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Empirical model of the gravitational field generated by the oceanic lithosphere / Robert Tenzer in Advances in space research, vol 55 n° 1 ([01/01/2015])
[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 IGN] champ de gravitation
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] harmonique sphérique
[Termes IGN] isostasie
[Termes IGN] lithosphère
[Termes IGN] modèle empirique
[Termes 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 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2014.09.023 En ligne : https://doi.org/10.1016/j.asr.2014.09.023 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]Reducing the draconitic errors in GNSS geodetic products / C.J. Rodriguez-Solano in Journal of geodesy, vol 88 n° 6 (June 2014)
[article]
Titre : Reducing the draconitic errors in GNSS geodetic products Type de document : Article/Communication Auteurs : C.J. Rodriguez-Solano, Auteur ; Urs Hugentobler, Auteur ; et al., Auteur Année de publication : 2014 Article en page(s) : pp 559 - 574 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] éclipse (astronomie)
[Termes IGN] harmonique sphérique
[Termes IGN] lacet
[Termes IGN] positionnement par GNSS
[Termes IGN] rayonnement solaireRésumé : (Auteur) Systematic errors at harmonics of the GPS draconitic year have been found in diverse GPS-derived geodetic products like the geocenter Z -component, station coordinates, Y -pole rate and orbits (i.e. orbit overlaps). The GPS draconitic year is the repeat period of the GPS constellation w.r.t. the Sun which is about 351 days. Different error sources have been proposed which could generate these spurious signals at the draconitic harmonics. In this study, we focus on one of these error sources, namely the radiation pressure orbit modeling deficiencies. For this purpose, three GPS+GLONASS solutions of 8 years (2004–2011) were computed which differ only in the solar radiation pressure (SRP) and satellite attitude models. The models employed in the solutions are: (1) the CODE (5-parameter) radiation pressure model widely used within the International GNSS Service community, (2) the adjustable box-wing model for SRP impacting GPS (and GLONASS) satellites, and (3) the adjustable box-wing model upgraded to use non-nominal yaw attitude, specially for satellites in eclipse seasons. When comparing the first solution with the third one we achieved the following in the GNSS geodetic products. Orbits: the draconitic errors in the orbit overlaps are reduced for the GPS satellites in all the harmonics on average 46, 38 and 57 % for the radial, along-track and cross-track components, while for GLONASS satellites they are mainly reduced in the cross-track component by 39 %. Geocenter Z -component: all the odd draconitic harmonics found when the CODE model is used show a very important reduction (almost disappearing with a 92 % average reduction) with the new radiation pressure models. Earth orientation parameters: the draconitic errors are reduced for the X -pole rate and especially for the Y -pole rate by 24 and 50 % respectively. Station coordinates: all the draconitic harmonics (except the 2nd harmonic in the North component) are reduced in the North, East and Height components, with average reductions of 41, 39 and 35 % respectively. This shows, that part of the draconitic errors currently found in GNSS geodetic products are definitely induced by the CODE radiation pressure orbit modeling deficiencies Numéro de notice : A2014-287 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0704-1 Date de publication en ligne : 07/03/2014 En ligne : https://doi.org/10.1007/s00190-014-0704-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33190
in Journal of geodesy > vol 88 n° 6 (June 2014) . - pp 559 - 574[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2014061 SL Revue Centre de documentation Revues en salle Disponible Comparison among three harmonic analysis techniques on the sphere and the ellipsoid / Hussein Abd-Elmotaal in Journal of applied geodesy, vol 8 n° 1 (April 2014)
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Titre : Comparison among three harmonic analysis techniques on the sphere and the ellipsoid Type de document : Article/Communication Auteurs : Hussein Abd-Elmotaal, Auteur ; Kurt Seitz, Auteur ; Mostafa Abd-Elbaky, Auteur ; Bernhard Heck, Auteur Année de publication : 2014 Article en page(s) : pp 1 - 19 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse comparative
[Termes IGN] anomalie de pesanteur
[Termes IGN] Earth Gravity Model 2008
[Termes IGN] ellipsoïde (géodésie)
[Termes IGN] harmonique ellipsoïdale
[Termes IGN] harmonique sphérique
[Termes IGN] méthode des moindres carrés
[Termes IGN] transformation rapide de FourierRésumé : (Auteur) The paper presents a comparison among three different techniques for harmonic analysis on the sphere and the ellipsoid. The EGM2008 global geopotential model has been used up to degree and order 360 in order to create gravity anomaly fields on both the sphere and the ellipsoid as the function fields of the current investigation. Harmonic analysis has then been carried out to compute the dimensionless potential coeficients using the created function fields. Three different harmonic analysis techniques have been applied: the least-squares technique, the Fast Fourier Transform (FFT) technique and the Gauss-Legendre numerical integration technique. The computed coeficients in spherical harmonics have then been compared with EGM2008 (in the frequency domain) and the computed fields on the sphere and the ellipsoid have been compared with fields created by EGM2008 up to degree and order 360 (in the space domain) in order to estimate the accuracy of the three different harmonic analysis techniques used within the current investigation. The results proved that the least-squares technique gives the best accuracy both in frequency and space domain. The FFT technique provides quite good results in a very short cpu time. The Gauss-Legendre technique gives the worst results among the presented techniques, but still the residuals in the space domain are negligibly small. Numéro de notice : A2014-270 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2013-0008 En ligne : http://www.degruyter.com/view/j/jag.2014.8.issue-1/jag-2013-0008/jag-2013-0008.x [...] Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33173
in Journal of applied geodesy > vol 8 n° 1 (April 2014) . - pp 1 - 19[article]Evaluation of the third- and fourth-generation GOCE Earth gravity field models with Australian terrestrial gravity data in spherical harmonics / Moritz Rexer in Journal of geodesy, vol 88 n° 4 (April 2014)
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Titre : Evaluation of the third- and fourth-generation GOCE Earth gravity field models with Australian terrestrial gravity data in spherical harmonics Type de document : Article/Communication Auteurs : Moritz Rexer, Auteur ; Christian Hirt, Auteur ; Roland Pail, Auteur ; Sten Claessens, Auteur Année de publication : 2014 Article en page(s) : pp 319 - 333 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] Australie
[Termes IGN] données géophysiques
[Termes IGN] données GOCE
[Termes IGN] évaluation des données
[Termes IGN] harmonique sphérique
[Termes IGN] levé gravimétriqueRésumé : (Auteur) In March 2013, the fourth generation of European Space Agency’s (ESA) global gravity field models, DIR4 (Bruinsma et al. in Proceedings of the ESA living planet symposium, 28 June–2 July, Bergen, ESA, Publication SP-686, 2010b) and TIM4 (Migliaccio et al. in Proceedings of the ESA living planet symposium, 28 June–2 July, Bergen, ESA, Publication SP-686, 2010), generated from the Gravity field and steady-state Ocean Circulation Explorer (GOCE) gravity observation satellite was released. We evaluate the models using an independent ground truth data set of gravity anomalies over Australia. Combined with Gravity Recovery and Climate Experiment (GRACE) satellite gravity, a new gravity model is obtained that is used to perform comparisons with GOCE models in spherical harmonics. Over Australia, the new gravity model proves to have significantly higher accuracy in the degrees below 120 as compared to EGM2008 and seems to be at least comparable to the accuracy of this model between degree 150 and degree 260. Comparisons in terms of residual quasi-geoid heights, gravity disturbances, and radial gravity gradients evaluated on the ellipsoid and at approximate GOCE mean satellite altitude ( h=250 km) show both fourth generation models to improve significantly w.r.t. their predecessors. Relatively, we find a root-mean-square improvement of 39 % for the DIR4 and 23 % for TIM4 over the respective third release models at a spatial scale of 100 km (degree 200). In terms of absolute errors, TIM4 is found to perform slightly better in the bands from degree 120 up to degree 160 and DIR4 is found to perform slightly better than TIM4 from degree 170 up to degree 250. Our analyses cannot confirm the DIR4 formal error of 1 cm geoid height (0.35 mGal in terms of gravity) at degree 200. The formal errors of TIM4, with 3.2 cm geoid height (0.9 mGal in terms of gravity) at degree 200, seem to be realistic. Due to combination with GRACE and SLR data, the DIR models, at satellite altitude, clearly show lower RMS values compared to TIM models in the long wavelength part of the spectrum (below degree and order 120). Our study shows different spectral sensitivity of different functionals at ground level and at GOCE satellite altitude and establishes the link among these findings and the Meissl scheme (Rummel and van Gelderen in Manusrcipta Geodaetica 20:379–385, 1995). Numéro de notice : A2014-158 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-013-0680-x Date de publication en ligne : 14/12/2013 En ligne : https://doi.org/10.1007/s00190-013-0680-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33063
in Journal of geodesy > vol 88 n° 4 (April 2014) . - pp 319 - 333[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2014041 SL Revue Centre de documentation Revues en salle Disponible Comparing seven candidate mission configurations for temporal gravity field retrieval through full-scale numerical simulation / Basem Elsaka in Journal of geodesy, vol 88 n° 1 (January 2014)
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Titre : Comparing seven candidate mission configurations for temporal gravity field retrieval through full-scale numerical simulation Type de document : Article/Communication Auteurs : Basem Elsaka, Auteur ; Jean-Claude Raimondo, Auteur ; Phillip Brieden, Auteur ; et al., Auteur Année de publication : 2014 Article en page(s) : pp 31 - 43 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse comparative
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] données GRACE
[Termes IGN] données multitemporelles
[Termes IGN] harmonique sphérique
[Termes IGN] mission spatiale
[Termes IGN] simulation numériqueRésumé : (Auteur) The goal of this contribution is to focus on improving the quality of gravity field models in the form of spherical harmonic representation via alternative configuration scenarios applied in future gravimetric satellite missions. We performed full-scale simulations of various mission scenarios within the frame work of the German joint research project “Concepts for future gravity field satellite missions” as part of the Geotechnologies Program, funded by the German Federal Ministry of Education and Research and the German Research Foundation. In contrast to most previous simulation studies including our own previous work, we extended the simulated time span from one to three consecutive months to improve the robustness of the assessed performance. New is that we performed simulations for seven dedicated satellite configurations in addition to the GRACE scenario, serving as a reference baseline. These scenarios include a “GRACE Follow-on” mission (with some modifications to the currently implemented GRACE-FO mission), and an in-line “Bender” mission, in addition to five mission scenarios that include additional cross-track and radial information. Our results clearly confirm the benefit of radial and cross-track measurement information compared to the GRACE along-track observable: the gravity fields recovered from the related alternative mission scenarios are superior in terms of error level and error isotropy. In fact, one of our main findings is that although the noise levels achievable with the particular configurations do vary between the simulated months, their order of performance remains the same. Our findings show also that the advanced pendulums provide the best performance of the investigated single formations, however an accuracy reduced by about 2–4 times in the important long-wavelength part of the spectrum (for spherical harmonic degrees Numéro de notice : A2014-101 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-013-0665-9 Date de publication en ligne : 09/11/2013 En ligne : https://doi.org/10.1007/s00190-013-0665-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33006
in Journal of geodesy > vol 88 n° 1 (January 2014) . - pp 31 - 43[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2014011 SL Revue Centre de documentation Revues en salle Disponible Prise en compte des déformations co- et post-sismiques pour la détermination d'un repère de référence / Daphné Lercier (2014)PermalinkAnalytical error analysis for satellite gravity field determination based on two-dimensional Fourier method / Lin Cai in Journal of geodesy, vol 87 n° 5 (May 2013)PermalinkEstimation of mass change trends in the Earth’s system on the basis of GRACE satellite data, with application to Greenland / C. Siemes in Journal of geodesy, vol 87 n° 1 (January 2013)PermalinkGlobal height system unification with GOCE: a simulation study on the indirect bias term in the GBVP approach / C. Gerlach in Journal of geodesy, vol 87 n° 1 (January 2013)PermalinkFourier-series representation and projection of spherical harmonic functions / H. Cheong in Journal of geodesy, vol 86 n° 11 (November 2012)PermalinkReducing errors in the GRACE gravity solutions using regularization / H. Save in Journal of geodesy, vol 86 n° 9 (September 2012)PermalinkBasic equations for constructing geopotential models from the gravitational potential derivatives of the first and second orders in the terrestrial reference frame / M. Petrovskaya in Journal of geodesy, vol 86 n° 7 (July 2012)PermalinkITRF2008 contribution to glacial isostatic adjustment and recent ice melting assessment / Laurent Métivier in Geophysical research letters, vol 39 n° 1 (January 2012)PermalinkValidation of GOCE gravity field models by means of orbit residuals and geoid comparisons / Thomas Gruber in Journal of geodesy, vol 85 n° 11 (November /2011)PermalinkWavelet modelling of the gravity field by domain decomposition methods: an example over Japan / Isabelle Panet in Geophysical journal international, vol 184 n° 1 (January 2011)PermalinkConstruction of spherical harmonic series for the potential derivatives of arbitrary orders in the geocentric Earth-fixed reference frame / M. Petrovskaya in Journal of geodesy, vol 84 n° 3 (March 2010)PermalinkPrediction of vertical deflections from high-degree spherical harmonic synthesis and residual terrain model data / C. Hirt in Journal of geodesy, vol 84 n° 3 (March 2010)PermalinkAssessment of a numerical method for computing the spherical harmonic coefficients of the gravitational potential of a constant density polyhedron / Olivier Jamet (2010)PermalinkWavelet modeling of the gravity field over Japan / Isabelle Panet in Bulletin of the Geographical survey institute, vol 57 (December 2009)PermalinkEfficient propagation of error covariance matrices of gravitational models: application to GRACE and GOCE / Georges Balmino in Journal of geodesy, vol 83 n° 10 (October 2009)PermalinkLocal multi-polar expansions in potential field modeling / B. Minchev in Earth, Planets and Space, vol 61 n° 10 (October 2009)PermalinkRecursive algorithms for the computation of the potential harmonic coefficients of a constant density polyhedron / Dimitrios Tsoulis in Journal of geodesy, vol 83 n° 10 (October 2009)PermalinkOptima multi-step collocation: application to the space-wise approach for GOCE data analysis / M. Reguzzoni in Journal of geodesy, vol 83 n° 1 (January 2009)PermalinkPermalinkA study reference frame consistency in recent Earth gravitational models / Christopher Kotsakis in Journal of geodesy, vol 83 n° 1 (January 2009)Permalink