Geodetic Reference Systems
Definition of the various Geodetic Reference Systems and their realizations is not only important with regard to scientific work, but will also be of major importance for the practical applications in the fields of geodesy and navigation if seen against the background of an ever-increasing use of space geodetic techniques, as e.g. GPS and the future Galileo System.
With the definition of the reference systems the speed of light, the radius and the flattening of the earth, a Cartesian coordinate system etc. are exemplarily defined.
The individual reference systems are realized at the earth’s surface as reference frames through marked points (survey points) with their coordinates.
Global terrestrial reference systems are Cartesian coordinates having their origin in the earth’s center of mass and their orientation aligned with the rotational axis of the earth. The national coordinate and height systems may constitute local reference systems with their own reference ellipsoids, geoid models and map projections, and also densifications of the global reference frame.