This paper investigates the practical use of the nonrotating origin (NRO) (Guinot 1979) for estim... more This paper investigates the practical use of the nonrotating origin (NRO) (Guinot 1979) for estimating the Earth Rotation Parameters from VLBI data, which is based on the rotational transformation between the geocentric celestial and terrestrial frames as previously derived by Capitaine (1990). Numerical checks of consistency show that the transformation referred to the NRO is equivalent to the classical one referred to the equinox and considering the complete “equation of the equinoxes” (Aoki & Kinoshita 1983). The paper contains the expressions for the partial derivatives of the VLBI geometric delay to be used for the adjustment of the pole coordinates, UT1 and deficiencies in the two celestial coordinates of the Celestial Ephemeris Pole (CEP) in the multiparameters fits to VLBI data. The use of the NRO is shown to simplify the estimates of these parameters and to free the estimated UT1 parameter from the model for precession and nutation.
ABSTRACT The Journees 2011, with the sub-title "Earth rotation, reference systems and ce... more ABSTRACT The Journees 2011, with the sub-title "Earth rotation, reference systems and celestial mechanics: Synergies of geodesy and astronomy", were organized at Bundesamt fur Eich- und Vermessungswesen (BEV), Vienna, from 19 to 21 September 2011. They were the 21st meeting in the Journees conference series, which provide an international forum for advanced discussion in the fields of space and time reference systems, Earth rotation, dynamics of the solar system, astrometry and time. The Journees 2011 were focused on issues related to recent developments in fundamental astronomy, time and relativity, plans for the next generation of space-time reference systems, astronomical space and time reference systems, Earth rotation and global geodynamics, celestial mechanics of solar system bodies, space observations and dedicated missions for geodesy and astronomy. There were presentations and discussions related to the Division 1 IAU Working Groups and Division 1 commissions.
Report of the IAU WGAS (Working Group on Astronomical Standards) sub - working group on relativit... more Report of the IAU WGAS (Working Group on Astronomical Standards) sub - working group on relativity in celestial mechanics and astrometry (RCMA SWG).
Analysis of Lunar Laser ranging observations allows to determine a number of parameters related t... more Analysis of Lunar Laser ranging observations allows to determine a number of parameters related to the dynamics of the Earth-Moon system. It also contributes to the determination of the Earth Orientation Parameters (EOP) such as precession-nutation, polar motion and UT1. Here, we focus on the determination of the precession-nutation corrections DX , DY to the conventional model for the coordinates of the CIP (Celestial Intermediate Pole) in the GCRS (Geocentric Celestial Reference System), which are used in this study, instead of the classical parameters determined in previous works.
We analyze the impact of the installation of a lunar laser ranging device on the NTT 3.6m ESO tel... more We analyze the impact of the installation of a lunar laser ranging device on the NTT 3.6m ESO telescope. With such an instrument, the scientific communities of fundamental physics and solar system formation will highly benefit of the only LLR station in the Southern Hemisphere. The quality of the NTT 3.6 meter telescope will also greatly complement the LLR 3.5 meter Apache Point telescope (3.5 m) instrument in the Northern Hemisphere (USA) which is the best instrument for tracking the Moon since 2006. Finally, we also consider the technical characteristics of such installation including the observational constraints.
This paper investigates the practical use of the nonrotating origin (NRO) (Guinot 1979) for estim... more This paper investigates the practical use of the nonrotating origin (NRO) (Guinot 1979) for estimating the Earth Rotation Parameters from VLBI data, which is based on the rotational transformation between the geocentric celestial and terrestrial frames as previously derived by Capitaine (1990). Numerical checks of consistency show that the transformation referred to the NRO is equivalent to the classical one referred to the equinox and considering the complete “equation of the equinoxes” (Aoki & Kinoshita 1983). The paper contains the expressions for the partial derivatives of the VLBI geometric delay to be used for the adjustment of the pole coordinates, UT1 and deficiencies in the two celestial coordinates of the Celestial Ephemeris Pole (CEP) in the multiparameters fits to VLBI data. The use of the NRO is shown to simplify the estimates of these parameters and to free the estimated UT1 parameter from the model for precession and nutation.
ABSTRACT The Journees 2011, with the sub-title "Earth rotation, reference systems and ce... more ABSTRACT The Journees 2011, with the sub-title "Earth rotation, reference systems and celestial mechanics: Synergies of geodesy and astronomy", were organized at Bundesamt fur Eich- und Vermessungswesen (BEV), Vienna, from 19 to 21 September 2011. They were the 21st meeting in the Journees conference series, which provide an international forum for advanced discussion in the fields of space and time reference systems, Earth rotation, dynamics of the solar system, astrometry and time. The Journees 2011 were focused on issues related to recent developments in fundamental astronomy, time and relativity, plans for the next generation of space-time reference systems, astronomical space and time reference systems, Earth rotation and global geodynamics, celestial mechanics of solar system bodies, space observations and dedicated missions for geodesy and astronomy. There were presentations and discussions related to the Division 1 IAU Working Groups and Division 1 commissions.
Report of the IAU WGAS (Working Group on Astronomical Standards) sub - working group on relativit... more Report of the IAU WGAS (Working Group on Astronomical Standards) sub - working group on relativity in celestial mechanics and astrometry (RCMA SWG).
Analysis of Lunar Laser ranging observations allows to determine a number of parameters related t... more Analysis of Lunar Laser ranging observations allows to determine a number of parameters related to the dynamics of the Earth-Moon system. It also contributes to the determination of the Earth Orientation Parameters (EOP) such as precession-nutation, polar motion and UT1. Here, we focus on the determination of the precession-nutation corrections DX , DY to the conventional model for the coordinates of the CIP (Celestial Intermediate Pole) in the GCRS (Geocentric Celestial Reference System), which are used in this study, instead of the classical parameters determined in previous works.
We analyze the impact of the installation of a lunar laser ranging device on the NTT 3.6m ESO tel... more We analyze the impact of the installation of a lunar laser ranging device on the NTT 3.6m ESO telescope. With such an instrument, the scientific communities of fundamental physics and solar system formation will highly benefit of the only LLR station in the Southern Hemisphere. The quality of the NTT 3.6 meter telescope will also greatly complement the LLR 3.5 meter Apache Point telescope (3.5 m) instrument in the Northern Hemisphere (USA) which is the best instrument for tracking the Moon since 2006. Finally, we also consider the technical characteristics of such installation including the observational constraints.
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