another term for zenithal projection
A map projection in which a globe, as of the Earth, is assumed to rest on a flat surface onto which its features are projected. An azimuthal projection produces a circular map with a chosen point—the point on the globe that is tangent to the flat surface—at its center. When the central point is either of Earth’s poles, parallels appear as concentric circles on the map and meridians as straight lines radiating from the center. Directions from the central point to any other point on the map are accurate, although distances and shapes in some azimuthal projections are distorted away from the center. Compare conic projection, cylindrical projection.
- Azimuthal equidistant projection
a projection in which the shortest distance between any point and a central point is a straight line, such a line representing a great circle through the central point. azimuthal equidistant projection (āz’ə-mŭth’əl) An azimuthal map projection designed so that a straight line from the central point on the map to any other point gives […]
Astronomy, Navigation. the arc of the horizon measured clockwise from the south point, in astronomy, or from the north point, in navigation, to the point where a vertical circle through a given heavenly body intersects the horizon. Surveying, Gunnery. the angle of horizontal deviation, measured clockwise, of a bearing from a standard direction, as from […]
- Azimuth circle
a device for measuring azimuths, consisting of a graduated ring equipped with a sighting vane on each side, which fits concentrically over a compass. Historical Examples An arc of the horizon intercepted between the azimuth circle of a celestial object and the magnetic meridian. The Sailor’s Word-Book William Henry Smyth The mean of all the […]
- Azimuth bar
a device used in measuring azimuths, consisting of a bar with a sighting vane at each end,pivoted at its center, and rotating in a horizontal plane around the center of a compass.