- 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 force needed to give a mass of 1 kilogram an acceleration of 1 meter per second<sup>2</sup>. This is a derived unit in the SI. It is equal to 105 dynes.
Industry:Earth science
An instrument for measuring angles from the true center of perspective to points on a photograph.
Industry:Earth science
(1) The time taken by a satellite to complete one revolution about its primary, as referred to a fixed star. (2) The time required for a satellite of the Earth to make one complete revolution about the Earth, as referred to the same geocentric right-ascension.
Industry:Earth science
The length of time required for an orbiting body to move from one node in its orbit back to the same node.
Industry:Earth science
Able to be navigated by a vessel. The question of whether a stream or body of water is navigable is a question of fact with respect to the character of the stream or lake in its natural and ordinary condition as it was at the date of Statehood. At such time, the channel should have been a passage for commerce in the customary modes of trade and travel on water. Legal navigability includes the navigability of all coastal waters and tidal rivers, bays, bayous, lakes and their connecting tidal passages.
Industry:Earth science
When used with such terms as low water or high water, the term is considered, in law, to be equivalent to average.
Industry:Earth science
The numerical statement of the limits in Peirce's rule for rejecting observations. It is preferred to Chauvenet's criterion when more than one unknown is involved.
Industry:Earth science
(1) The angle subtended at the Sun by a line from the center of the Earth to an observer, on the equator, who has the Sun on his horizon. Solar parallax is the basis for the determination of the astronomical unit (the length of the semi-major axis of the Earth's orbit), and is often used, in astronomical calculations, instead of the astronomical unit for expressing distances to stars. The solar parallax is 8.794 148". (2) The quantity 8.794 148" adopted in 1977 by the International Astronomical Union as a standard value for the solar parallax.
Industry:Earth science
(1) The work required to raise a unit mass from the geoid to a given point. At all points on a given level surface, the dynamic number is the same and it is not very different from the height (in the same system of units) of any point on the surface. (2) The work required to raise a mass of 1 kilogram against the force of gravity from sea level to the level surface passing through the point, the work being measured in standard kilogram-meters at sea level in latitude 45<sup>o</sup>. (In the English system, dynamic number is expressed in pounds and foot-pounds.) Although the definition specifies sea level, geoid is usually understood. Although dynamic height and dynamic number are not defined exactly the same way, it is possible that the users intended the same concept. This is not certain, however, and it is best to adhere to the names belonging to the definitions given.
Industry:Earth science
