- 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, ...
A map showing the size, density, kind and value of trees on a given region.
Industry:Earth science
A method of triangulation in which observations of a flashing light at very high altitudes are made simultaneously from a number of stations of known and unknown location. The flashes occur at timed instances and can be distinguished by those times, so that observations made on the same flash are simultaneous.
Industry:Earth science
A discontinuity supposedly lying between the Conrad and Mohorovicic discontinuities.
Industry:Earth science
The dynamic meter divided by 10 go , in which go is some standard value of gravity.
Industry:Earth science
A method of determining geoidal heights from measurements of the acceleration of gravity. The acceleration must be known, theoretically, over the whole world. Stokes's formula or a modification of it is usually used.
Industry:Earth science
A ring supported externally by a pair of trunnions and having internally another pair of trunnions placed so that the axis of the internal pair is perpendicular to the axis of the external pair. The internal pair supports bearings and an axle to which is fastened the object of interest. If the object is initially at rest, it will remain at rest regardless of any rotation of the framework in which the gimbal is placed, except for a rotation in the plane of the ring and except for the amount of motion transmitted through the trunions and bearings by friction. A second gimbal is often nested within the first in such a way that the object remains at rest regardless of the direction in which the supporting framework rotates. Gimbals are used in geodesy and in navigation to support a magnetic or gyroscopic compass so that the indicator remains horizontal. They are also used in inertial surveying systems to allow the gyroscopes to keep fixed orientations.
Industry:Earth science
A unit of acceleration equal to one centimeter per second per second. The milligal, 0.001 gal, is more commonly used in geophysics. However, neither gal nor milligal is an approved unit in the Système International d'Unités.
Industry:Earth science
(1) The sum, from i = 1 to i = I - 1, of the quantities ΔH <sub>i</sub> gi obtained in going from a level surface of reference, through a sequence of level surfaces numbered from i = 1 to i = I - 1, to the level surface through the point for which the equipotential number is wanted. Successive surfaces S <sub>i-1</sub> and S<sub>i</sub> are separated by the very small distance ΔH <sub>i</sub>, expressed in meter and g <sub>i</sub> is the average value of the acceleration of gravity, expressed in kilogals, along the distance ΔH <sub>i</sub>. The equipotential number at a point is approximately equal to the elevation of that point, in meter. (2) The quantity given by the integral<br>
Industry:Earth science
A stake upon which a difference of elevation has been marked. The top of the stake may be driven to the desired difference of elevation or, more commonly, a horizontal mark is made with arrow or crow's foot to mark the difference. If the difference is below the reference level, the distance is marked C for cut. If it is above the reference level, the distance up to the reference level is marked F for fill. Grade stakes are frequently placed on an offset line, with the amount of offset and its direction from the line of survey indicated on the side of the stake.
Industry:Earth science
