- 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 angle between two meridians. (2) The difference between the hour angle of a celestial body and the hour angle used as argument for entering a table.
Industry:Earth science
The ration between the change in volume of a small part of body, in passing from an unstrained state to a strained state, and the value of that part in the unstrained state.
Industry:Earth science
Displacement of images of ground points from their expected locations on a panoramic photograph because the scanning axis is tipped in the vertical plane through the direction of flight. This distortion is small and adds directly to the distortion caused by the cylindrical projection and by incomplete compensation for image motion and other factors.
Industry:Earth science
In photography with a panoramic camera, the displacement of the images of points on the ground from their expected locations on the cylindrical surface of the film because the lens system or surface of the film was translated to compensate for motion of the image during exposure.
Industry:Earth science
The measurement of a distance between two points. Distance measurement involves the actual measurement of dis-tance; distance determination involves the calculation of distance from a given distance or from some quantity other than distance such as time or angle. The distinction is often not clear and the two terms are then equivalent. Distance measurement is sometimes called telemetry. However, such usage has deprecated because telemetry is used to mean measurement at a distance.
Industry:Earth science
The algebraic sum of the divergence (partials) for the sections of a level line, from the beginning of the line to the end of any section at which the total divergence is to be computed.
Industry:Earth science
A unit of measurement for the magnifying power of a lens, equal to the reciprocal of the focal length in meters. dioptric (adj. ) Containing only refractive elements (lenses and/or prisms).
Industry:Earth science
A horizontal direction expressed as an angle from astronomic north.
Industry:Earth science
(1) A straight line drawn from one point on a ellipse to the point on the other side and passing through the center of the ellipse. The diameters of an ellipse vary in size. That diameter passing through a focus is longer than any other diameter; that diameter perpendicular to the longest diameter is shorter than any other diameter. If the ellipse is a circle, all diameters are of equal length, but a diameter is longer than any other line drawn from side to side and not passing through the center. (2) A measure of the degree of magnification or enlarge-ment of an object or figure. If a circle has a diameter of 1 unit and it is magnified to a circle with a diameter of 2 units, the magnification is said to be 2 diameters.
Industry:Earth science
