- 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 orbit described by a body of negligible mass acted upon by a single force located at a point.
Industry:Earth science
Any map projection which is not azimuthal, cylindrical or conical.
Industry:Earth science
A target-leveling rod in two pieces, with movable target, graduated to hundredths of a foot, and read by vernier to thousandths. If the line of sight is more than 6½ feet above the foot of the rod, the target is clamped at 6½ feet and raised by extending the rod.
Industry:Earth science
One of the four planets commonly used for celestial navigation: Venus, Mars, Jupiter and Saturn.
Industry:Earth science
The instant, at a point on the Earth, when the apparent Sun (i.e., the true or actual Sun) is over the upper branch of the meridian of that point.
Industry:Earth science
Aerial photography in which data on the height, with respect to some pre-established datum, of the terrain along the ground vertically below the aircraft are obtained at the same time as the photographs are taken. The terrain-profile recorder is commonly used as the measuring instrument. The recorder actually measures the distance of the aircraft above the ground. The location of the aircraft with respect to some datum is determined by other means, and the height of the terrain is then obtained by combining the two sets of information.
Industry:Earth science
A photograph prepared from a perspective photograph by removing those displacements of points caused by tilt, relief and central projection (perspective). Sometimes called an orthophotomap.
Industry:Earth science
Surveying done by timing the instants at which selected stars are occulted by the Moon. At the instant when the star is occulted, the observer lies on an almost straight line joining his location, the star and a point on the Moon's edge. Other points of observation are chosen so that the occultation of the same star occurs at the same point on the Moon's edge but at different times. The intervals between occultations are known functions of the Moon's apparent velocity and of the distances between points of observation. If several sets of observations are made from the same unknown point in conjunction with simultaneous observations from known points, the location of the unknown point with respect to the known points can be determined.
Industry:Earth science
