- 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, ...
(1a) Geometrically, a surface such that a straight line connecting any two points of the surface lies entirely on the surface and contains at least three distinct points of that surface. (b) Algebraically, the surface defined by all values of x, y, z satisfying the equation ax + by + cz = d, in which a, b, c, d are constants. (2) A small region on a level surface, as, for example, in the term plane surveying.
Industry:Earth science
The distance between the beginning and final points of a closed traverse, as calculated from the measurements.
Industry:Earth science
Photography done so precisely as give results that can be used to give precise information on the locations and positions of the objects photographed.
Industry:Earth science
Twin low-oblique photography done using cameras whose optical axes point downwards and away from each other crosswise of the line of flight. This kind of photography gives increased angular coverage.
Industry:Earth science
(1) A short line perpendicular to a surveyed line and measured to a line or point for which data are desired, thus locating the second line or point with respect to the surveyed line. Offsets may be measured from a surveyed line or lines to the edges of an irregular body of water or to any irregular line whose position is wanted.
Industry:Earth science
An orbital perturbation caused by the pressure of electromagnetic radiation on a satellite. The principal cause of radiation pressure perturbations is solar, electromagnetic radiation pressing on the satellite. It may come either directly from the Sun or may arrive indirectly by reflection and scattering from the Earth. Particulate radiation (the solar wind) from the Sun also exerts pressure on satellites but by convention is not considered to be involved in radiation pressure perturbation.
Industry:Earth science
An optical device attached to an aerial camera and allowing the ground and the Sun to be photo-graphed simultaneously. The camera's orientation can be determined in this way without relying on ground control to furnish the orientation. The solar periscope was invented by E. Santoni.
Industry:Earth science
The property, of a map projection, of preserving areas of figures.
Industry:Earth science
That portion of a shadow in which light from an extended source is partially but not completely cut off by the intervening body. I.e., the region of partial shadow surrounding the umbra, the part to which no light penetrates.
Industry:Earth science
A survey marker set vertically below the center of a marker on the surface and separated from it so as to preserve the station in case of an accident to the marker on the surface.
Industry:Earth science
