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TV and FM DX — TV DX and FM DX is the active search for distant radio or television stations received during unusual atmospheric conditions. The term DX is an old telegraphic term meaning long distance. VHF/UHF television and radio signals are normally limited… … Wikipedia
ionosphere and magnetosphere — ▪ atmospheric science Introduction regions of Earth s (Earth) atmosphere in which the number of electrically charged particles ions (ion) and electrons (electron) are large enough to affect the propagation of radio waves (electromagnetic… … Universalium
Radio propagation — is a term used to explain how radio waves behave when they are transmitted, or are propagated from one point on the Earth to another. [ H. P. Westman et al, (ed), Reference Data for Radio Engineers, Fifth Edition , 1968, Howard W. Sams and Co.,… … Wikipedia
Optical phenomenon — An optical phenomenon is any observable event that results from the interaction of light and matter. See also list of optical topics and optics. A mirage is an example of an optical phenomenon. Common optical phenomena are often due to the… … Wikipedia
Antarctica — /ant ahrk ti keuh, ahr ti /, n. the continent surrounding the South Pole: almost entirely covered by an ice sheet. ab. 5,000,000 sq. mi. (12,950,000 sq. km). Also called Antarctic Continent. * * * Antarctica Introduction Antarctica Background:… … Universalium

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