- 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, ...
Aerial photography done with three cameras arranged at fixed angles to one another in such a way that adjacent photographs, taken simultaneously, overlap. Usually, the cameras are arranged so that the central camera takes vertical photographs and the other two cameras take high-oblique photographs. The assemblage is often referred to as a trimetrogon camera assembly because Metrogon lens-systems were widely used in early photography with three cameras. The process is then called trimetrogon photography. This type of photography has been supplanted, for most purposes, by photography using single cameras having extremely wide fields of view.
Industry:Earth science
Determination of corrections to assumed or approximate coordinates of objects, using phototriangulation.
Industry:Earth science
A line, on a photograph, which passes through the isocenter and is the image of a horizontal line perpendicular to the principal plane of the photograph.
Industry:Earth science
An oblique aerial photograph on which is printed a grid to assist in identifying a particular region or point within the photograph. Gridded obliques are used chiefly for spotting targets for artillery.
Industry:Earth science
One of a set of three photographs obtained by simultaneous exposure from three aerial cameras placed in such a way that the overlap is constant.
Industry:Earth science
Planning for those sort-term and long-term uses of land which will best serve the general welfare, together with formulating ways and means for achieving such uses.
Industry:Earth science
Determination of the astronomic azimuth of a line by measuring, with an ocular micrometer attached to a theodolite or transit is used to measure the horizontal angle between vertical plane through a star and a vertical plane through a marker on the ground (close to the vertical plane through the star). That angle is applied to the azimuth of the star computed for the epoch of the observation to give the azimuth of the marker. At elongation, the apparent motion, in azimuth, of a closely circumpolar star like Polaris is very small for an appreciable length of time, and a series of observations can be made by the micrometer method without re-orienting the instrument. A correction for inclination of the horizontal axis, depending on the angular elevations of the star and of the marker, is applied to the observed angle, and additional corrections are applied for curvature of the apparent path of the star the field of view, for variation of latitude, and for diurnal aberration.
Industry:Earth science
A tidal constituent or tidal-current constituent whose speed is an exact multiple of the speed of one of the fundamental constituents. The presence of overtides is usually attributed to conditions in shallow water.
Industry:Earth science
