- 行业: 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, ...
That property of a transformation from one surface to another surface which ensures that the angle between any two curves on one surface is reproduced in magnitude and sense between the corresponding curves on the other surface. This property is equivalent to the condition that the coefficients of the first fundamental form on one surface be proportional to the corresponding coefficients of the form for the other surface, both surfaces having the same coordinate system. Hence, isometric mappings are also conformal.
Industry:Earth science
Photogrammetric control available for absolute orientation of the first pair of photographs along a line of flight covering ground for which control is to be extended.
Industry:Earth science
A coordinate of a point in a barycentric coordinate system.
Industry:Earth science
A correction applied to a measured horizontal angle to eliminate any error that may have been caused by the horizontal axis of the instrument not having been exactly horizontal. If the horizontal axis of the instrument is not exactly horizontal, the line of collimation will not cut the horizon at a point directly underneath (or above) an observed point, that is a plane described by the line of collimation when the telescope is rotated about the horizontal axis will not be vertical. The inclination of the horizontal axis may involve one or both of two conditions: the horizontal and vertical axes of the instrument may fail to meet exactly at a right angle, and the vertical axis may deviate from the direction defined by the plumb line. So, determining the correction requires that both the inclination of the axis and the angular elevation of the observed point be known.
Industry:Earth science
The data associated with a set of control stations, giving the locations of these stations and used as the basis for detailed surveys. Basic control is not changed by the detailed surveys nor by their subsequent adjustment. It may contain horizontal coordinates, vertical coordinates, or both. The basic control for the Topographic Map of the United States consists of the data from first order and second order triangulation and traverse, and from first order and second-order leveling.
Industry:Earth science
That part of the deflection of the vertical which is caused by the gravitational pull exerted by topographic masses. Topographic deflection of the vertical is not the same as deflection of the vertical or station error but is the theoretical effect produced by the resultant gravitational pull of the unevenly distributed, topographic masses around the station, no allowance being made for isostatic compensation.
Industry:Earth science
One of the two angles, celestial longitude and celestial latitude, in an ecliptic coordinate system.
Industry:Earth science
One of a pair of marks placed on opposite edges of a chart to indicate the location of a line of longitude or of latitude with respect to a particular datum.
Industry:Earth science
A physical object close to a corner and which is referred to in describing the location of the corner. Examples are bearing trees, mounds, pits, ledges, rocks and other natural features to which distances or directions, or both, from the corner or monument are known. Corner accessories are considered part of the monument of the corner. As a witness to the corner, it carries the same weight, legally, when the latter is found to be missing or destroyed.
Industry:Earth science
A contract to sell real estate, payments being made in installments; upon payment of the last installment, the deed is delivered to the purchaser.
Industry:Earth science
