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horizon
- Definição1
- (1) In general, the apparent or visible junction of the earth and the sky, as seen from any specific position. Also called a visible or local horizon. (2) When an apparent boundary is modified by refraction, terrain, or other factors, it is called as apparent horizon. (3) A small circle on the celestial sphere, the plane of which passes through the observer's eye and is parallel to the observer's rational horizon, is called a sensible horizon. (4) A path followed by a radar beam when it is tangential to earth is a radar horizon. (5) The locus of the point at which direct rays from a terrestrial radio transmitter become tangential to earth is a radio horizon. (6) A line resembling the visible horizon but above or below it is called a false horizon. (7) An artificial horizon is a gyroscopic instrument for indicating the attitude of an aircraft with respect to the horizontal.
- Fonte1
- KUMAR, Bharat (ed.). An illustrated dictionary of aviation. New York: McGraw-Hill, c2005. 752 p.
- Subárea1
- Air Navigation
- Related Term
- artificial horizon
- Português
- horizonte