Implementation of the IERS 2020 C04 system on 14 February 2023

It was announced that IERS will be implementing the 2020 International Terrestrial Reference Frame (ITRF2020) and making it available in its EOP products on 14 February 2023. More details can be found in IERS Message No. 471.

We would like to distinguish predictions based on EOP 14 C04 data from those based on new EOP 20 C04 series. Therefore, we ask you to keep the same file names as before for predictions connected with previous C04. For predictions based on new 20 C04 data, please add suffix “_2020” to the file names, e.g. “eoppcc_999_59976_2020” or “eoppcc_999_59976_p_2020”. The content of the files, format and units are not changed. We do not require you to switch to 20 C04 at a specific date. During the transition period you can send predictions related to EOP 14 C04 data or both EOP 14 C04 and EOP 20 C04. What is important for us is the information whether the given predictions are related to the previous or the latest C04 realization (without or with „_2020” suffix in the filename).

We would like to thank all of you for active participation in the campaign.