- 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, ...
An architectural drawing showing the precise details of construction and where equipment and utility lines are located.
Industry:Earth science
A scanner in which the image being scanned is placed on a rotating drum which rotates slowly while the scanning beam moves rapidly back and forth parallel to the axis of rotation.
Industry:Earth science
(1) The slow motion of a body under the influence of external forces. In particular, the gradual lateral movement of a ship or aircraft caused by currents, winds, or other external forces acting laterally. Aerial photographs taken without rotating the camera to compensate for drift of the aircraft results in a sequence of pictures with sides approximately parallel but with centers displaced laterally by the amount of drift between exposures. This condition is known as crab. Also, the gradual horizontal movement of large, continent sized parts of the Earth's crust. This is known as continental drift or, with some modification, plate motion. (2) The slow and secular change in precision or accuracy of an instrument. For example, the slow changes in readings of a gravimeter, caused by changes in the instrument's structure, is called drift. (3) The vertical component of that part of the precession of the rotational axis of a gyroscope which is caused by the Earth's rotation. (4) All clay, silt, sand, gravel and boulders transported by a glacier and deposited by or from the glacier directly or by water running from the glacier. (5) A horizontal opening in or near a mineral deposit and parallel to the course of the vein or long dimension of the deposit.
Industry:Earth science
(1) The surface obtained by assigning to the spheropotential function a value such that the volume inclosed by the resulting surface is the same as the volume inclosed by the geoid. Because the volume of the Earth is not directly measurable but must be calculated from data on elevations of the Earth's surface above the geoid and on geoidal heights, the Earth spherop is known only approximately. (2) A spherop containing a volume equal to that contained in the geoid.
Industry:Earth science
The quantity e' defined, for a conic section, as e' ≡ √ ( (1/k²) (a/b)² - 1), in which a is half the length of the major axis, b is half the length of the minor axis and k² is a constant equal to +1 for an ellipse, 0 for a parabola and 1 for a hyperbola. It is related to the eccentricity (first eccentricity) by the equation.
Industry:Earth science
The lowering of the recorded level of water, at a tide gage, caused by the presence of streams near the tide gage.
Industry:Earth science
The error which occurs, in determining the radial velocity of a source by using Doppler radar, because of atmospheric refraction. Such an error may result from (a) the false assumption of a constant wave velocity in a non - homogeneous atmosphere or (b) the refraction of the ray so that the ray's path deviates from the straight line between radar source.
Industry:Earth science
The privilege, by operation of law, to use the land of another for a particular purpose that arises in connection with a conveyance when it was obvious that continued use before the conveyance was meant to be permanent and reasonably necessary for beneficial enjoyment of the land conveyed or retained.
Industry:Earth science
The difference between the frequency fo of radiation received at a point and the frequency fs of the radiation when it was emitted, when observer and source are moving with respect to each other. If relativistic effects are ignored, the Doppler shift is given by Δf ≡ f <sub>o</sub> - f <sub>s</sub> = f <sub>s</sub> ((c + v) / (c - v)) ½ , in which c is the speed of the radiation and v is the speed of the observer with respect to the source (positive for the two points moving apart).
Industry:Earth science
A company announcement of earnings that differ from analysts' prevailing expectations.
Industry:Earth science
