- 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, ...
The square of the average of the square root of the absolute value of the true error.
Industry:Earth science
An error arising from variations in natural phenomena such as geomagnetism, gravity, humidity, refraction, temperature or wind.
Industry:Earth science
A topographic feature such as sand, swamp or vegetation, which extends over a considerable area. It is represented on a published map by a solid or patterned color, by a prepared symbol, or by a delimiting line.
Industry:Earth science
A personal error committed by improperly orienting a diapositive in the printer or, later, in the projector of a stereoscopic plotting instrument, or both, and resulting in unequal displacement of the principal points in the instrument and an error in the vertical distances.
Industry:Earth science
The ratio of the difference between an approximate value and the correct value, to the correct value.
Industry:Earth science
The amount by which the sum of the three angles of a spherical triangle exceeds 180<sup>o</sup>. The amount of spherical excess depends on the radius of curvature and on the area of the triangle, and is about 1" for each 195.8 square kilometers on a rotational ellipsoid representing the Earth. In geodesy, in the computation of triangles, the difference between spherical angles and spheroidal angles is generally neglected; spherical angles are used and Legendre's Theorem is applied to the distribution of the spherical excess. That is, approximately one third of the spherical excess of a given spherical triangle is subtracted for each angle of the triangle.
Industry:Earth science
The error committed by assuming that one member of or sample from a statistical population is a valid representative of that population. In particular, in the analysis of data on gravity, the error committed by using the value of gravity at one or more points in a region instead of using the average value of gravity in the region. The term is also used in this way with respect to gravity anomalies.
Industry:Earth science
