Hinweis zur Verwendung von Cookies

Cookies erleichtern die Bereitstellung unserer Dienste. Mit der Nutzung unserer Dienste erklären Sie sich damit einverstanden, dass wir Cookies verwenden. Weitere Informationen zum Datenschutz erhalten Sie über den folgenden Link: Datenschutz


Navigation and service

International Earth Rotation and Reference Systems Service

The International Terrestrial Reference System (ITRS)

The ITRS definition fulfills the following conditions:

  1. It is geocentric, the center of mass being defined for the whole earth, including oceans and atmosphere.
  2. The unit of length is the metre (SI). This scale is consistent with the TCG time coordinate for a geocentric local frame, in agreement with IAU and IUGG (1991) resolutions. This is obtained by appropriate relativistic modelling.
  3. Its orientation was initially given by the BIH orientation at 1984.0.
  4. The time evolution of the orientation is ensured by using a no-net-rotation condition with regards to horizontal tectonic motions over the whole earth.

See the

IERS Conventions (2010)

, especially IERS Technical Note 36: 4. Terrestrial reference systems and frames (PDF, 662KB, Not barrier-free file.), for a detailed description of the ITRS.

The ITRS is realized by estimates of the coordinates and velocities of a set of stations observed by VLBI, LLR, GPS, SLR, and DORIS. Its name is International Terrestrial Reference Frame (ITRF).

General documentation on terrestrial reference systems and frames is available at the ITRS Centre of the IERS.

The ITRS can be connected to the International Celestial Reference System (ICRS) by use of the IERS Earth Orientation Parameters (EOP).

Text provided by the former Central Bureau, modified.