enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Very high frequency - Wikipedia

    en.wikipedia.org/wiki/Very_high_frequency

    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 ...

  3. Line-of-sight propagation - Wikipedia

    en.wikipedia.org/wiki/Line-of-sight_propagation

    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.

  4. Radio propagation - Wikipedia

    en.wikipedia.org/wiki/Radio_propagation

    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]

  5. VHF omnidirectional range - Wikipedia

    en.wikipedia.org/wiki/VHF_omnidirectional_range

    VOR stations, being VHF, operate on "line of sight". This means that if, on a perfectly clear day, you cannot see the transmitter from the receiver antenna, or vice versa, the signal will be either imperceptible or unusable. This limits VOR (and DME) range to the horizon—or closer if mountains intervene. Although the modern solid state ...

  6. Link budget - Wikipedia

    en.wikipedia.org/wiki/Link_budget

    Older buildings may have even greater internal losses than new buildings due to materials and line of sight issues. Experience has shown that line-of-sight propagation holds only for about the first 3 meters. Beyond 3 meters propagation losses indoors can increase at up to 30 dB per 30 meters in dense office environments.

  7. Free-space path loss - Wikipedia

    en.wikipedia.org/wiki/Free-space_path_loss

    In telecommunications, the free-space path loss (FSPL) (also known as free-space loss, FSL) is the attenuation of radio energy between the feedpoints of two antennas that results from the combination of the receiving antenna's capture area plus the obstacle-free, line-of-sight (LoS) path through free space (usually air). [1]

  8. Extremely high frequency - Wikipedia

    en.wikipedia.org/wiki/Extremely_high_frequency

    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.

  9. Line of sight - Wikipedia

    en.wikipedia.org/wiki/Line_of_sight

    Line-of-sight propagation, electro-magnetic waves travelling in a straight line Non-line-of-sight propagation; Line-of-sight fire, shooting directly at a visible target on a relatively flat trajectory; Line-of-sight velocity, an object's speed straight towards or away from an observer; Line-of-sight double star, one in which two stars are only ...