The Celestial Frame and the Weighting of the Celestial Pole Offsets in the Computation of VLBI-Based Corrections for the Main Lunisolar Nutation Terms

Very long baseline interferometry (VLBI) is the only technique in space geodesy that can determine directly the celestial pole offsets (CPO). In this paper, we make use of the CPO derived from global VLBI solutions to estimate empirical corrections to the main lunisolar nutation terms included in the IAU 2006/2000A precession-nutation model. In particular, we pay attention to two factors that affect the estimation of such corrections: the celestial reference frame used in the production of the global VLBI solutions and the stochastic model employed in the least-squares adjustment of the corrections. In both cases, we have found that the choice of these aspects has an effect of a few mu as in the estimated corrections.

Automated summary

VLBI is the only technique to directly determine celestial pole offsets. This study uses VLBI data to correct main lunisolar nutation terms in the IAU 2006/2000A precession-nutation model, finding that the choice of celestial reference frame and stochastic model can have a small effect on the estimated corrections.