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Time, atomics clocks and relativistic geodesy / Enrico Mai (2013)
Titre : Time, atomics clocks and relativistic geodesy Type de document : Monographie Auteurs : Enrico Mai, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 2013 Collection : DGK - A Sous-collection : Theoretische Geodäsie num. 124 Importance : 126 p. Format : 31 x 30 cm ISBN/ISSN/EAN : 978-3-7696-8204-5 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] horloge atomique
[Termes IGN] temps atomique international
[Termes IGN] temps de propagation
[Termes IGN] théorie de la relativitéIndex. décimale : 30.43 Travaux de géodésie physique Résumé : (Documentaliste) Après une première partie qui passé en revue les notions de temps, les effets de la relativité sont abordés. Puis l'auteur se focalise sur les problèmes de temps et de transfert de fréquence en géodésie spatiale concernés par la relativité. L'usage des horloges atomiques en géodésie nécessite un cadre mathématique particulier. Une approche de la géodésie relativiste est développée, elle établit par exemple, le concept de géoïde relativiste et introduit des réflexions en géodésie physique notamment. Note de contenu : Introduction
Time
1 The search for the nature of time
2 The measurement of time
3 The different notions of time
4 The problem of a unified concept of time
5 The role of fundamental quantities and physical dimensions
6 The realization of time scales
7 The choice of an underlying theory and its impact on definitions
8 The backing of a theory by experiments
9 The different kinds of geometry
10 The fundamental role of the line element
Relativistic Effects
11 Testing the concept of relativity
12 Focussing on Einstein's theory of relativity
13 Testing relativity via earthbound and space-bound experiments
14 Alternative modeling of gravitation
15 Progression of the interferometric method for relativity testing
16 Clocks as relativistic sensors
17 Apparent limits on the resolution
Transition to relativistic geodesy
18 Selected technological issues
19 Clock networks requiring time and frequency transfer
20 Time and frequency transfer via clock transportation
21 Time and frequency transfer via signal transmission
22 Time and frequency transfer methods
Geodetic use of atomic clocks
23 Decorrelation of physical effects by means of clock readings
24 From theoretical relativistic framework to real world scenarios
25 The resurrection of the chronometric leveling idea .
26 The improvement of gravity field determination techniques
27 Further potential applications of highly precise atomic clocks
28 The relativistic approach in satellite orbit calculation
Outline of the mathematical framework
29 Introduction of fundamental relations
29.1 Equation of a geodesic
29.2 Riemannian curvature tensor
29.3 Edtvos tensor and Marussi tensor
29.4 Ricci curvature tensor and fundamental metric tensors
29.5 Line element and special relativity
29.6 Proper time and generalized Doppler effect
29.7 Gravity and space-time metric
29.8 Einstein field equations
29.9 Special case: Schwarzschild metric and resulting testable relativistic effects
29.10 Inertial systems and general relativity
29.11 Geodesic deviation equation
29.12 Separability of different kinds of forces
29.13 Various relativistic effects
29.14 Proper time and gravitational time delay
29.15 Superposition and magnitude of individual relativistic effects
30 Essential expressions for relativistic geodesy
30.1 Specific relations between coordinate time and proper time
30.2 Problem-dependent fixing of the tensors
30.3 BK-approach vs DSX-approach
30.4 Celestial reference system connected to the (solar-system) barycenter
30.5 Celestial reference system connected to the geocenter
30.6 Classical spherical harmonics and relativistic multipole moments
30.7 Earth's metric potentials in relativistic mass and spin multipole moments
30.8 Transformation between global and local reference systems
30.9 External and tidal potentials in post-Newtonian approximation
30.10 Transformation between BCRS and GCRS
30.11 Remarks on various spin-related terms
30.12 Remarks on various kinds of mass-multipole moments
30.13 Gravitational potential knowledge and time transformation
30.14 Topocentric reference system connected to (earthbound) observation sites
30.15 Specific relations between geocentric time and proper time
30.16 Post-Newtonian gravimetry and gradiometry
30.17 Definition of a relativistic geoid
Clock based height determination
31 Practical time scales and their relations
32 Potential differences and classical height systems
33 The global vertical datum problem
34 Introductory remarks on the displacement of observation sites
35 Introductory remarks on tides and the tidal potential
36 The modeling of tides
37 Tidal displacement and the role of Love and Shida numbers
38 Details on the tidal potential and resulting displacements
39 Sensitivity of clocks to tidally induced potential differences
40 Sensitivity of clocks to the tidally induced Doppler effect
41 Concluding remarks on the comparison of clocks
Outlook ReferencesNuméro de notice : 15742 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=62767 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 15742-01 30.43 Livre Centre de documentation Géodésie Disponible New constraints on the origin of the Hawaiian swell from wavelet analysis of the geoid-to-topography ratio / Cécilia Cadio in Earth and planetary science letters, vol 359–360 (15 December 2012)
[article]
Titre : New constraints on the origin of the Hawaiian swell from wavelet analysis of the geoid-to-topography ratio Type de document : Article/Communication Auteurs : Cécilia Cadio, Auteur ; Maxim D. Ballmer, Auteur ; Isabelle Panet , Auteur ; Michel Diament , Auteur ; Neil Ribe, Auteur Année de publication : 2012 Article en page(s) : pp 40 - 54 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] anomalie de pesanteur
[Termes IGN] convection
[Termes IGN] géoïde local
[Termes IGN] Hawaii (Etats-Unis)
[Termes IGN] houle
[Termes IGN] lithosphère
[Termes IGN] ondelette
[Termes IGN] transformation en ondelettes
[Termes IGN] volcanRésumé : (Auteur) Analyzing the formation mechanism of hotspot swells enhances our understanding of intraplate volcanism and the underlying geodynamical processes. The two main hypotheses for the origin of the archetypal Hawaiian swell are thermal lithospheric thinning, and dynamic support by an ascending plume. Any successful model would have to be able to simultaneously explain the swell topography and the corresponding geoid anomaly. In simple models of isostatic compensation, the geoid-to-topography ratio (GTR) is linearly related to the depth of the compensating mass; therefore it is often considered a fundamental parameter to assess swell support mechanisms. Previous estimates for the geoid-to-topography ratio (GTR) of the Hawaiian swell however are biased towards low values by incomplete removal of the effects of volcanic loading and lithospheric flexure. In order to resolve these issues, we here apply a continuous wavelet transform, which allows resolution of lateral variations of the GTR at various spatial scales. In a series of synthetic tests, the robustness of this approach and its power to identify the origin of hotspot swells are established. With 8 m/km on the youngest part of the chain, the recovered GTR agrees well with the predictions for dynamic support, therefore ruling out thermal rejuvenation as an important mechanism. We also find that the depth of the compensating mass decays by 20 km over a distance of 500 km from Hawaii to Kauai, and identify sublithospheric erosion by small-scale convection in the ponded plume material as a viable mechanism to support this decay. Numéro de notice : A2012-740 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.epsl.2012.10.006 Date de publication en ligne : 05/11/2012 En ligne : https://doi.org/10.1016/j.epsl.2012.10.006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91475
in Earth and planetary science letters > vol 359–360 (15 December 2012) . - pp 40 - 54[article]High-frequency signal and noise estimates of CSR GRACE RL04 / J.A. Bonin in Journal of geodesy, vol 86 n° 12 (December 2012)
[article]
Titre : High-frequency signal and noise estimates of CSR GRACE RL04 Type de document : Article/Communication Auteurs : J.A. Bonin, Auteur ; S. Bettadpur, Auteur ; B. Tapley, Auteur Année de publication : 2012 Article en page(s) : pp 1165 - 1177 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] bruit (théorie du signal)
[Termes IGN] données GRACE
[Termes IGN] erreur
[Termes IGN] filtrage du bruit
[Termes IGN] force de gravitation
[Termes IGN] levé gravimétrique
[Termes IGN] rapport signal sur bruit
[Termes IGN] traitement du signalRésumé : (Auteur) A sliding window technique is used to create daily-sampled Gravity Recovery and Climate Experiment (GRACE) solutions with the same background processing as the official CSR RL04 monthly series. By estimating over shorter time spans, more frequent solutions are made using uncorrelated data, allowing for higher frequency resolution in addition to daily sampling. Using these data sets, high-frequency GRACE errors are computed using two different techniques: assuming the GRACE high-frequency signal in a quiet area of the ocean is the true error, and computing the variance of differences between multiple high-frequency GRACE series from different centers. While the signal-to-noise ratios prove to be sufficiently high for confidence at annual and lower frequencies, at frequencies above 3 cycles/year the signal-to-noise ratios in the large hydrological basins looked at here are near 1.0. Comparisons with the GLDAS hydrological model and high frequency GRACE series developed at other centers confirm CSR GRACE RL04’s poor ability to accurately and reliably measure hydrological signal above 3–9 cycles/year, due to the low power of the large-scale hydrological signal typical at those frequencies compared to the GRACE errors. Numéro de notice : A2012-651 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-012-0572-5 Date de publication en ligne : 03/06/2012 En ligne : https://doi.org/10.1007/s00190-012-0572-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32097
in Journal of geodesy > vol 86 n° 12 (December 2012) . - pp 1165 - 1177[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2012121 RAB Revue Centre de documentation En réserve L003 Disponible Recent changes of the Earth’s core derived from satellite observations of magnetic and gravity fields / Mioara Mandea in Proceedings of the National Academy of Sciences of the United States of America PNAS, vol 109 n° 47 (November 2012)
[article]
Titre : Recent changes of the Earth’s core derived from satellite observations of magnetic and gravity fields Type de document : Article/Communication Auteurs : Mioara Mandea, Auteur ; Isabelle Panet , Auteur ; Vincent Lesur, Auteur ; Olivier de Viron, Auteur ; Michel Diament , Auteur ; Jean-Louis Le Mouël, Auteur Année de publication : 2012 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] champ géomagnétique
[Termes IGN] données CHAMP
[Termes IGN] données GRACE
[Termes IGN] géocentre
[Termes IGN] variation temporelleRésumé : (Auteur) To understand the dynamics of the Earth’s fluid, iron-rich outer core, only indirect observations are available. The Earth’s magnetic field, originating mainly within the core, and its temporal variations can be used to infer the fluid motion at the top of the core, on a decadal and subdecadal time-scale. Gravity variations resulting from changes in the mass distribution within the Earth may also occur on the same time-scales. Such variations include the signature of the flow inside the core, though they are largely dominated by the water cycle contributions. Our study is based on 8 y of high-resolution, high-accuracy magnetic and gravity satellite data, provided by the CHAMP and GRACE missions. From the newly derived geomagnetic models we have computed the core magnetic field, its temporal variations, and the core flow evolution. From the GRACE CNES/GRGS series of time variable geoid models, we have obtained interannual gravity models by using specifically designed postprocessing techniques. A correlation analysis between the magnetic and gravity series has demonstrated that the interannual changes in the second time derivative of the core magnetic field under a region from the Atlantic to Indian Ocean coincide in phase with changes in the gravity field. The order of magnitude of these changes and proposed correlation are plausible, compatible with a core origin; however, a complete theoretical model remains to be built. Our new results and their broad geophysical significance could be considered when planning new Earth observation space missions and devising more sophisticated Earth’s interior models. Numéro de notice : A2012-735 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1073/pnas.1207346109 Date de publication en ligne : 10/09/2012 En ligne : https://doi.org/10.1073/pnas.1207346109 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91455
in Proceedings of the National Academy of Sciences of the United States of America PNAS > vol 109 n° 47 (November 2012)[article]On computing ellipsoidal harmonics using Jekeli’s renormalization / J. Sebera in Journal of geodesy, vol 86 n° 9 (September 2012)
[article]
Titre : On computing ellipsoidal harmonics using Jekeli’s renormalization Type de document : Article/Communication Auteurs : J. Sebera, Auteur ; Johannes Bouman, Auteur ; W. Bosch, Auteur Année de publication : 2012 Article en page(s) : pp 713 - 726 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] Earth Gravity Model 2008
[Termes IGN] fonction hypergéométrique
[Termes IGN] harmonique ellipsoïdale
[Termes IGN] potentiel de pesanteur terrestre
[Termes IGN] transformation de LegendreRésumé : (Auteur) Gravity data observed on or reduced to the ellipsoid are preferably represented using ellipsoidal harmonics instead of spherical harmonics. Ellipsoidal harmonics, however, are difficult to use in practice because the computation of the associated Legendre functions of the second kind that occur in the ellipsoidal harmonic expansions is not straightforward. Jekeli’s renormalization simplifies the computation of the associated Legendre functions. We extended the direct computation of these functions—as well as that of their ratio—up to the second derivatives and minimized the number of required recurrences by a suitable hypergeometric transformation. Compared with the original Jekeli’s renormalization the associated Legendre differential equation is fulfilled up to much higher degrees and orders for our optimized recurrences. The derived functions were tested by comparing functionals of the gravitational potential computed with both ellipsoidal and spherical harmonic syntheses. As an input, the high resolution global gravity field model EGM2008 was used. The relative agreement we found between the results of ellipsoidal and spherical syntheses is 10-14, 10-12 and 10-8 for the potential and its first and second derivatives, respectively. Using the original renormalization, this agreement is 10-12, 10-8 and 10-5, respectively. In addition, our optimized recurrences require less computation time as the number of required terms for the hypergeometric functions is less. Numéro de notice : A2012-468 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-012-0549-4 Date de publication en ligne : 07/03/2012 En ligne : https://doi.org/10.1007/s00190-012-0549-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31914
in Journal of geodesy > vol 86 n° 9 (September 2012) . - pp 713 - 726[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2012091 RAB Revue Centre de documentation En réserve L003 Disponible Reducing errors in the GRACE gravity solutions using regularization / H. Save in Journal of geodesy, vol 86 n° 9 (September 2012)PermalinkMonitoring GOCE gradiometer calibration parameters using accelerometer and star sensor data: methodology and first results / C. Siemes in Journal of geodesy, vol 86 n° 8 (August 2012)PermalinkOptimal regularization for geopotential model GOCO02S by Monte Carlo methods and multi-scale representation of density anomalies / Karl Rudolf Koch in Journal of geodesy, vol 86 n° 8 (August 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)PermalinkSeparation of global time-variable gravity signals into maximally independent components / E. Forootan in Journal of geodesy, vol 86 n° 7 (July 2012)PermalinkAssessment of the GOCE-based global gravity models in Canada / Elmas Sinem Ince in Geomatica, vol 66 n° 2 (June 2012)PermalinkChoix d'un modèle géopotentiel global pour la détermination du géoïde en Algérie / N. Rabehi in Bulletin des sciences géographiques, n° 27 (juin 2012)PermalinkEstimation of the zero-height geopotential level WoLVD in a local vertical datum from inversion of co-located GPS, leveling and geoid heights: a case study in the Hellenic islands / Christopher Kotsakis in Journal of geodesy, vol 86 n° 6 (June 2012)PermalinkPermalinkWavelet‐based directional analysis of the gravity field : evidence for large‐scale undulations / M. Hayn in Geophysical journal international, vol 189 n° 3 (June 2012)PermalinkEstimating geoid height change in North America: past, present and future / T. Jacob in Journal of geodesy, vol 86 n° 5 (May 2012)PermalinkSimulation study of a follow-on gravity mission to GRACE / B. Loomis in Journal of geodesy, vol 86 n° 5 (May 2012)PermalinkPermalinkPermalinkDétermination du champ de pesanteur par gradiométrie spatiale [diaporama] / Gwendoline Pajot-Métivier (2012)PermalinkEntwicklung eines Kalman-Filters zur Bestimmung kurzzeitiger Variationen des Erdschwerefeldes aus daten der Satellitenmission GRACE / E. Kurtenbach (2012)PermalinkFlexible dataset combination and modelling by domain decomposition approaches / Isabelle Panet (2012)PermalinkGeodesy / Wolfgang Torge (2012)PermalinkIntroduction à l’astronomie de position / Jonathan Chenal (2012)PermalinkGOCE gravitational gradients along the orbit / Johannes Bouman in Journal of geodesy, vol 85 n° 11 (November /2011)Permalink