International Earth Rotation and Reference Systems Service - Definition and Overview

The International Earth Rotation Service (IERS) is the body responsible for maintaining global time and reference frame standards, notably through its Earth Orientation Paramater (EOP) and International Celestial Reference System (ICRS) groups.

Among other functions, it decides when to issue leap seconds.

The organization formally changed their name to the International Earth Rotation and Reference Systems Service on April 2, 2002 while electing to retain the acronym IERS.

The Sub-bureau for Rapid Service and Predictions of Earth Orientation Parameters of the IERS, located at the United States Naval Observatory, monitors the Earth's rotation. Part of its mission involves the determination of a time scale based on the current rate of the rotation of the Earth. UT1 is the non-uniform time based on the Earth's rotation.

See also

• International Atomic Time
• Coordinated Universal Time
• International Terrestrial Reference System
• International Celestial Reference System
• ΔT

External links

• IERS's web site (http://www.iers.org)
• another web site (http://hpiers.obspm.fr/)
• IERS Bulletin C, where leap seconds are announced (http://www.iers.org/iers/publications/bulletins/bull_c/)
• IERS Archive, to view old announcements (http://www.iers.org/iers/earth/rotation/utc/table2.html)
• Public domain article on leap seconds (http://tycho.usno.navy.mil/leapsec.html)