- Domeniu: 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 code (1) which uses a combination of letters and numbers to convey information.
Industry:Earth science
An assemblage of two similar cameras mounted on opposite ends of a short, rigid bar and having their optical axes parallel. It is used in terrestrial photogrammetry for taking stereoscopic pairs of photographs.
Industry:Earth science
The use of a wide range of hues or shades to exaggerate otherwise small variations of photographic density on black and white images, or of hue and shade on colored images.
Industry:Earth science
A fictitious, vertical cylinder whose upper surface passes through a point P on the Earth's surface, whose axis passes through P and is perpendicular to the terrestrial ellipsoid, and whose height is equal to the height of P above the ellipsoid. The radius is arbitrary but is usually between 40 km and 100 km. The cylinder is assumed to be filled with matter, a density of 2. 67 g/cc being usual.
Industry:Earth science
A calendar applied to dating events that occurred outside the period for which the calendar was originally defined. In particular, a calendar extended to date events that occurred before the officially established starting date of the calendar. e.g., the date, 49 B. C. , of Caesar's crossing the Rubicon is a date in the proleptic Gregorian calendar.
Industry:Earth science
(1) In general, a straight line joining two points on a curve or surface. (2) (land surveying) On a great circle, the arc connecting any two corners on a baseline, standard parallel or township's latitudinal boundary. (3) (route surveying) A straight line between two points on a curve, regardless of the distance between them.
Industry:Earth science
That vertical circle through the North and South points on the horizon, which coincides with the celestial meridian.
Industry:Earth science
An instrument for producing a graphical record of the time, shown by a clock or other device, at which an event occurs. In use, a chronograph produces a double record. The first is made by the associated clock and forms a continuous line with significant marks indicating periodic beats of the clock. The second is made by some external agency, human or mechanical, and records the occurrence of an event or series of events (which may be the beats produced by a second clock). The times, as shown by the clock, of such occurrences are read from the record made by the chronograph. In observations for time and longitude, the occurrences of stellar observations are recorded on the chronograph either manually by pressing a key at the instant a star is bisected by a line of the reticle of the telescope used in the observing, or automatically by keeping a star bisected by a movable wire as it travels across the field of view. (SEE transit micrometer). In determining longitudes, the chronograph also records the time at which signals are received from the station of known longitude. The chronograph has been replaced, by many organizations, by equipment which records digitally, on magnetic tape, the time at which an event occurs.
Industry:Earth science
(1) The line that forms the boundary between the coast and the shore and marks the seaward limit of the permanently exposed coast. (2) The U. S. National Ocean Survey uses the terms coastline and shoreline as synonyms and defines them as being the line of mean high water. (3) The U. S. Submerged Lands Act, 43 U. S. C. 1301(c), states that the term coast line means the line of mean low water along that portion of the coast which is in direct contact with the open sea and the line marking the seaward limit of inland waters. (4) A narrow strip of land adjacent to the line separating the surfaces of land and water at the edge of a sea or ocean. This last definition is used in civil engineering and is best not used at all. Use coast instead.
Industry:Earth science
