Matches in DBpedia 2015-10 for { <http://dbpedia.org/resource/Radio_propagation> ?p ?o }
- Radio_propagation abstract "Radio propagation is the behavior of radio waves when they are transmitted, or propagated from one point on the Earth to another, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering.Radio propagation is affected by the daily changes of water vapor in the troposphere and ionization in the upper atmosphere, due to the Sun. Understanding the effects of varying conditions on radio propagation has many practical applications, from choosing frequencies for international shortwave broadcasters, to designing reliable mobile telephone systems, to radio navigation, to operation of radar systems.Radio propagation is also affected by several other factors determined by its path from point to point. This path can be a direct line of sight path or an over-the-horizon path aided by refraction in the ionosphere, which is a region between approximately 60 and 600 km. Factors influencing ionospheric radio signal propagation can include sporadic-E, spread-F, solar flares, geomagnetic storms, ionospheric layer tilts, and solar proton events.Radio waves at different frequencies propagate in different ways. At extremely low frequencies (ELF) and very low frequencies the wavelength is much larger than the separation between the earth's surface and the D layer of the ionosphere, so electromagnetic waves may propagate in this region as a waveguide. Indeed, for frequencies below 20 kHz, the wave propagates as a single waveguide mode with a horizontal magnetic field and vertical electric field. The interaction of radio waves with the ionized regions of the atmosphere makes radio propagation more complex to predict and analyze than in free space. Ionospheric radio propagation has a strong connection to space weather. A sudden ionospheric disturbance or shortwave fadeout is observed when the x-rays associated with a solar flare ionize the ionospheric D-region. Enhanced ionization in that region increases the absorption of radio signals passing through it. During the strongest solar x-ray flares, complete absorption of virtually all ionospherically propagated radio signals in the sunlit hemisphere can occur. These solar flares can disrupt HF radio propagation and affect GPS accuracy.Since radio propagation is not fully predictable, such services as emergency locator transmitters, in-flight communication with ocean-crossing aircraft, and some television broadcasting have been moved to communications satellites. A satellite link, though expensive, can offer highly predictable and stable line of sight coverage of a given area.".
- Radio_propagation wikiPageExternalLink propagation.html.
- Radio_propagation wikiPageExternalLink propag.html.
- Radio_propagation wikiPageExternalLink ace-hf-demystified.html.
- Radio_propagation wikiPageExternalLink ace-hf-noise.html.
- Radio_propagation wikiPageExternalLink ace-hf-reciprocal.html.
- Radio_propagation wikiPageExternalLink propagation.htm.
- Radio_propagation wikiPageExternalLink msg00075.html.
- Radio_propagation wikiPageExternalLink solar.
- Radio_propagation wikiPageExternalLink data.php.
- Radio_propagation wikiPageExternalLink sunspotwatch.com.
- Radio_propagation wikiPageExternalLink wap.hfradio.org.
- Radio_propagation wikiPageExternalLink propagation-of-rf-signals.
- Radio_propagation wikiPageExternalLink qsl-hf-tutorial-nm7m.htm.
- Radio_propagation wikiPageExternalLink propagation.
- Radio_propagation wikiPageExternalLink solar.html.
- Radio_propagation wikiPageExternalLink moflof.
- Radio_propagation wikiPageExternalLink HF_Systems.
- Radio_propagation wikiPageExternalLink Propfire.htm.
- Radio_propagation wikiPageExternalLink prop.
- Radio_propagation wikiPageExternalLink radio-propagation-overview-tutorial.php.
- Radio_propagation wikiPageExternalLink www.solarcycle24.org.
- Radio_propagation wikiPageExternalLink www.spacew.com.
- Radio_propagation wikiPageExternalLink nz4o5.htm.
- Radio_propagation wikiPageID "271195".
- Radio_propagation wikiPageLength "33187".
- Radio_propagation wikiPageOutDegree "226".
- Radio_propagation wikiPageRevisionID "682398381".
- Radio_propagation wikiPageWikiLink 10.7cm_radiation.
- Radio_propagation wikiPageWikiLink AM_broadcasting.
- Radio_propagation wikiPageWikiLink ARRL.
- Radio_propagation wikiPageWikiLink Absorption_(electromagnetic_radiation).
- Radio_propagation wikiPageWikiLink Aircraft.
- Radio_propagation wikiPageWikiLink Amateur_radio.
- Radio_propagation wikiPageWikiLink American_Radio_Relay_League.
- Radio_propagation wikiPageWikiLink Astronomy.
- Radio_propagation wikiPageWikiLink Atmosphere.
- Radio_propagation wikiPageWikiLink Atmosphere_of_Earth.
- Radio_propagation wikiPageWikiLink Attenuation.
- Radio_propagation wikiPageWikiLink Aurora.
- Radio_propagation wikiPageWikiLink Aurora_(astronomy).
- Radio_propagation wikiPageWikiLink Backscatter.
- Radio_propagation wikiPageWikiLink Beam_tilt.
- Radio_propagation wikiPageWikiLink Body_of_water.
- Radio_propagation wikiPageWikiLink Border.
- Radio_propagation wikiPageWikiLink Broadcast_license.
- Radio_propagation wikiPageWikiLink Broadcasting.
- Radio_propagation wikiPageWikiLink Caribbean.
- Radio_propagation wikiPageWikiLink Category:Radio_frequency_propagation.
- Radio_propagation wikiPageWikiLink Cell_phones.
- Radio_propagation wikiPageWikiLink Cellular_network.
- Radio_propagation wikiPageWikiLink Cellular_telephony.
- Radio_propagation wikiPageWikiLink Chirp_Transmitter.
- Radio_propagation wikiPageWikiLink Chirp_transmitter.
- Radio_propagation wikiPageWikiLink Clear-channel_station.
- Radio_propagation wikiPageWikiLink Cloud_cover.
- Radio_propagation wikiPageWikiLink Communications_satellite.
- Radio_propagation wikiPageWikiLink Coronal_hole.
- Radio_propagation wikiPageWikiLink Coronal_holes.
- Radio_propagation wikiPageWikiLink Coronal_mass_ejection.
- Radio_propagation wikiPageWikiLink D_layer.
- Radio_propagation wikiPageWikiLink Detroit.
- Radio_propagation wikiPageWikiLink Detroit_River.
- Radio_propagation wikiPageWikiLink Dew.
- Radio_propagation wikiPageWikiLink Diffraction.
- Radio_propagation wikiPageWikiLink Directional_antenna.
- Radio_propagation wikiPageWikiLink Distress_radiobeacon.
- Radio_propagation wikiPageWikiLink Diurnal_cycle.
- Radio_propagation wikiPageWikiLink Diversity_scheme.
- Radio_propagation wikiPageWikiLink Doctor_of_Medicine.
- Radio_propagation wikiPageWikiLink Doctor_of_Philosophy.
- Radio_propagation wikiPageWikiLink Dominican_Republic.
- Radio_propagation wikiPageWikiLink E_layer.
- Radio_propagation wikiPageWikiLink Earth.
- Radio_propagation wikiPageWikiLink Earth-ionosphere_waveguide.
- Radio_propagation wikiPageWikiLink Earth_bulge.
- Radio_propagation wikiPageWikiLink Earths_atmosphere.
- Radio_propagation wikiPageWikiLink Earth–ionosphere_waveguide.
- Radio_propagation wikiPageWikiLink Effective_radiated_power.
- Radio_propagation wikiPageWikiLink Electromagnetic_radiation.
- Radio_propagation wikiPageWikiLink Electromagnetic_wave.
- Radio_propagation wikiPageWikiLink Extremely_high_frequency.
- Radio_propagation wikiPageWikiLink Extremely_low_frequency.
- Radio_propagation wikiPageWikiLink F2_propagation.
- Radio_propagation wikiPageWikiLink FM_broadcasting.
- Radio_propagation wikiPageWikiLink F_layer.
- Radio_propagation wikiPageWikiLink F_region.
- Radio_propagation wikiPageWikiLink Fading.
- Radio_propagation wikiPageWikiLink Fog.
- Radio_propagation wikiPageWikiLink Free_space.
- Radio_propagation wikiPageWikiLink Frequency_reuse.
- Radio_propagation wikiPageWikiLink Fresnel_zone.
- Radio_propagation wikiPageWikiLink Frost.
- Radio_propagation wikiPageWikiLink Fundamental_frequency.
- Radio_propagation wikiPageWikiLink GPS.
- Radio_propagation wikiPageWikiLink GPS_meteorology.
- Radio_propagation wikiPageWikiLink Geomagnetic_storm.
- Radio_propagation wikiPageWikiLink Gigahertz.
- Radio_propagation wikiPageWikiLink Global_Positioning_System.
- Radio_propagation wikiPageWikiLink Great_Lakes.