- 行业: 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 correlation of the members of a time series with each other.
Industry:Earth science
One of a set of three angles (<font face = symbol>q</font><sub>1</sub>, <font face = symbol>q</font><sub>2</sub>, <font face = symbol>q</font><sub>3</sub>) specifying the orientation of the axes (x,y,z) of one rectangular, Cartesian coordinate system with respect to the corresponding axes (X,Y,Z) of another. Rotations generating the angles are about each of the x,y,z axes, successively, in their original positions. In general, the amounts of rotation required to obtain the needed angles are not simply described. If, however, the axes of the two systems are close together, the pseudo Cardan angles are approximately the same as the Cardan angles. Pseudo Cardan angles have been used in photogrammetry.
Industry:Earth science
The assessment, in a fair and objective manner, of the accuracy and usefulness of a map.
Industry:Earth science
An azimuth measured with respect to lines whose directions are established by a gyrocompass. In particular, an azimuth measured using a gyrotheodolite (gyroscopic theodolite).
Industry:Earth science
The angle obtained by pointing the telescope of a transit at an object, reading the angle on the vertical circle, then reversing the instrument to put the vertical circle on the other side of the observer, redirecting the telescope at the object, and reading the new angle on the vertical circle. The difference of the two readings is the double zenith angle and is twice the zenith angle. Double zenith angles are used in trigonometric leveling and in astronomy because they are little affected by inclination of the vertical axis of the instrument used. Only certain types of transit, however, allow double zenith angles to be measured.
Industry:Earth science
A horizontal control datum defined by the following location and azimuth on the Clarke spheroid of 1880 (modified); the origin is at station Zv ADINDAN:<br>
Industry:Earth science
(1) The square root of the average of the sum of the squares of the differences between (a) a set of measured or calculated values and a (b) set of corresponding correct values, divided by the average value of the set. i.e., relative accuracy is equal to the accuracy divided by the average value of the set. This is a useful quantity because it is dimensionless and independent of the units in which the measurements were made.
(2) A quantity expressing the effect of random errors on the location of one point or feature with respect to another. In particular, (a) an evaluation of the effect of the random errors in points on a map with respect to the graticule, excluding any errors in the graticule or the coordinate system of the graticule; or (b) an evaluation of the effect of random errors in determining the location of one point on a map with respect to another point on the same map.
Industry:Earth science
A prism system consisting of two double right-angle prisms and reflecting an incoming ray four times to give an erect, inverted image.
Industry:Earth science
An angle whose vertex is at a specified center of the Earth. Centers commonly specified are the center of mass, the center of an ellipsoid representing the geoid, and the center of an ellipsoidal solid representing the Earth.
Industry:Earth science
