Measurement of Earth's Nutation by VLBI: Direct Estimates from VLBI Delays and a Discussion on the Error

• Main Authors: Lambert, S., Nurul-Huda, I., Ziegler, Y., Richard, J.-Y., Liu, N., Gattano, C., Rosat, S., Bizouard, C.
• Other Authors: Centre National de la Recherche Scientifique (CNRS), M2A 2019, Laboratoire d'Astrophysique de Bordeaux Pessac (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Dynamique globale et déformation active (IPGS) (IPGS-DGDA), Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2018
• Subjects: [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]; Norway; Svalbard
• Online Access: https://hal.archives-ouvertes.fr/hal-02278150

International audience Accurate measurements of the Earth nutation by VLBI provide insights into the deformability of and the coupling mechanisms at the core-mantle and core-inner core boundaries. We propose here to adjust nutation amplitudes directly to VLBI delays, as opposed to the traditional method consisting of fitting nutation amplitudes to time-domain nutation series. However, the complexity of the VLBI analysis chain makes the formal error on the parameters somehow obscure and disconnected from a realistic error based on, e.g., empirical tests of robustness and errors on models. In this work, we address some striking differences between formal and empirical errors.