- 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 hypothetical photograph, theoretically taken by a camera having the optical axis vertical and taken at the same camera station as the actual photograph.
Industry:Earth science
(1) The reconstruction (mathematically or in a photogrammetric instrument) of the same geometric relationships, except for scale, between a pair of photographs that existed when the photographs were taken. In photogrammetric plotters, this is achieved by a systematic sequence of rotational or translational movements of the projectors. It is then sometimes called clearing y-parallax. (2) The placing of two photographs in the same relative position, except for scale, that they had when they were taken. If the two photographs have enough pairs of image-points corresponding to the same object points (at least 5), the one photograph can be oriented relatively to the other.
Industry:Earth science
The physical structure that marks the location of an initial point in the rectangular system of surveys.
Industry:Earth science
A planet which is farther, on the average, from the Sun than is the Earth.
Industry:Earth science
(1) A person who brings an action (at law). (2) The party who complains or sues in a personal action and is so named on the record.
Industry:Earth science
A pendulum having an initial momentum imparted to it by mechanical or other means and moving afterwards wholly under the influence of gravity. In measuring gravity, the initial momentum can be imparted by drawing the pendulum slightly out of plumb and then releasing it.
Industry:Earth science
A hypothetical pendulum consisting of a point-mass attached to one end of a massless, rigid rod of zero cross section. The other end of the rod pivots without friction on a horizontal axle of zero radius, so that the point mass is free to oscillate in a vertical plane about the horizontal axis. A real pendulum differs from a simple pendulum in many ways, of which the following are particularly prominent. First, its mass is not concentrated at a point but is distributed over an extended region. Second, the rod is flexible rather than rigid and has a finite cross-section, so that its motion is resisted by the medium in which the pendulum swings. Third, the pivot on which a real pendulum swings is affected by friction. Fourth, the pivot is not an ideal line; the pendulum and pivot are in contact along a surface, and the shape of this surface changes with the position of the pendulum. Lastly, the support for the pivot also flexes and sways. Each of these differences of the real pendulum from a simple pendulum requires that a correction be made to the equation governing the motion of a simple pendulum.
Industry:Earth science
(1) Of a sphere, the plane determined by a specified great circle or, if a diameter of the sphere is specified instead, the plane through the center of the sphere and perpendicular to the specified diameter. (2) Of a rotational ellipsoid, the plane through the center of the ellipsoid and containing the two axes of equal length. On an oblate rotational ellipsoid, the equatorial plane corresponds to the plane center and perpendicular to the shortest axis; on a prolate rotational ellipsoid, it is the plane through the center and perpendicular to the longest axis. (3) Of an ellipsoid with three axes of unequal lengths (a heteraxial ellipsoid), the plane through a specified pair of axes. In geodesy, this is usually the plane through the center and perpendicular to the shortest axis.
Industry:Earth science
The plans, for an engineering project, prepared from data obtained in the field by surveying. (jargon).
Industry:Earth science
