- 行业: Earth science
- Number of terms: 93452
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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, ...
One of three rotational ellipsoids calculated by Clarke in 1858, of which the following two are particularly important (the factor 0. 30480047 was used to convert from feet to meters). (1) A rotational ellipsoid having the dimensions<br>
Industry:Earth science
A survey made in the vicinity of Cape Canaveral, Florida, to determine the geodetic coordinates of nine ballistic cameras there. In the adjustment, the horizontal geodetic coordinates of two points were held fixed to their values on North American Datum 1927. The points and their coordinates are<br>
Industry:Earth science
A method devised by Boltz for solving the normal equations occurring in the adjustment of a triangulation network; it allows a large set of equations to be solved in one straight operation by the method of least squares without biasing the solution towards any particular unknown. Initially, the normal equations were solved using the Gaussian method of successive elimination. This method, however, causes the last determined value to contain larger errors than the first determined value. Boltz's method treats all unknowns equally and is particularly suitable for solving large systems of equations.
Industry:Earth science
(1) A chart of polar regions. (2) A chart drawn using a polar map projection. The map projections most used for polar charts are the azimuthal equidistant, the gnomonic, the modified Lambert conformal, the stereo-graphic, and the transverse Mercator.
Industry:Earth science
(1) A small diagram, on the face of a map, showing quantitative information. (2) An abstracted and simplified map the base of which is not true to scale.
Industry:Earth science
(1) A multicolored print made by coating a sheet with sensitizer and making consecutive exposures through the scribed sheet. Each color requires a separate coating, which is applied over the previous color print to form the composite, multicolored proof. (2) A printed, colored picture which is made specifically to let the user check that all elements of the picture are in the correct positions and that the colors register. Color proofs come in two forms - pre-press proofs and press proofs.
Industry:Earth science
A graphical representation of the vertical errors in the aerotriangulation of a strip of photographs. The x-coordinates of the vertical control points, referred to the initial nadir point as origin, are plotted along the axis of abscissas and the differences between the known elevations of the control points and their elevations as determined by aerotriangulation are plotted along the axis of ordinates. The Bz curve is a smooth curve drawn through the plotted points. The elevation of any pass point in the strip is adjusted by the amount of the ordinate of the Bz curve for the corresponding x-coordinate of the point.
Industry:Earth science
(1) A steep-sided, broad-floored valley with V-shaped cross-section cutting across the continental shelf or continental slope and resembling a river-cut, unglaciated canyon on land. (2) A small gully that cuts the submerged slope of a great delta. Such a gully usually ex-tends no deeper than 70 meters over the continental slope.
Industry:Earth science
