International Earth Rotation and Reference Systems Service

"IERS" redirects here. For other uses, see IERS (disambiguation).

International Earth Rotation and Reference Systems Service
The IERS logo
Abbreviation	IERS
Website	http://www.iers.org/

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

History

The IERS was established in its present form in 1987 by the International Astronomical Union and the International Union of Geodesy and Geophysics, replacing the earlier International Polar Motion Service (IPMS) and the Earth rotation section of the Bureau International de l'Heure (BIH). The service began operation on January 1, 1988. Since its inception, the IERS has established new bureaus including the GPS Coordinating Centre in 1990, the DORIS Coordinating Centre in 1994 and the GGF Coordinating Centre in 1998. The organization was formerly known as International Earth Rotation Service until 2003 when it formally changed its name to its present form, in which the organization chose to retain the acronym IERS.

Function

The IERS has various components located in the United States, Europe and Australia. Among its other functions, the IERS is responsible for announcing leap seconds.

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. Other services of IERS are at the Paris Observatory.

UT1 is the non-uniform time defined based on the Earth's rotation.

It defined the IERS Reference Meridian, the International Terrestrial Reference System (ITRS), and subsequent International Terrestrial Reference Frames (ITRF). Related coordinate systems are used by satellite navigation systems like GPS and Galileo: WGS84 and GTRF. The definitions and relationships among ITRF, ICRF and EOP are established by IERS conventions standards. As of 2016, the most recent convention is the IERS Conventions (2010).^[1]

Earth orientation products

A mission of the IERS is to provide earth orientation information to the greater geodesy community in the form of bulletins:^[2]^[3]

Bulletin A provides a rapid turnaround service for providing current EOP and a prediction model for EOP up to a year in the future. It is released weekly.
Bulletin B provides final measurements of EOP and is released monthly.
Bulletin C provides announcements of leap seconds
Bulletin D provides DUT1 = (UT1-UTC) to a 0.1 second precision.

References

↑ "IERS Conventions Center". 62.161.69.131. IERS. Retrieved 2 August 2016.
↑ "Earth Orientation Center". Observatoire de Paris. Retrieved 2 August 2016.
↑ "IERS Rapid Service/Prediction Center for Earth Orientation Parameters". U.S. Naval Observatory. Retrieved 2 August 2016.

Altamimi, Zuheir; Collilieux, Xavier (2013) Reference Frames for Applications in Geosciences Berlin; New York: Springer ISBN 3642329985, pg 57.
Gupta, Harsh K. (2011) Encyclopedia of Solid Earth Geophysics Springer ISBN 904818701X, pg 128.
McCarthy, Dennis D.; Seidelmann, P. Kenneth (2009) Time: From Earth Rotation to Atomic Physics John Wiley & Sons ISBN 3527627952, pg 290.

External links

Official website
(English) (French) (Russian) Earth Orientation Center of the IERS : data and interactive analysis (Paris Observatory)
(English) (French) International Celestial Reference Frame of the IERS

Time measurement and standards

Chronometry Orders of magnitude Metrology

International standards	UTC UTC offset UT ΔT DUT1 IERS ISO 31-1 ISO 8601 TAI 12-hour clock 24-hour clock Barycentric Coordinate Time Barycentric Dynamical Time Civil time Daylight saving time Geocentric Coordinate Time International Date Line Leap second Solar time Terrestrial Time Time zone

Obsolete standards	Ephemeris time Greenwich Mean Time Prime meridian

Time in physics	Absolute time and space Spacetime Chronon Continuous time Coordinate time Cosmological decade Discrete time Planck epoch Planck time Proper time Theory of relativity Time dilation Gravitational time dilation Time domain T-symmetry

Horology	Clock Astrarium Atomic clock Complication History of timekeeping devices Hourglass Marine chronometer Marine sandglass Radio clock Watch Water clock Sundial Dialing scales Equation of time History of sundials Sundial markup schema

Calendar	Astronomical Dominical letter Epact Equinox Gregorian Hebrew Hindu Intercalation Islamic Julian Leap year Lunar Lunisolar Solar Solstice Tropical year Weekday determination Weekday names

Archaeology and geology	Chronological dating Dating methodologies in archaeology Geologic time scale International Commission on Stratigraphy

Astronomical chronology	Galactic year Nuclear timescale Precession Sidereal time

Units of time	Century Day Decade Fortnight Hour Jiffy Lustrum Millennium Minute Moment Month Paksha Saeculum Second Shake Tide Week Year

Related topics	Chronology Duration music Mental chronometry Metric time System time Time value of money Timekeeper

This article is issued from Wikipedia - version of the 11/5/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.