Search results
Results From The WOW.Com Content Network
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.
The two-rays ground-reflection model is a multipath radio propagation model which predicts the path losses between a transmitting antenna and a receiving antenna when they are in line of sight (LOS). Generally, the two antenna each have different height. The received signal having two components, the LOS component and the reflection component ...
Line-of-sight fire, shooting directly at a visible target on a relatively flat trajectory. The target is in the line of sight of the sighting device and the rifleman's rule applies. Line-of-sight range; Line-of-sight (missile), the straight line between the missile and the target; Radar horizon
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.
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. [1]: 26‑1 As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. [2]
Although intuitively, clear line-of-sight between transmitter and receiver may seem to be all that is required for a strong antenna system, but because of the complex nature of radio waves, obstructions within the first Fresnel zone can cause significant weakness, even if those obstructions are not blocking the apparent line-of-sight signal path.
In the development of radio, ground waves were used extensively. Early commercial and professional radio services relied exclusively on long wave, low frequencies and ground-wave propagation. To prevent interference with these services, amateur and experimental transmitters were restricted to the high frequencies (HF), felt to be useless since ...
A description of the method was published by the U.S. government under the title "Prediction of Tropospheric Radio Transmission Loss Over Irregular Terrain: A Computer Method - 1968", A. G. Longley and P. L. Rice, NTIA Tech. Rep. ERL 79-ITS 67, U.S. Government Printing Office, Washington, DC, July 1968.