On the performance of the corrections to the current precession-nutation models in VLBI data analysis

<p>The derivation and subsequent use of suitable corrections to the current IAU2006/IAU2000 precession/nutation models is a main objective of the IAU/IAG Joint Working Group on Improving theories and models of the Earth rotation (JWG ITMER). It has been recognized in the latter IERS/GGOS Unified Analysis Workshops as the fastest way of improving the accuracy of those models at the short-term and thus contributing to the development of the last Resolutions of the IAG and IAU on Earth rotation.</p> <p>In the last few years, some research groups have proposed different sets of corrections or updates to precession and either the forced or free nutations &#8211; including alternative approaches to free core nutation (FCN) models. The derivations of the various sets are related to VLBI solutions or observational data to quite different extents. The purpose of this study is providing a wider view into the performance of such corrections, focusing on features and capabilities more directly related to VLBI data analysis</p>