Journal of geodesy . vol 89 n° 2Paru le : 01/02/2015 |
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Ajouter le résultat dans votre panierGravity field processing with enhanced numerical precision for LL-SST missions / Ilias Daras in Journal of geodesy, vol 89 n° 2 (February 2015)
[article]
Titre : Gravity field processing with enhanced numerical precision for LL-SST missions Type de document : Article/Communication Auteurs : Ilias Daras, Auteur ; Roland Pail, Auteur ; Michael Murböck, Auteur ; Wei Yong Yi, Auteur Année de publication : 2015 Article en page(s) : pp 99 - 110 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] capteur spatial
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] données GRACE
[Termes IGN] interféromètre au laser
[Termes IGN] orbitographie par GNSS
[Termes IGN] poursuite de satellite
[Termes IGN] précision absolue
[Termes IGN] test de performanceRésumé : (auteur) On their way to meet the augmenting demands of the Earth system user community concerning accuracies of temporal gravity field models, future gravity missions of low-low satellite-to-satellite tracking (LL-SST) type are expected to fly at optimized formations and make use of the latest technological achievements regarding the on-board sensor accuracies. Concerning the main measuring unit of an LL-SST type gravity mission, the inter-satellite measuring instrument, a much more precise interferometric laser ranging system is planned to succeed the K-band ranging system used by the Gravity Recovery and Climate Experiment (GRACE) mission. This study focuses on investigations concerning the potential performance of new generation sensors such as the laser interferometer within the gravity field processing chain. The sufficiency of current gravity field processing accuracies is tested against the new sensor requirements, via full-scale closed-loop numerical simulations of a GRACE Follow-On configuration scenario. Each part of the processing is validated separately with special emphasis on numerical errors and their impact on gravity field solutions. It is demonstrated that gravity field processing with double precision may be a limiting factor for taking full advantage of the laser interferometer’s accuracy. Instead, a hybrid processing scheme of enhanced precision is introduced, which uses double and quadruple precision in different parts of the processing chain, leading to system accuracies of only 17 nm in terms of geoid height reconstruction errors. Simulation results demonstrate the ability of enhanced precision processing to minimize the processing errors and thus exploit the full precision of a laser interferometer, when at the same time the computational times are kept within reasonable levels. Numéro de notice : A2015-331 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0764-2 Date de publication en ligne : 18/10/2014 En ligne : https://doi.org/10.1007/s00190-014-0764-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76656
in Journal of geodesy > vol 89 n° 2 (February 2015) . - pp 99 - 110[article]Assimilation of GRACE-derived oceanic mass distributions with a global ocean circulation model / J. Saynisch in Journal of geodesy, vol 89 n° 2 (February 2015)
[article]
Titre : Assimilation of GRACE-derived oceanic mass distributions with a global ocean circulation model Type de document : Article/Communication Auteurs : J. Saynisch, Auteur ; I. Bergmann–Wolf, Auteur ; M. Thomas, Auteur Année de publication : 2015 Article en page(s) : pp 121 - 139 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] anomalie de pesanteur
[Termes IGN] assimilation des données
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] correction atmosphérique
[Termes IGN] données GRACE
[Termes IGN] filtre de Kalman
[Termes IGN] masse d'eau
[Termes IGN] océan
[Termes IGN] océanographie spatialeRésumé : (auteur) To study the sub-seasonal distribution and generation of ocean mass anomalies, Gravity Recovery and Climate Experiment (GRACE) observations of daily and monthly resolution are assimilated into a global ocean circulation model with an ensemble-based Kalman-Filter technique. The satellite gravimetry observations are processed to become time-variable fields of ocean mass distribution. Error budgets for the observations and the ocean model’s initial state are estimated which contain the full covariance information. The consistency of the presented approach is demonstrated by increased agreement between GRACE observations and the ocean model. Furthermore, the simulations are compared with independent observations from 54 bottom pressure recorders. The assimilation improves the agreement to high-latitude recorders by up to 2 hPa. The improvements are caused by assimilation-induced changes in the atmospheric wind forcing, i.e., quantities not directly observed by GRACE. Finally, the use of the developed Kalman-Filter approach as a destriping filter to remove artificial noise contaminating the GRACE observations is presented Numéro de notice : A2015-332 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0766-0 Date de publication en ligne : 11/10/2014 En ligne : https://doi.org/10.1007/s00190-014-0766-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76657
in Journal of geodesy > vol 89 n° 2 (February 2015) . - pp 121 - 139[article]Consistent estimates of the dynamic figure parameters of the Earth / Wei Chen in Journal of geodesy, vol 89 n° 2 (February 2015)
[article]
Titre : Consistent estimates of the dynamic figure parameters of the Earth Type de document : Article/Communication Auteurs : Wei Chen, Auteur ; Jiancheng Li, Auteur ; Jim Ray, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 179 - 188 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] ellipsoïde (géodésie)
[Termes IGN] figure de la Terre
[Termes IGN] masse de la Terre
[Termes IGN] moment d'inertieRésumé : (auteur) The Earth’s dynamic figure parameters, namely the principal moments of inertia and dynamic ellipticities of the whole Earth, the fluid outer core and the solid inner core, are fundamental parameters for geodetic, geophysical and astronomical studies. This study aims to re-estimate the mass and the dynamic figure parameters of the Earth on the basis of some global gravity models (EGM2008, EIGEN-6C and EIGEN-6C2) recently released with unprecedented accuracies, as well as an improved value of the gravitational constant G recommended by the Committee on Data for Science and Technology (CODATA). With the potential coefficients of EGM2008, EIGEN-6C and EIGEN-6C2 rescaled to be consistent with the IAU (International Astronomical Union) and IAG (International Association of Geodesy) numerical standards, and other values of relevant parameters also being consistent with those numerical standards, we have obtained consistent estimates of the dynamic figure parameters of the stratified Earth using the theory described in Chen and Shen (J Geophys Res 115:B12419 2010). Our preferred principal moments of inertia for the whole Earth are A=(80,085.1±9.6)×1033 kg m2,B=(80,086.8±9.6)×1033 kg m2, and C=(80,349.0±9.6)×1033 kg m2, respectively, the accuracies being limited by the uncertainties of G and e (dynamic ellipticity of the whole Earth). Numéro de notice : A2015-333 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0768-y Date de publication en ligne : 29/10/2014 En ligne : https://doi.org/10.1007/s00190-014-0768-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76658
in Journal of geodesy > vol 89 n° 2 (February 2015) . - pp 179 - 188[article]