***************************************************************************= *** dorismail 09-Aug-2023 13:59:05 Message No 1361 ***************************************************************************= *** Author: "Lemoine, Frank G. (GSFC-61A0)" Subject: Updated ITRF2020 UT1/LOD series ************************************************************************ IERS Message No. 485 August 09, 2023 ************************************************************************ Updated ITRF2020 UT1/LOD series Dear colleagues, The UT1 and LOD values initially published with ITRF2020 were recently discovered to be erroneous. The issue could be traced back to a sign error in the LOD zonal tide corrections applied by the IVS Combination Center when propagating their ITRF2020 inputs from the middle epochs of the VLBI sessions to noon. The impact of this error on the UT1 and LOD values initially published with ITRF2020 was of the order of a few tenths of milliseconds. ITRF2020 EOP time series with corrected UT1 and LOD values are now available at: * ftp://itrf-ftp.ign.fr/pub/itrf/itrf2020/ITRF2020_EOP-F1.DAT * ftp://itrf-ftp.ign.fr/pub/itrf/itrf2020/ITRF2020_EOP-F1.DAT and through the ITRF2020 web page at https://itrf.ign.fr/en/solutions/ITRF2020. These files replace the previous erroneous ones. Users who downloaded either of those two files before 9 August 2023 are advised to download them again. As the impact of the error on all other ITRF2020 parameters (pole coordinates and rates, station coordinates) is completely insignificant, all other ITRF2020 files have been left unchanged. Best regards, Paul Rebischung, on behalf of the IERS ITRS Center= Please do not reply directly to this message, but send comments and suggestions to IDS.central.bureau@cls.fr