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The IERS was established as the International Earth Rotation Service in 1987 by the International Astronomical Union and the International Union of Geodesy and Geophysics and it began operation on 1 January 1988. In 2003 it was renamed to International Earth Rotation and Reference Systems Service.

The primary objectives of the IERS are to serve the astronomical, geodetic and geophysical communities by providing the following:

  • The International Celestial Reference System (ICRS) and its realization, the International Celestial Reference Frame (ICRF).
  • The International Terrestrial Reference System (ITRS) and its realization, the International Terrestrial Reference Frame (ITRF).
  • Earth orientation parameters required to study earth orientation variations and to transform between the ICRF and the ITRF.
  • Geophysical data to interpret time/space variations in the ICRF, ITRF or earth orientation parameters, and model such variations.
  • Standards, constants and models (i.e., conventions) encouraging international adherence.

As of 1 January 2001 the IERS has got a new structure, which is also reflected in this new Web site.

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