- 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, ...
A process for printing shadings consisting of lines, dots, stipples, etc. , by inking a Benday screen (a rectangle of hardened gelatin with the pattern in relief), printing with it on portions of the metallic plate on which an outline has been photographically printed, and then etching the metal as a line plate. Also spelled benday process and Ben Day process. It is named after Benjamin Day, the originator of the process.
Industry:Earth science
That circle of the celestial sphere, centered on the polar axis and having an angular distance from the depressed pole approximately equal to the latitude of the observer, within which celestial bodies are not seen to rise at the observer's latitude. Contrasted to a circle of perpetual apparition.
Industry:Earth science
Classification of the coordinates of a set of points (the survey) produced by a single surveying project. It differs from the classification of control in that the set as a whole rather than the individual points in the set is classified. The practice is to place the survey in the same category as would have been placed a single control point considered characteristic of the points actually produced by the survey. The largest error produced by the survey may be used as a basis, or the average error, or some more complicated function of coordinates and their errors may be used.
Industry:Earth science
The horizontal angle from North, as indicated by a magnetic compass, east or west to the object being sighted, whichever gives the smaller angle. It differs from magnetic bearing in that the latter is corrected for deviation.
Industry:Earth science
An instrument for measurement of color, i.e., for identifying in some unique and standard way the color of an object. One form, used for opaque objects, compares the object with a set of standard colors. Another, used for light-emitting objects such as lamps and stars, compares the light from the object with light of known composition passed through colored filters. Yet another, used for translucent substances such as filters or colored solutions, passes light of known composition through the substance and determines the amount of light absorbed in various parts of the spectrum. A colorimeter differs from a spectrometer primarily in that it gives the color of an object (or the light from it) by specifying how that color can be made up from a small number (from 1 to 3; usually fewer than 9) other, standard colors. A spectrometer gives the color of the light from an object in terms of the intensity of the light as a more or less continuous function of wavelength.
Industry:Earth science
One of a series of aeronautical charts covering the United States of America at a scale of 1:500,000 and suitable for contact or visual navigation.
Industry:Earth science
An instrument which allows two standards of length to be compared by translating the standards parallel to each other. The standards are placed parallel to each other on an bench one part of which can move in the longitudinal direction of the standards.
Industry:Earth science
A chart on which lines (isogons) of constant angle from geodetic north to magnetic north are drawn.
Industry:Earth science
That agency of the U. S. Department of the Interior created by Executive Order effective 16 July 1946 and superseding the General Land office in administering the general land-laws, with supervision of the subdivisional survey, and disposal of title to the public lands of the United States, and of the leasing, grants of right-of-way, and other surficial uses thereof, including all rights incident to the extraction of minerals; coal, phosphates, potash, oil, and gas on the public lands; withdrawals for irrigation, dams, and reservoirs, and for grazing and settlement rights of every description.
Industry:Earth science
