- Industry: Earth science
- Number of terms: 93452
- Number of blossaries: 0
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Founded in 1941, the American Congress on Surveying and Mapping (ACSM) is an international association representing the interests of professionals in surveying, mapping and communicating spatial data relating to the Earth's surface. Today, ACSM's members include more than 7,000 surveyors, ...
(1) A map projection trans-forming parallels of latitude into circles with radii which are the geometric averages of those of the stereographic and the azimuthal equal area map projections. The radius r of the circle representing a parallel of latitude φ is given by r = 2 κ R½ (tan¼ (π - 2φ) sin¼ (π - 2φ)), in which κ is the scale factor and R is the radius of the sphere. The meridians are represented by the radii of these concentric circles and have the same directions as the radii of the parent graticules. (2) A somewhat similar map projection, based on the harmonic average rather than on the geometric average of the radii, and with the scale changed to give the least total error for a map of given radius. This variant was introduced by A. E. Young in 1920.
Industry:Earth science
A darkened chamber or box into which light is admitted through a small hole, to form an image on the wall or side opposite the hole. The hole may or may not contain a lens. An example of the lensless type is the pinhole camera; an example of the type with lens is the ordinary box camera. The solar telescope, which projects an image of the Sun onto a screen, is also a camera obscura. The camera obscura should not be confused with the camera lucida; the former creates a real image, the latter a virtual image.
Industry:Earth science
A long, deep and narrow valley with steep sides and confined between very high and steep walls in a plateau or mountainous region. It often has a stream at the bottom. It is similar to but larger than a gorge.
Industry:Earth science
A circle having as its center a point whose location has been determined and as its radius the probable error of the location.
Industry:Earth science
A nautical chart intended for coastwise navigation inshore when a vessel's course may carry her inside outlying reefs and shoals. It is intended for use in entering or leaving bays and harbors of considerable size or for use in navigating large, inland waterways.
Industry:Earth science
Orienting and mechanically locking the rotational axis of a gyroscope to an internal reference-position.
Industry:Earth science
The person who marks the locations of the tape's ends in measuring distance with a graduated tape.
Industry:Earth science
An equity investment that represents ownership of a firm, which full participation in its success or failure. The firm's directors must approve dividend payments.
Industry:Earth science
The scale at which a map is compiled, as distinct from the expressed scale of the map.
Industry:Earth science
