Analysis of the Accuracy of Prediction of the Celestial Pole Motion

TL;DR

This paper evaluates the accuracy of celestial pole motion predictions using three empirical models, finding that the Pulkovo model provides the most precise forecasts with an RMS error below 100 microarcseconds for one month.

Contribution

It is the first analysis comparing three empirical nutation models' prediction accuracies based on recent observational data.

Findings

Pulkovo model has the highest prediction accuracy.

One-month prediction RMS error is below 100 microarcseconds.

The study informs applications requiring precise celestial pole coordinates.

Abstract

VLBI observations carried out by global networks provide the most accurate values of the precession-nutation angles determining the position of the celestial pole; as a rule, these results become available two to four weeks after the observations. Therefore, numerous applications, such as satellite navigation systems, operational determination of Universal Time, and space navigation, use predictions of the coordinates of the celestial pole. In connection with this, the accuracy of predictions of the precession- nutation angles based on observational data obtained over the last three years is analyzed for the first time, using three empiric nutation models---namely, those developed at the US Naval Observatory, the Paris Observatory, and the Pulkovo Observatory. This analysis shows that the last model has the best of accuracy in predicting the coordinates of the celestial pole. The rms error for a one-month prediction proposed by this model is below 100 microarcsecond.