International VLBI Service for Geodesy and Astrometry: Earth orientation parameter combination methodology and quality of the combined products

The analysis coordinator of the International VLBI Service for Geodesy and Astrometry (IVS) regularly disseminates the official IVS products of Earth orientation parameters (EOPs). For 2 years now, these parameters have been produced by combining datum‐free normal equations of up to six IVS analysis centers. In this paper we document the combination methodology, discuss critical issues, and report on the quality of the products. The agreement of the very long baseline interferometry results with the International Global Navigation Satellite Systems (GNSS) Service GPS EOPs is of the order of 18 μ s for length of day and 100 μ as (microarc seconds) and 300 μ as/d for the polar motion components and their rates, respectively.