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Using real polar ground gravimetry data to solve the GOCE polar gap problem in satellite-only gravity field recovery / Biao Lu in Journal of geodesy, Vol 94 n°3 (March 2020)
Titre : Using real polar ground gravimetry data to solve the GOCE polar gap problem in satellite-only gravity field recovery Type de document : Article/Communication Auteurs : Biao Lu, Auteur ; Christoph Förste, Auteur ; Franz Barthelmes, Auteur ; et al., Auteur Année de publication : 2020 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes descripteurs IGN] anomalie de pesanteur
[Termes descripteurs IGN] Antarctique
[Termes descripteurs IGN] Arctique
[Termes descripteurs IGN] champ de gravitation
[Termes descripteurs IGN] données GOCE
[Termes descripteurs IGN] données GRACE
[Termes descripteurs IGN] Earth Gravity Model 2008
[Termes descripteurs IGN] filtrage d'information
[Termes descripteurs IGN] levé gravimétrique
[Termes descripteurs IGN] modèle de géopotentiel
[Termes descripteurs IGN] zone polaireRésumé : (auteur) With the successful completion of European Space Agency (ESA)’s PolarGAP campaign, ground gravity data are now available for both polar regions. Therefore, it is now possible to solve the GOCE polar gap problem in satellite-only gravity field recovery by using additional polar ground gravity data instead of some regularization methods. However, ground gravimetry data need to be filtered to remove the short-wavelength information beyond a certain harmonic degree to avoid spectral leakage when inferring satellite-only gravity field models. For the Arctic, the ArcGP data set was successfully applied when inferring the high-resolution gravity field model EGM2008 which could be used for this filtering there. For Antarctica, a combination of latest airborne gravimetry data from ESA’s PolarGap campaign and some previous gravity data was recently published which was irregularly distributed in space and still had some small gaps within the GOCE south polar gap. Therefore, we proposed a point mass modeling method for this filtering which was similar to the way using EGM2008 for such filtering to the ground gravity data in the Arctic. Furthermore, a variance component estimation was applied to combine the normal equations from the different sources to build a global gravity field model called IGGT_R1C. Then, this model’s accuracy was evaluated by comparison with other gravity field models in terms of difference degree amplitudes, gravity anomaly differences as well as external checking by obit adjustment and gravity data in the GOCE polar gap areas. This gravity field model performed well globally according to these checking results; especially, the RMS of the residuals between the filtered gravity data and that calculated from IGGT_R1C was the smallest (2.6 mGal in the Arctic and 5.4 mGal in Antarctica) compared with that of the relevant satellite-only gravity field models, e.g., GOCO05s. Therefore, the disturbing impact of the GOCE polar data gap problem could be solved by adding the polar ground gravity data. Numéro de notice : A2020-155 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-020-01361-z date de publication en ligne : 25/02/2020 En ligne : https://doi.org/10.1007/s00190-020-01361-z Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94805
in Journal of geodesy > Vol 94 n°3 (March 2020)[article]
Titre : Assessment of the accuracy of global geodetic satellite laser ranging observations and estimated impact on ITRF scale: estimation of systematic errors in LAGEOS observations 1993–2014 Type de document : Article/Communication Auteurs : Graham Appleby, Auteur ; José Rodríguez, Auteur ; Zuheir Altamimi Année de publication : 2016 Article en page(s) : pp 1371 - 1388 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes descripteurs IGN] analyse diachronique
[Termes descripteurs IGN] champ de gravitation
[Termes descripteurs IGN] constante
[Termes descripteurs IGN] données Lageos
[Termes descripteurs IGN] données TLS (télémétrie)
[Termes descripteurs IGN] erreur systématique
[Termes descripteurs IGN] géocentre
[Termes descripteurs IGN] système de référence géodésiqueRésumé : (Auteur) Satellite laser ranging (SLR) to the geodetic satellites LAGEOS and LAGEOS-2 uniquely determines the origin of the terrestrial reference frame and, jointly with very long baseline interferometry, its scale. Given such a fundamental role in satellite geodesy, it is crucial that any systematic errors in either technique are at an absolute minimum as efforts continue to realise the reference frame at millimetre levels of accuracy to meet the present and future science requirements. Here, we examine the intrinsic accuracy of SLR measurements made by tracking stations of the International Laser Ranging Service using normal point observations of the two LAGEOS satellites in the period 1993 to 2014. The approach we investigate in this paper is to compute weekly reference frame solutions solving for satellite initial state vectors, station coordinates and daily Earth orientation parameters, estimating along with these weekly average range errors for each and every one of the observing stations. Potential issues in any of the large number of SLR stations assumed to have been free of error in previous realisations of the ITRF may have been absorbed in the reference frame, primarily in station height. Likewise, systematic range errors estimated against a fixed frame that may itself suffer from accuracy issues will absorb network-wide problems into station-specific results. Our results suggest that in the past two decades, the scale of the ITRF derived from the SLR technique has been close to 0.7 ppb too small, due to systematic errors either or both in the range measurements and their treatment. We discuss these results in the context of preparations for ITRF2014 and additionally consider the impact of this work on the currently adopted value of the geocentric gravitational constant, GM. Numéro de notice : A2016-808 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0929-2 date de publication en ligne : 29/06/2016 En ligne : http://dx.doi.org/10.1007/s00190-016-0929-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82596
in Journal of geodesy > vol 90 n° 12 (December 2016) . - pp 1371 - 1388[article]
Titre : Drift mode accelerometry for spaceborne gravity measurements Type de document : Article/Communication Auteurs : John W. Conklin, Auteur Année de publication : 2015 Article en page(s) : pp 1053 - 1070 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes descripteurs IGN] accéléromètre
[Termes descripteurs IGN] capteur spatial
[Termes descripteurs IGN] champ de gravitation
[Termes descripteurs IGN] test de performance
[Termes descripteurs IGN] torsion géodésiqueRésumé : (auteur) A drift mode accelerometer is a precision instrument for spacecraft that overcomes much of the acceleration noise and readout dynamic range limitations of traditional electrostatic accelerometers. It has the potential of achieving acceleration noise performance similar to that of drag-free systems over a restricted frequency band without the need for external drag-free control or continuous spacecraft propulsion. Like traditional accelerometers, the drift mode accelerometer contains a high-density test mass surrounded by an electrode housing, which can control and sense all six degrees of freedom of the test mass. Unlike traditional accelerometers, the suspension system is operated with a low duty cycle so that the limiting suspension force noise only acts over brief, known time intervals, which can be neglected in the data analysis. The readout is performed using a laser interferometer which is immune to the dynamic range limitations of even the best voltage references typically used to determine the inertial acceleration of electrostatic accelerometers. The drift mode accelerometer is a novel offshoot of the like-named operational mode of the LISA Pathfinder spacecraft, in which its test mass suspension system is cycled on and off to estimate the acceleration noise associated with the front-end electronics. This paper presents the concept of a drift mode accelerometer, describes the operation of such a device, develops models for its performance with respect to non-drag-free satellite geodesy and gravitational wave missions, and discusses plans for testing the performance of a prototype sensor in the laboratory using torsion pendula. Numéro de notice : A2015-882 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern En ligne : http://link.springer.com/article/10.1007/s00190-015-0833-1/fulltext.html Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79421
in Journal of geodesy > vol 89 n° 11 (november 2015) . - pp 1053 - 1070[article]
Titre : Alternative validation method of satellite gradiometric data by integral transform of satellite altimetry data Type de document : Article/Communication Auteurs : Michal Šprlák, Auteur ; Eliška Hamáčková, Auteur ; Pavel Novák, Auteur Année de publication : 2015 Article en page(s) : pp 757 - 773 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes descripteurs IGN] altimétrie satellitaire par radar
[Termes descripteurs IGN] champ de gravitation
[Termes descripteurs IGN] données GOCE
[Termes descripteurs IGN] équation intégrale
[Termes descripteurs IGN] gradient de gravitation
[Termes descripteurs IGN] gradiométrie
[Termes descripteurs IGN] potentiel de pesanteur terrestreRésumé : (auteur) Integral transforms of the disturbing gravitational potential derived from satellite altimetry onto satellite gradiometric data are formulated, investigated and applied in this article. First, corresponding differential operators, that relate the disturbing gravitational potential to the six components of the disturbing gradiometric tensor in the spherical local north-oriented frame, are applied to the spherical Abel-Poisson integral equation. This yields six new integral equations for which respective kernel functions are given in both spectral and spatial forms. Second, truncation error formulas for each of the integral transforms are provided in the spectral form. Also expressions for the corresponding truncation error coefficients are derived. Third, practical estimators for evaluation of the disturbing gravitational gradients are formulated, and their correctness and expected accuracy are investigated. Finally, the practical estimators are applied for validation of a sample of the gradiometric data provided by the GOCE satellite mission. Obtained results demonstrate applicability of the new apparatus as an alternative validation method of the satellite gravitational gradients. Numéro de notice : A2015-375 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern En ligne : http://link.springer.com/article/10.1007/s00190-015-0813-5/fulltext.html Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76853
in Journal of geodesy > vol 89 n° 8 (August 2015) . - pp 757 - 773[article]
Titre : Empirical model of the gravitational field generated by the oceanic lithosphere Type de document : Article/Communication Auteurs : Robert Tenzer, Auteur ; W. Chen, Auteur ; Zhourun Ye, Auteur Année de publication : 2015 Article en page(s) : pp 72 - 82 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes descripteurs IGN] champ de gravitation
[Termes descripteurs IGN] champ de pesanteur terrestre
[Termes descripteurs IGN] harmonique sphérique
[Termes descripteurs IGN] isostasie
[Termes descripteurs IGN] lithosphère
[Termes descripteurs IGN] modèle empirique
[Termes descripteurs IGN] océanRésumé : (auteur) We present an empirical model of the gravitational field generated by the oceanic lithosphere computed over the world’s oceans with a spectral resolution complete to a spherical harmonic degree of 180. This gravity model is compiled based on applying methods for a spherical harmonic analysis and synthesis of the global gravity and crustal structure models. The in situ seawater densities and the density samples from ocean-floor drilling sites are utilized in the gravimetric forward modeling of bathymetry and marine sediments. The gravitational signal attributed to the oceanic lithosphere density structure is described empirically in terms of the ocean-floor age and depth. The former is explained by the increasing density with age due to conductive cooling of the oceanic lithosphere. The latter describes the gravitational signature of thermal lithospheric contraction, which is isostatically compensated by ocean deepening. The long-wavelength gravity spectrum reflects mainly the compositional and thermal structures within the sub-lithospheric mantle. We demonstrate that this empirical gravity model reproduces realistically most of the long-to-medium wavelength features of the actual gravity field, except for some systematic discrepancies, especially along continental slopes and large sedimentary accumulations, which cannot be described accurately by applied empirical models. Numéro de notice : A2015-296 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern En ligne : http://www.sciencedirect.com/science/article/pii/S0273117714005882 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76456
in Advances in space research > vol 55 n° 1 [01/01/2015] . - pp 72 - 82[article]PermalinkPermalinkInverse Probleme bei der Gravitationsfelsbestimmung mittels SST- und SGG-Satellitenmissionen Darstellungen / J. Kusche (2002)
PermalinkPermalinkPermalinkPermalinkPermalinkDas Projekt "Satelliten- und Inertialgeodäsie" der Bayerischen Kommission für die Internationale Erdmessung Berichtskolloquium anläßlich der Begutachtung der Kommission im Rahmen des Akademienprogramms am 2. und 3. Juli 1990 / Rudolf Sigl (1991)
PermalinkPermalinkVingt ans de recherche en géodésie spatiale, Actes du colloque scientifique du GRGS / Martine Feissel-Vernier (1991)
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