- 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, ...
The point of origin of an early leveling network used in Great Britain and now obsolete. It has been used in determining changes of sea level along the coast.
Industry:Earth science
A transit to which is fastened a micrometer for following the motion of a star through the field of view and determining the instant at which a star passes through a given vertical circle. The micrometer has one or more movable threads which lie in the focal plane of the telescope. The threads are moved in the direction of azimuth by a single screw with a graduated head. The star is followed by rotating the screw and recording an observation at each of the main graduations. Local sidereal time can be determined if the telescope is set up to move in the meridional plane or to determine latitude if set up to rotate in the plane of the prime vertical.
Industry:Earth science
An orbital element specifying the orientation of an orbit. It is a broken angle consisting of the angle, in the plane of the ecliptic, from the vernal equinox to the ascending node, plus the angle, in the plane of the orbit, from the ascending node to the pericenter.
Industry:Earth science
(1) A geometric element of surface, resulting from subdividing an image into identically-shaped figures such that each figure gives information about the location, intensity and perhaps color of the source, but no smaller subdivision gives more information. The concept of pixel (the term is a corruption of pictorial element) is valid only for images composed of discrete patches. It is not valid for continuous images. The term is not precisely equivalent to resolution even when resolution is expressed in terms of area, because resolution can be defined for images which are not composed of discrete patches. The size of a pixel is determined principally by the size of the smallest, individual, radiation-sensitive element in the device creating the image. For example, in the human eye, the pixel is the size of the region occupied, on the retina, by a cone. On a photograph, it is the size of the smallest clump of silver. (2) That geometric region, on the object, which corresponds to the smallest information-containing geometric element in the image
Industry:Earth science
(1) Those computational steps required to determine the location and orientation of a camera's coordinate system in the coordinate system used for object space. (2) Those computational steps required to determine tilt, direction of the principal line, flight height, preparation of templates at the scale used for rectification, distances and angles, and preparing aerial photographs for rectification. The resulting values are set on the circles and scales of a rectifier or transforming printer. (3) Adjustment of a rectifier by setting, on the rectifier's controls, the precise values needed for orientation; these values having been calculated beforehand.
Industry:Earth science
Sand and gravel deposited by a stream of melted ice in front of or on the margin of an active glacier.
Industry:Earth science
Transformation of one rectangle into another of different proportions.
Industry:Earth science
A survey in which the Earth's magnetic field or a portion thereof is measured using a magnetometer.
Industry:Earth science
