Estimación del periodo de la nutación libre del núcleo mediande un análsis VLBI

  1. Belda, Santiago 5
  2. Ferrándiz, José Manuel 5
  3. Escapa, Alberto 5
  4. Karbon, María 5
  5. Modiri, Sadegh 2
  6. Puente, Víctor 3
  7. Heinkelmann, Robert 6
  8. Martín Furones, Ángel 1
  9. Schuh, Harald 46
  1. 1 Universidad Politécnica de Valencia
    info
    Universidad Politécnica de Valencia

    Valencia, España

    ROR https://ror.org/01460j859

    Geographic location of the organization Universidad Politécnica de Valencia
  2. 2 Federal Agency for Cartography and Geodesy (Germany)
  3. 3 Instituto Geográfico Nacional
    info
    Instituto Geográfico Nacional

    Madrid, España

    ROR https://ror.org/03yycdv57

    Geographic location of the organization Instituto Geográfico Nacional
  4. 4 Technical University of Berlin
    info
    Technical University of Berlin

    Berlín, Alemania

    ROR https://ror.org/03v4gjf40

    Geographic location of the organization Technical University of Berlin
  5. 5 Universitat d'Alacant
    info
    Universitat d'Alacant

    Alicante, España

    ROR https://ror.org/05t8bcz72

    Geographic location of the organization Universitat d'Alacant
  6. 6 Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences
    info
    Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences

    Potsdam, Alemania

    ROR https://ror.org/04z8jg394

    Geographic location of the organization Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences
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Book:
10.ª Asamblea Hispano-Portuguesa de Geodesia y Geofísica: artículos

Publisher: Centro Nacional de Información Geográfica

ISBN: 978-84-416-7540-7

Year of publication: 2023

Pages: 54-58

Congress: Asamblea Hispano-Portuguesa de Geodesia y Geofísica (10. 2022. Toledo)

Type: Conference Paper

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Abstract

Currently, accurate observations of Celestial Pole Offsets (CPO) can only be obtained by the Very Long Baseline Interferometry (VLBI) technique. The CPO contain the free core nutation (FCN), trends and harmonics caused by deficiencies of the IAU 2006/2000A precession–nutation model and by geophysical excitations, as well as the noise of observations. FCN is a free mode of the Earth and, in principle, cannot be predicted. It can only be measured. In the joint Working Group "Improving Theories and Models of the Earth’s Rotation (ITMER)" of the IAU/IAG it was suggested that the model for the FCN needs to be improved. The accurate estimation of the free core nutation (FCN) period of about 430 days is a challenging prospect. But, is there any evidence that the period of the FCN varies with time? In 2000 it was unknown whether or not it did. If so, then this would complicate making a model of it. In this study, we tested different FCN periods using several subsets of the observed nutations derived from VLBI analysis with the purpose of finding the optimal configuration that provides the lowest residuals. That is why a large quantity of empirical FCN models were also estimated and tested with different sliding window lengths displaced by different time spans. This analysis could bring us significantly closer to meet the accuracy goals pursued by the Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG), i.e. 1 mm accuracy and 0.1 mm/year stability on global scales in terms of the ITRF defining parameters.

Funding information

Este estudio ha sido financiado por la Generalitat Valenciana (SEJIGENT/2021/001, PROMETEO/2021/030), la Unión Europea (NextGenerationEU ZAMBRANO 21-04) y el Ministerio de Ciencia e Innovación (PID2020-119383GB-I00, MCIN/AEI/10.13039/501100011033/).

Funders

Data source: Dialnet