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Horizontal coordinate system
Type of celestial coordinate system / From Wikipedia, the free encyclopedia
Not to be confused with Horizontal position representation.
The horizontal coordinate system is a celestial coordinate system that uses the observer's local horizon as the fundamental plane to define two angles of a spherical coordinate system: altitude and azimuth. Therefore, the horizontal coordinate system is sometimes called the az/el system,[1] the alt/az system, or the alt-azimuth system, among others. In an altazimuth mount of a telescope, the instrument's two axes follow altitude and azimuth.[2]
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