G022-05
Improved precession-nutation models: A first assessment

Wednesday, 16 December 2020: 05:54
Virtual
Jose M. Ferrandiz1, Alberto Escapa2, Santiago Belda-Palazón3, Tomás Baenas4, Sadegh Modiri5, Robert Heinkelmann6 and Harald Schuh5, (1)University of Alicante, Alicante, Spain, (2)University of León, Aerospace Enginering, León, Spain, (3)University of Valencia, Image Processing Laboratory (IPL) - Laboratory of Earth Observation (LEO), Valencia, Spain, (4)University Centre of Defence at the Spanish Air Force Academy, Santiago de la Ribera, Spain, (5)GFZ German Research Centre for Geosciences, Space Geodetic Techniques, Potsdam, Germany, (6)Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany
Recorded Presentation
Abstract:
The improvement of the modelling and predictions of the Earth orientation parameters (EOP) was encouraged by Resolution 5 of the International Association of Geodesy (IAG) adopted in 2019. The last Unified Analysis Workshop of GGOS/IERS held in October 2019 recommended the development of improved precession-nutation models to be prioritized among the tasks of the current IAU/IAG Joint Working Group on Improving theories and models of the Earth’s rotation (JWG ITMER).

This presentation is concerned with the preliminary assessment of new semi-empirical/semi-theorical precession-nutation models developed by the authors from well-known VLBI solutions. The celestial pole offsets (CPO) corrections are derived in usual form as sum of polynomial and harmonic components, focusing on the accuracy attainable either with or without the concourse of specially fitted free core nutation (FCN) models. In the studied cases the unexplained variance can be brought below 80-90 micro arcseconds, so closer than before to the GGOS accuracy target.

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