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Self-consistent determination of the Earth’s GM, geocenter motion and figure axis orientation / Alexandre Couhert in Journal of geodesy, vol 94 n° 12 (December 2020)  

Public [article]  inJournal of geodesy > vol 94 n° 12 (December 2020) . - n° 113 Titre : Self-consistent determination of the Earth’s GM, geocenter motion and figure axis orientation Type de document : Article/Communication Auteurs : Alexandre Couhert, Auteur ; Christian Bizouard, Auteur ; F. Mercier, Auteur ; Kristel Chanard , Auteur ; Marianne Greff-Lefftz, Auteur ; Pierre Exertier, Auteur Année de publication : 2020 Projets : 1-Pas de projet / Article en page(s) : n° 113 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] données Ajisai [Termes IGN] données Jason [Termes IGN] données Lageos [Termes IGN] données LARES [Termes IGN] données Starlette [Termes IGN] données Stella [Termes IGN] données TLS (télémétrie) [Termes IGN] erreur de modèle [Termes IGN] harmonique sphérique [Termes IGN] incertitude géométrique [Termes IGN] mouvement du géocentre [Termes IGN] surface de la mer Résumé : (auteur) The very low-degree Earth’s gravity coefficients, associated with the largest-scale mass redistribution in the Earth’s fluid envelope (atmosphere, oceans and continental hydrology), are the most poorly known. In particular, the first three degree geopotential terms are important, as they relate to intrinsic Earth’s mass references: gravitational coefficient (GM) of the Earth (degree 0), geocenter motion (degree 1), Earth’s figure axis orientation (degree 2). This paper presents a self-consistent determination of these three properties of the Earth. The main objective is to deal with the remaining sources of altimetry satellite orbit uncertainties affecting the fundamental record of sea surface height measurements. The analysis identifies the modeling errors, which should be mitigated when estimating the geocenter coordinates from Satellite Laser Ranging (SLR) observations. The long-term behavior of the degree-0 and -2 spherical harmonics is also observed over the 34-year period 1984–2017 from the long-time history of satellite laser tracking to geodetic spherical satellites. From the analysis of the evolution of these two coefficients, constraints regarding the Earth’s rheology and uncertainties in the value of GM could be inferred. Overall, the influence of the orbit characteristics, SLR station ranging/position biases and satellite signature effects, measurement modeling errors (tropospheric corrections, non-tidal deformations) are also discussed. Numéro de notice : A2020-330 Affiliation des auteurs : UMR IPGP-Géod+Ext (2020- ) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-020-01450-z Date de publication en ligne : 18/11/2020 En ligne : https://doi.org/10.1007/s00190-020-01450-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96858 [article]

Center-of-mass corrections for sub-cm-precision laser-ranging targets: Starlette, Stella and LARES / Toshimichi Otsubo in Journal of geodesy, vol 89 n° 4 (April 2015)  

Public [article]  inJournal of geodesy > vol 89 n° 4 (April 2015) . - pp 303 - 312 Titre : Center-of-mass corrections for sub-cm-precision laser-ranging targets: Starlette, Stella and LARES Type de document : Article/Communication Auteurs : Toshimichi Otsubo, Auteur ; Robert A. Sherwood, Auteur ; Graham M. Appleby, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 303 - 312 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] données LARES [Termes IGN] données Starlette [Termes IGN] données Stella [Termes IGN] géodésie physique [Termes IGN] masse de la Terre [Termes IGN] précision des données [Termes IGN] télémétrie laser sur satellite Résumé : (auteur) To realize the full potential of satellite laser ranging for accurate geodesy, it is crucial that all systematic effects in the measurements are taken into account. This paper derives new values for the so-called center-of-mass corrections for three geodetic satellites that are regularly tracked and used in geodetic studies. Optical responses of the twin satellites, Starlette and Stella, and the LARES satellite are retrieved from kHz single-photon laser-ranging data observed at Herstmonceux and Potsdam. The detection timing inside single-photon systems, C-SPAD-based systems and photomultiplier-based systems is numerically simulated, and the center-of-mass corrections are derived to be in the range of 74 to 82 mm for Starlette and Stella, and 127–135 mm for LARES. The system dependence is below 1 cm, but should not be ignored for millimeter accuracy. The longtime standard center-of-mass correction 75 mm of Starlette and Stella is revealed to be too small for the current laser-ranging stations on average, which is considered to have resulted in a non-negligible systematic error in geodetic products. Numéro de notice : A2015-339 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0776-y Date de publication en ligne : 13/11/2014 En ligne : https://doi.org/10.1007/s00190-014-0776-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76708 [article]