Geodetic reference system 1980

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The Geodetic Reference System 1980 ( GRS 80 , English Geodetic Reference System 1980 ) is an earth model that includes the most important parameters of the earth's shape , the earth's rotation and the gravitational field .

The reference ellipsoid of the GRS 80 serves the European spatial reference system ETRS89 as a geometrical calculation and mapping surface and with it forms the geodetic datum for uniform national surveying . The compliant UTM mapping is used as the mapping system. In Germany, the Gauss-Krüger coordinates related to the Bessel ellipsoid ( Potsdam date ) and the Krassowski ellipsoid ( Pulkovo date ) are converted to GRS80 and UTM.

GRS 80 also defines the normal gravity and thus replaces GRS 67 . WGS 84 practically uses the ellipsoid of the GRS 80 but contains more data about the gravitational field .

GRS 80 was adopted in 1979 at the general assembly of the IUGG , the international umbrella organization for geodesy and geophysics , and published in detail in 1980  by the head of the study group, Helmut Moritz , after consultation with the International Astronomical Union (IAU) .

The four defining geometric and physical parameters are:

Major semi-axis / equator radius
Gravitational constant times earth mass
(more precisely measurable than the individual factors)
Difference in the main moments of inertia related to  M a 2
(without the influence of tidal forces )
Angular velocity
(including information on the orientation of the axis of rotation and the prime meridian )

The derived parameters for describing the shape of the Earth's ellipsoid are:

Small semi-axis / pole half-axis
Parameters of Earth flattening

See also

literature

  • Bernhard Heckmann: Introduction of the ETRS89 / UTM position reference system when switching to ALKIS. In: Communications of the DVW Hessen-Thüringen, 1/2005, p. 17 ff.
  • Ralf Strehmel: Official reference system for the situation - ETRS89. Surveying Brandenburg, 1/1996 ( PDF ).
  • Bernhard Heck: Calculation methods and evaluation models for national surveying. Karlsruhe 1987.
  • Hans-Gert Kahle : Introduction to Higher Geodesy . 2nd, revised and expanded edition. Verlag der Fachvereine, Zurich 1988.
  • International Association of Geodesy (IAG): Geodesist's Handbook 1980.

Web links