The availability of highly accurate global reference frames and Earth Orientation Parameters are of major importance for all positioning and navigation applications on Earth, Sea, Air and also in Space. This is equally true for ESA missions and the EU space programs, e.g. Galileo, EGNOS and Copernicus.

In the frame of its responsibility to provide the Geodetic reference for ESA missions, ESA’s Navigation Support Office at ESOC is contributing to the realisation of the International Terrestrial Reference Frame (ITRF) and the combined Earth Orientation Parameters provided by the International Earth Rotation Service (IERS) . The contribution is realised through individual contributions to international services such as the International GNSS Service (IGS) , the International Laser Ranging Services (ILRS) , the International DORIS Service (IDS) , the International Earth Rotation Service (IERS) . The contribution to the International VLBI Service (IVS) is currently under preparation.

For the combination and long-term predictions of the Earth orientation products ESA is still relying on the International Earth Rotation Service (IERS). Considering the importance of up-to-date Earth orientation parameters, the dependence on a single source outside Europe is considered a risk for European industry, for ESA missions and for EU programmes. For this reason, ESA developed an independent ESA Earth Orientation parameter product, which is currently in the final testing phase. The start of the operational provision is scheduled for the first quarter of 2024.

The ESA Earth Orientation Parameters will be made routinely available in this website.

The geodetic reference activities are supplemented by a time scale realisation at ESOC. UTC(ESA) is a joint activity between the Radio Frequency Systems & Payloads Office in ESTEC, the Station Subsystems Section and the Navigation Support Office in ESOC.