- Branche: Earth science
- Number of terms: 93452
- Number of blossaries: 0
- Company Profile:
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 copy in three dimensions of an object, usually on a smaller scale but occasionally on a larger scale. Models are used extensively in engineering; tests are made on the model instead of on the original. The results of such tests are then made to apply to the original by dimensional analogy. Models are also used in other sciences such as physical oceanography and crustal physics. They are little used in surveying or geodesy except as representations of terrain and usually in regions of small area. (2) In particular, in photogrammetry, the visual or optical image (called a stereoscopic model) produced by combining the images from two photographs of the same object from different angles or by creating a hologram. (3) A simplified, theoretical, not necessarily mathematical representation of a real thing or event and acting like the original in situations of interest. (4) A mathematical function or representation.
Industry:Earth science
An exposure (of photographic film) for 1 second at a distance of 1 meter to a light-source of 1 candela.
Industry:Earth science
(1) The accuracy with which details on a map are located with respect to each other, as compared to their correct relative locations, i.e., the relative locations of the corresponding details on the ground. (2) The accuracy with which details on a map are located with respect to the graticule on the map, regardless of any error in the graticule or the datum defining the graticule.
Industry:Earth science
A survey to determine the locations and dimensions of underground passages of a mine and of the natural and artificial features, underground and on the surface, relating to the mine. The data include both horizontal and vertical coordinates, lengths, and directions and inclinations of tunnels; topographic and geological characteristics of the particular locality; ownership of the land and the mine; etc.
Industry:Earth science
The value obtained by dividing the misclosure of a traverse by the length of the traverse. Relative misclosure is commonly expressed as a fraction whose numerator is 1, e.g., 1/1320.
Industry:Earth science
A tract of land frequently covered by shallow water and growths of water weed.
Industry:Earth science
A map projection in which the particular scale in a direction radial from the point of zero distortion or perpendicular to the line of zero distortion remains constant throughout the map but is not equal to the principal scale. If such a map projection is to be useful, the departure of this particular scale from unity should be small.
Industry:Earth science
The amount by which two values of the azimuth of a line, derived by different surveys or along different routes, differ. Usually, one value is derived by computations using the measurements made during the survey (traverse, triangulation, or trilateration); the other is an adjusted or fixed value determined by an earlier or more precise survey or by independent, astronomical observations.
Industry:Earth science
