- 行业: Earth science
- Number of terms: 93452
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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 bearing taken with a magnetic compass and directed oppositely to the direction of the point whose bearing is desired.
Industry:Earth science
A set of numbers (or symbols representing numbers), objects, or points placed at regular intervals. The numbers, etc. , are called elements of the set and of the array. Note that matrix and array are not the same thing. A matrix is an array whose elements obey certain rules. An array, in general, does not have any special rules associated with it.
Industry:Earth science
The structure, usually of reinforced concrete, supporting an end of an arch or bridge and holding the abutting earth in place.
Industry:Earth science
The method of adjusting a survey traverse by using angles between successive courses as the measured quantities.
Industry:Earth science
The length of the arc passed over by a pendulum in moving from its average position to the position of greatest displacement.
Industry:Earth science
The complement of the interlocking angle. The angular depression of the oblique photograph when the tilt of the vertical photograph is zero.
Industry:Earth science
Determination of astronomic azimuth by measuring the Sun's angular elevation, the angle of the marker from the Sun at that instant and the time of measurement. The formula is cot²(½ A <sub>s</sub>) = (sin½ (S - φ<sub>a</sub>) sin(S + θ))/(cos S cos (S + δ)). The Sun's azimuth is A<sub>s</sub>, the astronomic latitude of the observer is φ<sub>a</sub>, the zenith distance of the Sun is θ (90° - measured angular elevation), the Sun's declination at the instant of observation is δ and S is the quantity (ö<sub>a</sub> - θ - δ). The azimuth of the Sun is added to the measured angle of the marker with respect to the Sun to get the azimuth of the marker.
Industry:Earth science
A sequence of wavelengths or frequencies lying between two given values.
Industry:Earth science
Regulations (zoning) that govern land use, heights of buildings, and natural growth in the region surrounding an airport.
Industry:Earth science
A device in which an input of varying voltage, current, or power is amplified. Any electronic distance measuring instrument, angle measuring instrument or frequency measuring instrument depends on an amplifier to increase the strength of faint, returned signals to the point that the signals can be measured accurately.
Industry:Earth science
