Analysis of the impact of enhanced predicted EOP on satellite orbit prediction

Abstract

Earth Orientation Parameters (EOP) constitute the set of parameters that describe the rotation of the Earth with respect to an inertial reference frame. Apart from proper force modelling, EOP are also needed in orbit prediction to calculate the position and velocity of satellites in space. The accuracy of EOP prediction is essential for orbit determination since any error in its computation will propagate to the predicted state vector of the satellite. The magnitude of the impact of EOP prediction errors depends on the type of orbit and the time interval over which the predictions are made. These EOP prediction inaccuracies can lead to significant position errors as small errors in the EOP accumulate rapidly, thus resulting in larger deviations from the nominal satellite position. Therefore, this effect can be significant and become a concern for applications requiring high precision, such as positioning. In this contribution, we present numerical results of the discrepancies in the GNSS orbit prediction found when propagating the satellite orbits employing different time series of EOP predicted values. We show a comparison and assessment of the EOP values obtained by different prediction methods used in the 2nd Earth Orientation Parameters Prediction Comparison Campaign (2nd EOP PCC), aiming to study the validation of those EOP that yield the most accurate results in the GNSS orbit prediction.