- Semi–great circles produced by projecting the earth’s meridian onto the celestial sphere. Each earth’s meridian has its corresponding celestial meridian. The celestial meridian of any place on the earth is the great circle of the celestial sphere that passes through the celestial poles, zenith, and nadir and intersects the horizon exactly north and south. As the celestial sphere and the stars rotate, the celestial meridian remains fixed. Astronomical bodies change their celestial meridians continually with time.
Aviation dictionary. 2014.
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celestial meridian — noun : a great circle of the celestial sphere passing through the celestial poles and the zenith … Useful english dictionary
meridian — [mə rid′ē ən] adj. [OFr meridien < L meridianus, of noon, southern < meridies, noon, the south < older medidies < medius,MID1 + dies, day: see DEITY] 1. of or at noon 2. of or passing through the highest point in the daily course of… … English World dictionary
meridian — Synonyms and related words: Antarctic Zone, Arctic Circle, Arctic Zone, Frigid Zones, Lambert conformal projection, Mercator projection, Miller projection, Torrid Zone, Tropic of Cancer, Tropic of Capricorn, Variable Zones, acmatic, acme,… … Moby Thesaurus
meridian angle — noun : the angle between the upper branch of the celestial meridian of an observer and the hour circle of a celestial object measured either westward or eastward from zero to 180 degrees compare hour angle * * * Astron. the angle, measured… … Useful english dictionary
meridian angle — Astron. the angle, measured eastward or westward through 180°, between the celestial meridian of an observer and the hour circle of a celestial body. Cf. hour angle. * * * … Universalium
meridian altitude — The altitude of a celestial body when the celestial meridian of the observer is either 000° or 180° … Aviation dictionary
meridian passage — The time at which a heavenly body crosses the observer’s celestial meridian … Aviation dictionary
Celestial meridiator — is a vertical imaginary line that goes over the celestial poles and crosses (perpendicular to) the celestial equator. There are two celestial meridiators on the celestial sphere: Equinox meridiator and Solstice meridiator.NameThe meridiators are… … Wikipedia
Celestial navigation — Celestial navigation, also known as astronavigation, is a position fixing technique that was devised to help sailors cross the featureless oceans without having to rely on dead reckoning to enable them to strike land. Celestial navigation uses… … Wikipedia
Celestial sphere — [ celestial equator.] In astronomy and navigation, the celestial sphere is an imaginary rotating sphere of gigantic radius , concentric and coaxial with the Earth. All objects in the sky can be thought of as lying upon the sphere. Projected from… … Wikipedia