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SHPTS: towards a new method for generating precise global ionospheric TEC map based on spherical harmonic and generalized trigonometric series functions / Zishen Li in Journal of geodesy, vol 89 n° 4 (April 2015)
[article]
Titre : SHPTS: towards a new method for generating precise global ionospheric TEC map based on spherical harmonic and generalized trigonometric series functions Type de document : Article/Communication Auteurs : Zishen Li, Auteur ; Yunbin Yuan, Auteur ; Ningbo Wang, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 333 - 345 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] données DORIS
[Termes IGN] données Topex-Poseidon
[Termes IGN] fonction harmonique
[Termes IGN] harmonique sphérique
[Termes IGN] modèle ionosphérique
[Termes IGN] série de Fourier
[Termes IGN] signal GNSS
[Termes IGN] teneur totale en électrons
[Termes IGN] trigonométrie sphériqueRésumé : (auteur) To take maximum advantage of the increasing Global Navigation Satellite Systems (GNSS) data to improve the accuracy and resolution of global ionospheric TEC map (GIM), an approach, named Spherical Harmonic plus generalized Trigonometric Series functions (SHPTS), is proposed by integrating the spherical harmonic and the generalized trigonometric series functions on global and local scales, respectively. The SHPTS-based GIM from January 1st, 2001 to December 31st, 2011 (about one solar cycle) is validated by the ionospheric TEC from raw global GPS data, the GIM released by the current Ionospheric Associate Analysis Center (IAAC), the TOPEX/Poseidon satellite and the DORIS. The present results show that the SHPTS-based GIM over the area where no real data are available has the same accuracy level (approximately 2–6 TECu) to that released by the current IAAC. However, the ionospheric TEC in the SHPTS-based GIM over the area covered by real data is more accurate (approximately 1.5 TECu) than that of the GIM (approximately 3.0 TECu) released by the current IAAC. The external accuracy of the SHPTS-based GIM validated by the TOPEX/Poseidon and DORIS is approximately 2.5–5.5 and 1.5–4.5 TECu, respectively. In particular, the SHPTS-based GIM is the best or almost the best ranked, along with those of JPL and UPC, when they are compared with TOPEX/Poseidon measurements, and the best (in addition to UPC) when they are validated with DORIS data. With the increase in the number of GNSS satellites and contributing stations, the performance of the SHPTS-based GIM can be further improved. The SHPTS-based GIM routinely calculated using global GPS, GLONASS and BDS data will be found at the website http://www.gipp.org.cn. Numéro de notice : A2015-341 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0778-9 Date de publication en ligne : 02/12/2014 En ligne : https://doi.org/10.1007/s00190-014-0778-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76710
in Journal of geodesy > vol 89 n° 4 (April 2015) . - pp 333 - 345[article]
[article]
Titre : La mission Rosetta et le calcul de gravité Type de document : Article/Communication Auteurs : Julien Laurent-Varin, Auteur ; Eric Jurado, Auteur Année de publication : 2015 Article en page(s) : pp 17 - 22 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] centre de gravité
[Termes IGN] champ gravifique
[Termes IGN] harmonique sphérique
[Termes IGN] mission spatiale
[Termes IGN] trajectoire (véhicule non spatial)Résumé : (Auteur) La mission Rosetta a été, et est, un succès historique pour les activité spatiales européennes. Pour accomplir cet exploit, une des étapes nécessaires était la construction du champ de gravité de ce corps. Ce pré-requis indispensable au calcul de trajectoire, a permis de mettre en œuvre le processus de sélection du site d'atterrissage de Philae. Cet article décrit ce processus de sélection ainsi que les méthodes et algorithmes appliqués dans le calcul du champ de gravité de la comète Churyumov-Gerasimenko 67P. Numéro de notice : A2015-113 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75635
in XYZ > n° 142 (mars - mai 2015) . - pp 17 - 22[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 112-2015011 RAB Revue Centre de documentation En réserve L003 Disponible Documents numériques
en open access
La mission Rosetta et le calcul de gravité - pdf éditeurAdobe Acrobat PDF 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])
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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]Extracting tidal frequencies using multivariate harmonic analysis of sea level height time series / Ali Reza Amiri-Simkooei in Journal of geodesy, vol 88 n° 10 (October 2014)
[article]
Titre : Extracting tidal frequencies using multivariate harmonic analysis of sea level height time series Type de document : Article/Communication Auteurs : Ali Reza Amiri-Simkooei, Auteur ; S. Zaminpardaz, Auteur ; M. Sharifi, Auteur Année de publication : 2014 Article en page(s) : pp 975 - 988 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] données marégraphiques
[Termes IGN] fonction harmonique
[Termes IGN] marée océanique
[Termes IGN] niveau de la mer
[Termes IGN] série temporelleRésumé : (Auteur) This contribution is seen as a first attempt to extract the tidal frequencies using a multivariate spectral analysis method applied to multiple time series of tide-gauge records. The existing methods are either physics-based in which the ephemeris of Moon, Sun and other planets are used, or are observation-based in which univariate analysis methods—Fourier and wavelet for instance—are applied to tidal observations. The existence of many long tide-gauge records around the world allows one to use tidal observations and extract the main tidal constituents for which efficient multivariate methods are to be developed. This contribution applies the multivariate least-squares harmonic estimation (LS-HE) to the tidal time series of the UK tide-gauge stations. The first 413 harmonics of the tidal constituents and their nonlinear components are provided using the multivariate LS-HE. A few observations of the research are highlighted: (1) the multivariate analysis takes information of multiple time series into account in an optimal least-squares sense, and thus the tidal frequencies have higher detection power compared to the univariate analysis. (2) Dominant tidal frequencies range from the long-term signals to the sixth-diurnal species interval. Higher frequencies have negligible effects. (3) The most important tidal constituents (the first 50 frequencies) ordered from their amplitudes range from 212 cm (M2) to 1 cm (OQ2) for the data set considered. There are signals in this list that are not available in the 145 main tidal frequencies of the literature. (4) Tide predictions using different lists of tidal frequencies on five different data sets around the world are compared. The prediction results using the first significant 50 constituents provided promising results on these locations of the world. Numéro de notice : A2014-516 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0737-5 Date de publication en ligne : 29/06/2014 En ligne : https://doi.org/10.1007/s00190-014-0737-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=74120
in Journal of geodesy > vol 88 n° 10 (October 2014) . - pp 975 - 988[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2014101 SL Revue Centre de documentation Revues en salle Disponible Reducing the draconitic errors in GNSS geodetic products / C.J. Rodriguez-Solano in Journal of geodesy, vol 88 n° 6 (June 2014)
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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]Exemplaires(1)
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)PermalinkEvaluation 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)PermalinkComparing 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)PermalinkManifold harmonic transform and spatial relationships for partial 3D object retrieval / Nguyen-Vu Hoang (April 2014)PermalinkPrise 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)PermalinkOn computing ellipsoidal harmonics using Jekeli’s renormalization / J. Sebera in Journal of geodesy, vol 86 n° 9 (September 2012)Permalink