Reference Coordinate System - Mathematical method of describing spatial position relative to an origin point. The positional vector coordinates specify direction and separation from the origin. Also known as Coordinate System, Coordinate Frame, Frame of Reference, Reference Frame.

See tutorial:  REFERENCE COORDINATE SYSTEM AND TRANSFORMATIONS   for a more thorough overview.

• Often a point, a line, and a plane are used as datums to specify a three dimensional reference coordinate system for metrology.

• The positions of objects on earth are given by a spherical coordinate system which uses angular longitude and latitude coordinates and relative distance from sea level.

• Angular orientation between objects is possible if a reference system is rigidly associated with each object and provided enough information is known relating the reference systems.

• Common machine tool metrology reference coordinate systems are: tool coordinate system ; table coordinate system; workpiece, part or local coordinate system; carriage coordinate system; frame coordinate system; and error coordinate system.