- Industry: 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, ...
Cut off or trim unwanted parts of a photograph. It is usually done by masking the image during printing.
Industry:Earth science
Adjustment of the reference ellipsoid, for a particular geodetic datum, so that the differences between the geoidal heights determined from gravimetric and astrogeodetic surveys are (usually in a least-squares sense) minimized.
Industry:Earth science
Measurements made across opposite corners of the outside lines of a graticule to check the accuracy of the graticule or to check the scale of the graticule. A diagonal check has meaning only for graticules bounded by rectangles.
Industry:Earth science
An instrument which measures rate of flow in rivers and oceans by transmitting acoustic pulses in opposite directions parallel to the flow and measuring the difference in the time it takes a pulse to travel between transmitter and receiver.
Industry:Earth science
A tidal constituent which, together with the lunar diurnal constituent, expresses the effect of the Moon's declination on the tides. The two constituents together account for the diurnal inequality and, at extremes, diurnal tides. With constituent P1, it expresses the effect of the Sun's declination. Its period is 23. 92 hours, its angular speed is 15. 0411 degrees per hour. Its symbol is K1; the Doodson number is 165. 555.
Industry:Earth science
An array of metal-oxide semiconductors or photodiode semiconductors in which the light falling on each semiconductor builds up a charge proportional to the integrated intensity of the light. The charges are collected in capacitors and then transferred from the array to an amplifier whose output is a sequence of corresponding voltages. The voltages are digitized and the values stored or used immediately for constructing an image.
Industry:Earth science
A term in a Fourier-series representation of the variation of the tide producing potential.
Industry:Earth science
(1) The actual difference in photographic density between the highlights and the shadows on a negative or positive. Contrast indicates not the magnitude of photographic densities but the differences of such densities. (2) The rating of a photographic material, corresponding to the relative difference in density which it is capable of reproducing.
Industry:Earth science
