- 行业: 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, ...
(1) The direction (azimuth) of the principal plane of a photograph. (2) The direction (azimuth) of the principal line on a photograph.
Industry:Earth science
The distance of a celestial unit expressed in parsecs, light years or astronomical unit.
Industry:Earth science
(1) The angle between a horizontal plane at the observer and a line from the observer to the apparent (i.e., visible) horizon. The apparent horizon lies below the horizontal plane because of the curvature of the Earth, but the amount is affected by upward or downward refraction of light travelling from the horizon to the observer. (2) The vertical angle between the plane of the horizon and a line tangent to the apparent (visible) horizon.
Industry:Earth science
The failure of a lens system to reproduce accurately, to scale, all lengths or distances in the object.
Industry:Earth science
The shortest distance at which an object is acceptably in focus when viewed through an optical system focused at infinity.
Industry:Earth science
The difference between right ascension and oblique ascension.
Industry:Earth science
A set of N unit vectors, radiating from a common point, to which angles are referred in specifying the direction of a point in the space of the vectors.
Industry:Earth science
One of the astronomical directions on the surface of the Earth: north, east, south, west. The term cardinal without qualification, is sometimes used to indicate any or all of the above directions. The exact meaning is then to be inferred from the text.
Industry:Earth science
One of the corresponding distances of object point and image point from the nodal points of a lens. The conjugate distances L <sub>o</sub> and L <sub>i</sub> and the focal length f of the lens are related by the equation 1/f = 1/L <sub>o</sub> + 1/L <sub>i</sub>. The total distance from object point to image point equals the sum of the two conjugate distances plus or minus (depending on the design of the lens) the distance between nodal points.
Industry:Earth science
