- 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, ...
A variety of invar, composed of approximately 34% nickel, 57% iron, 4% chromium and 2 % tungsten. The springs in some spring type gravimeters are of elinvar.
Industry:Earth science
(1) The gravitational potential energy at a point P is the amount of work done by (or from) a conservative field in carrying a unit mass to P from infinity. (2) The difference ΔW in gravitational potential energy between points P and Q is the amount of work done, by a conservative field, in carrying a unit mass from P to Q.
Industry:Earth science
A mechanical or electromechanical device on wheels which measures slope and distance, and automatically and continuously integrates their product into difference of elevation. The version developed by the U. S. Geological Survey is called a Ground Elevation Meter.
Industry:Earth science
An elevation which has been obtained either from tidal observations or from a previous adjustment of leveling, and which is held at its adopted value in any subsequent adjustment.
Industry:Earth science
A map or chart published for temporary use only, with the provision that it will be superseded later.
Industry:Earth science
A date and a time which specify the reference system to which celestial coordinates are referred. Coordinates in star catalogs are commonly referred to the mean equinox and equator of the beginning of a Besselian year.
Industry:Earth science
An entry of irrigable and agricultural public lands under the act of March 3, 1877, as amended, which the entryman reclaims, irrigates, and cultivates in part and for which he pays a certain amount.
Industry:Earth science
(1) The act of endowing, or bestowing a dower, fund or permanent provision for support. (2) That which is bestowed or settled on a person or an institution.
Industry:Earth science
The ellipse in which a plane through the center of an ellipsoid cuts the ellipsoid. When the ellipsoid is rotationally symmetrical, the great ellipse may be a circle; when the ellipsoid is a sphere, the great ellipse is a great circle.
Industry:Earth science
Distance - measuring equipment operating at 2 MHz and involving the measurement of the time it takes radio pulses to travel between the vessel carrying the indicator and each of two stations on land. Abbreviated as E. P. I. or written as an acronym EPI. It has been used primarily in hydrographic sur-veying. Distances of over 800 km can be measured. The accuracy is between 60 and 500 meters.
Industry:Earth science
