VHF range is line-of-sight, so the equations are directly relevant, giving the range available for a given antenna height. Do not delete. If anything, a word of explanation is all that is needed.
Millimeter waves propagate solely by line-of-sight paths. They are not refracted by the ionosphere nor do they travel along the Earth as ground waves as lower frequency radio waves do. [4] At typical power densities they are blocked by building walls and suffer significant attenuation passing through foliage.
The frequency of radio waves used by most radars, in the form of microwaves, travel in straight lines.This generally limits the detection range of radar systems to objects on their horizon (generally referred to as "line of sight" since the aircraft must be at least theoretically visible to a person at the location and elevation of the radar transmitter) due to the curvature of the Earth.
The ARC-231 Skyfire is a software-definable radio for military aircraft that provides two-way, multi-mode voice and data communications over a 30 to 512 MHz frequency range. It covers both line-of-sight Ultra High Frequency (UHF) and Very High Frequency (VHF) bands with AM , FM and SATCOM capabilities, [ 1 ] including Integrated Waveform (IW).
Predicted line of sight (PLOS) is a method of missile targeting. In PLOS, the operator tracks the target with the missile launcher's onboard sights for a short period of time (3-5 seconds). Software on the launcher extrapolates from the data gathered, producing a prediction of the route required to intercept the moving target.
This signal is sent to the missile, often using thin metal wires or a radio link, which causes it to steer back toward the center of the line-of-sight. Common examples of these weapons include the BGM-71 TOW wire-guided anti-tank guided missile (ATGM) and the Rapier radio-command surface-to-air missile (SAM).