DORIS Assessment of the 2020 ITRF Realizations

In the context of the 2020 realization of the International Terrestrial Reference Frame, the three IERS Production Centers (DGFI, IGN and JPL) delivered three independent solutions from the contributions of the four space geodetic techniques (DORIS, GNSS, SLR and VLBI). Even if these three ITRF2020 realizations are based on the same input, they differ on several points such as the space geodetic techniques weighting, the coordinate time series discontinuities and on the modelling of the station displacements.

In this study, we use the coordinate time series of the two hundred DORIS stations from 1993.0 to 2021.0 as benchmark to investigate the characteristics of the three ITRF2020 realizations. This set of DORIS station positions correspond to the 1456 weekly solutions delivered by the International DORIS Service (IDS) as the DORIS contribution to the ITRF2020.

After presentation of the overall performance of these three TRF realizations in terms of geocenter, scale and mean velocities, we assess the quality of the weekly restitution of the DORIS station positions by the DTRF2020, ITRF2020 and JTRF2020 solutions. Then, we make benefit of the almost complete year (2021) since the ending of the ITRF2020 time period to evaluate these three 2020 ITRF solutions in terms of prediction of the DORIS station positions.