For Datum we have terms and definitions in 7 topics. The topics are Anthromorphemics, Anthropology, Construction, GPS, Hunting, Real Estate and Sanitation.

Datum (Anthromorphemics)

A fixed reference point on an archaeological site from which measurements are taken.

Datum (Anthropology)

A fixed reference point on an archaeological site from which measurements are taken.

Datum (Construction)

A reference point of starting elevations used in mapping and surveying.

Datum (GPS)

A Datum is a means by which coordinates determined by any means may be related to a well-defined Reference Frame. The Reference Frame may be visualised as a 3-D Cartesian coordinate system consisting, as a minimum, of information concerning the origin of the axes, and the directions of two principal axes fixed to the earth. The Reference Frame may be globally applicable, such as WGS84 or ITRF, in which case it is "geocentric" (having its origin at the earth's centre of mass), or be locally applicable as in the case of traditional national geodetic frames such as the Australian Geodetic Datum. In any case, the Datum may be considered synonymous to the Reference Frame, or be restricted to refer to the set of coordinates of geodetic stations or benchmarks which provide the physical realisation of the Reference Frame. A satellite-defined Datum such as WGS84 may, in addition, be realised by the time-varying coordinates of the satellites themselves (the Ephemerides). Finally, the Datum may be defined only in the horizontal sense or for the vertical component. An example of a Horizontal Datum is a Reference Ellipsoid (located and oriented in such a way as to be compatible to the Reference Frame to which it is attached), upon which coordinate information is expressed in terms of Latitude and Longitude. (WGS84 has a Reference Ellipsoid associated with it.) A Vertical Datum may be defined by a local realisation of Mean Sea Level, or as height above the Reference Ellipsoid.

Datum (Hunting)

Any position or element in relation to which others are determined, as datum point, datum line, datum plane.

Datum (Real Estate)

A horizontal plane from which heights and depths are measured.

Datum (Sanitation)

(1) An agreed standard point or plane or plane of stated elevation, noted by permanent bench marks on some solid immovable structure, from which elevations are measured or to which they are referred. (2) Any position or element in relation to which others are determined; for example, the horizontal control system used in map making. (3) Any numerical or geometrical quantity or set of such quantities which may serve as a reference or base for other quantities.

Similar

Browse words that start with:

• Da
• Dat
• Datum

Browse All Terms by First Letter

Term Search