************************************************************************ IERS Message No. 473 March 14, 2023 ************************************************************************ Alignment of the IERS Bulletin A to IERS EOP 20 C04 series As of Bulletin A Vol XXXVI, No. 013, on 30 March 2023, the IERS Rapid Service/Prediction Center will transition the EOP solution to be consistent with the 20 C04 for polar motion, UT1-UTC, and celestial pole offsets. This change will result in a difference of less than a RMS of 0.05 mas in polar motion and 10 us in UT1-UTC. The only users who need to be concerned with this change are those who need EOP accuracy to be better than 0.1 mas (~0.3 cm at the Earth's surface, ~1.2 cm at GPS orbit.) A notice of the change will be contained near the top of the IERS Bulletin A Vol XXXVI, No. 013, on 30 March 2023, where notes to users are placed. Users are strongly encouraged to review this message to confirm the change or to note if the change was not implemented due to technical issues. Nick Stamatakos, IERS Rapid Service / Prediction Centre: Primary scientist and representative to the IERS Directing Board Sharyl Byram, IERS Rapid Service / Prediction Centre: Production director and lead project scientist ************************************************************************ IERS Messages are edited and distributed by the IERS Central Bureau. If not stated otherwise, the IERS is only the distributor of the message and is not responsible for its content. To submit texts for distribution, please write to . To subscribe or unsubscribe, please create an IERS account or modify it: https://www.iers.org/Login/Login/EN/login_node.html or write to . Archives: http://www.iers.org/IERS/Messages ************************************************************************