- 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, ...
The difference between the elevations of the two high tides during a tidal day.
Industry:Earth science
An optical distance-measuring instrument for measuring distances and the difference in phases between radiation sent by a laser from one point to another and the radiation of standard phase within the instrument. Such instruments are used primarily in laboratories and tool-makers' shops for measuring lengths or short distances. Some have been used for establishing short but very accurate base lines.
Industry:Earth science
(1) A line on which all points are at the same pressure. (2) A line (isobaric line), on a chart or map, representing a line, in the Earth, on which all points are at the same pressure. The isobar is most commonly drawn for points in the atmosphere or below the surface of water in oceans, seas, lakes, etc. However, it may be drawn for points in the crust as well.
Industry:Earth science
One of the angles, expressed in units of time, between the various lines of the reticle of an astronomical transit and the average position (central axis) of those lines. The equatorial interval for a given line of a reticle is equal to the length of time required for the image of an equatorial star (declination 0<sup>o</sup>) to travel from the line in question to the central axis of the reticle, or from the central axis to the line in question, the instrument being adjusted in the meridian. In determining time with an astronomical transit, equatorial intervals are used to reduce incomplete measurements to an average value.
Industry:Earth science
The intensity of the horizontal component of the Earth's magnetic field in the plane of the magnetic meridian.
Industry:Earth science
The orientation of the image on a photographic positive or negative relative to the position of the emulsion.
Industry:Earth science
(1) In general, the image or images of a specified object. The image (or images) is said to correspond to or represent the object. (2) In ikonogrammetry, particularly photogrammetry, one of a set of corresponding images (q.v.)
Industry:Earth science
