- Branche: 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, ...
An image in which the shading is such that the normal impression of hollows and elevations (relief, in aerial photography) is reversed, with high points on the object appearing to be low and low points appearing to be high.
Industry:Earth science
An alloy of iron containing about 64% iron, 36% nickel, and small amounts of chromium to increase hardness, manganese to facilitate drawing, and carbon to raise the elastic limit, and having a very low coefficient of thermal expansion (about 1/25 that of steel). Also spelled invar. It was invented by C. Guillaume of the International Bureau of Weights and Measures (Paris). It is used wherever a metal does not change its dimensions appreciably with temperature as desired. For this reason, it or a similar alloy has replaced steel in surveyor's tapes and wires, and particularly in those tapes and wires used for measuring geodetic baselines. It is also used for the scale of some leveling rods, in first order leveling instruments, and in pendulums.
Industry:Earth science
In leveling, the difference in distances from the leveling instrument to the two leveling rods (or two locations of one leveling rod)
Industry:Earth science
The determination of tilt by comparing the holes in transparent templets used in a radial adjustment with the locations, on the photographs, of the corresponding points.
Industry:Earth science
The floor, bottom or lowest part of the internal cross-section of a conduit.
Industry:Earth science
A Julian day number from which a specified constant has been subtracted. The constant can be assumed to be 2 400 000.5 unless otherwise stated.
Industry:Earth science
A deviation from elliptical motion of the Moon, caused by attraction of the moon by the Earth, Sun and other bodies in the Solar System.
Industry:Earth science
A distance-measuring instrument operating at infrared wavelengths.
Industry:Earth science
A short, narrow body of water with channels at ends diverging at 90<sup>o</sup> to 180<sup>o</sup>, connecting a bay, lagoon or similar body of water with a large parent body of water (usually an ocean), and wetted wholly or in part by the tides.
Industry:Earth science
The (principally) vertical movement of some bench marks because of local changes in the nature of the material surrounding the bench mark or movement of that material. The cause of the instability is usually within about 15 meters of the surface; it may, however, be considerably more deep-rooted.
Industry:Earth science
