About IVS

Working Groups: IERS/IVS Working Group on The Second Realization of the International Celestial Reference Frame (ICRF2)

Purpose The purpose of the working group is to generate the second realization of the ICRF from VLBI observations of extragalactic radio sources, consistent with the current realization of the ITRF and EOP data products. The working group will apply state-of-the-art astronomical and geophysical models in the analysis of the entire relevant S/X astrometric and geodetic VLBI data set. The working group will carefully consider the selection of defining sources and the mitigation of source position variations to improve the stability of the ICRF. The goal is to present the second ICRF to relevant authoritative bodies, e.g. IERS and IVS, and submit the revised ICRF to the IAU Division I Working Group on the Second Realization of the ICRF for adoption at the 2009 IAU General Assembly.

The IERS/IVS Working Group main Web page was maintained at the U.S. Naval Observatory.

Tentative Milestones

Generation of position time series:	first pass - April 2007 update - April 2008
Analysis of position time series:	first pass - October 2007 update - June 2008
Analysis of catalogue noise:	first pass - October 2007 update - June 2008
Source structure catalogue:	first pass - October 2007 update - June 2008
Source structure evolution:	first pass - March 2008 update - June 2008
Selection of stable and/or unstable sources:	July 2008
Selection of defining sources:	August 2008
Second ICRF catalogue:	December 2008
Presentation to IAU WG:	March 2009
Presentation to IAU GA:	August 2009

Working Group Members
Chopo Ma (USA), Chair
Oleg Titov (Australia)
Robert Heinkelmann (Austria)
Sebastien Lambert (Belgium)
Guangli Wang (China)
Felicitas Arias (France)
Patrick Charlot (France)
Anne-Marie Gontier (France)
Jean Souchay (France)
Gerald Engelhardt (Germany)
Axel Nothnagel (Germany)
Volker Tesmer (Germany)
Giuseppe Bianco (Italy)
Zinovy Malkin (Russia)
Julia Sokolova (Russia)
Vladimir Zharov (Russia)
Sergei Bolotin (Ukraine)
David Boboltz (USA)
Alan Fey (USA)
Ralph Gaume (USA)
Chris Jacobs (USA)
Leonid Petrov (USA)
Ojars Sovers (USA)

Reports The IERS/IVS Working Group on the Second Realization of the ICRF was active during the years 2007-2009. The ICRF2 was adopted at the XXVII General Assembly of the International Astronomical Union (IAU) in Rio de Janeiro, Brazil as Resolution B3. The ICRF2 replaced the previously used first realization (ICRF) effective 1 January 2010. A short release note with the full text of the resolution was published as a special report in the IVS 2009 Annual Report. A technical description of the frame was published as IERS Technical Note No. 35. ICRF2 was eventually superseded by ICRF3 effective 1 January 2019.