- Industry: 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, ...
A compass depending for its indications on the current generated in a coil rotating in the Earth's magnetic field.
Industry:Earth science
One of the 32 equal divisions into which the circle surrounding the needle of a compass is divided. Each division is 11. 25<sup>o</sup> and may be further subdivided into quarters called quarter point.
Industry:Earth science
One of the two points on which a standard bar rests when in use if the distance between lines engraved on the ends of the neutral fiber is to be a maximum. The distance between symmetrically placed supports is approximately 0. 5994 times the length of the bar. The neutral fiber is that surface, in the bar, which has the same length before and after the bar is placed on the supports. Note that although the length between marks remains the same, the distance diminishes because the bar is distorted by its own weight when placed on the supports.
Industry:Earth science
That circle, in the plane, which passes through three known points. The accuracy with which a fourth point in the plane can be located depends on the location of that point with respect to the critical circle. If it lies on the circle, its location cannot be found by resection.
Industry:Earth science
(1) The intersection of a sphere with a plane not passing through the center of the sphere. The formulae of spherical trigonometry generally do not apply to arcs of small circles but only to arcs of great circles. Circles of latitude are small circles. (2) The intersection of a sphere representing the Earth with a plane which does not pass through the center of the sphere. Some definitions specify a circle on the Earth; such definitions are empty.
Industry:Earth science
One of a set of points selected, in an oblique aerial photograph, in the vicinity of each tie point and distant point, for the purpose of checking the identification of those points.
Industry:Earth science
A small scale (1:3,000,000 or less) aeronautical chart designed for navigation on long flights and relying principally on dead reckoning and celestial navigation.
Industry:Earth science
An inversor embodying a cam which follows a specially-shaped track and used in rectifiers and similar instruments to keep the photographic negative, the lens system's perspective center, and the easel (onto which the photographic image is projected) in proper relationship when the distances of projection are changed.
Industry:Earth science
