- 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, ...
An error, in a stereoscopic plotting instrument, resulting from improper calibration of the camera, printer used for making the diapositive, or the projector. The error is of little importance in a model of a flat surface, but the effects of the error increase in proportion to the relief in the model.
Industry:Earth science
Two precisely parallel, flat, transparent (usually glass) plates, usually a few wavelengths apart, through which light is transmitted so as to cause interference. The plates may be made more reflective by thin, metallic films.
Industry:Earth science
An equation relating the lengths r<sub>1</sub> and r<sub>2</sub> of two radius vectors in a parabolic orbit to the length of chord and interval of time between them. Denoting the length of the chord joining the ends of the radii by s and the interval of time by t<sub>2</sub> - t<sub>1</sub>, Euler's equation is 6k (t<sub>2</sub> - t<sub>1</sub>) = (r<sub>1</sub> + r<sub>2</sub> + s)<sup>3/2</sup> ± (r<sub>1</sub> + r<sub>2</sub> - s)<sup>3/2</sup> in which k² is the gravitational constant.
Industry:Earth science
Distance-measuring equipment which contains an optical system essential to the measuring process; in particular, distance measuring equipment which contains an optical distance measuring instrument as one component. There are at least two types: that which involves the formation of an image, and that which involves the modulation of light. The first type includes the equipment used in the stadia method of measuring distances. The second includes the Väisälä base line apparatus and electro-optical distance measuring instruments with reflectors.
Industry:Earth science
A systematic error arising from imperfections in the instrument used. Instrumental errors may arise from imperfections which are built into an instrument, such as errors in the graduation of a horizontal circle, or they may arise from lack of complete adjustment of some part of the instrument, such as the error of collimation. They can be determined in the laboratory. They may be eliminated from a result by a suitable process of measurement or by applying suitable corrections.
Industry:Earth science
That factor which is applied to measures of distance to give the equivalent distance on a specified datum.
Industry:Earth science
An error caused by an incomplete or deficient component of an instrument e.g., backlash in a gear train.
Industry:Earth science
That component, of the difference between the location of a satellite's location as computed from theory and the location estimated from observations by the method of least squares, which lies in the direction of the satellite's velocity at a particular instant.
Industry:Earth science
The value, taken without regard to sign, of the difference between some value of a quantity and the true value of that quantity.
Industry:Earth science
