WorldCat Identities

Dehant, Véronique 1959-

Overview
Works: 27 works in 61 publications in 3 languages and 721 library holdings
Genres: History  Observations 
Roles: Author, Author of introduction, Opponent, Author of afterword, colophon, etc., 958, 956, Editor
Publication Timeline
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Most widely held works by Véronique Dehant
Earth's core : dynamics, structure, rotation( )

13 editions published between 2003 and 2010 in English and held by 349 WorldCat member libraries worldwide

This volume contains 17 papers that are a mixture of presented papers from the Geophysical Union session on Core Dynamics, held in the Fall of 2000 in San Francisco, and invited papers for this volume. An international group of contributors present their research on topics grouped under the broad themes of seismology, mineral physics, geomagnetics and geodynamics, and geodosy. Individual topics include the Earth's free oscillations and the differential rotation of the inner core, complexity in PKP travel time data, thermal core-mantle interactions, and the core and fluctuations in the Earth's rotation. Annotation copyrighted by Book News, Inc., Portland, OR
Precession, nutation, and wobble of the Earth by Véronique Dehant( )

13 editions published between 2015 and 2018 in English and held by 220 WorldCat member libraries worldwide

Covering both astronomical and geophysical perspectives, this book describes changes in the Earth's orientation, specifically precession and nutation, and how they are observed and computed in terms of tidal forcing and models of the Earth's interior. Following an introduction to key concepts and elementary geodetic theory, the book describes how precise measurements of the Earth's orientation are made using observations of extra-galactic radio-sources by Very Long Baseline Interferometry techniques. It demonstrates how models are used to accurately pinpoint the location and orientation of the Earth with reference to the stars and how to determine variations in its rotation speed. A theoretical framework is also presented that describes the role played by the structure and properties of the Earth's deep interior. Incorporating suggestions for future developments in nutation theory for the next generation models, this book is ideal for advanced-level students and researchers in solid Earth geophysics, planetary science and astronomy
Internal loading of an inhomogeneous compressible earth with phase boundaries by P Defraigne( Book )

2 editions published between 1996 and 1997 in English and held by 94 WorldCat member libraries worldwide

Histoire de l'Observatoire royal de Belgique by Pierre Verhas( Book )

5 editions published in 2014 in French and held by 24 WorldCat member libraries worldwide

Fondé en 1826 par Guillaume Ier d'Orange-Nassau, l'Observatoire royal de Belgique est la plus ancienne et la plus importante institution scientifique de Belgique. Son concepteur, Adolphe Quetelet voulut en faire un institut au service de la recherche dans toutes les sciences d'observation de l'époque. 0L'Observatoire a toujours gardé son caractère pluridisciplinaire en dépit des aléas de l'histoire, ce qui lui a permis de prendre une part active et efficace à la considérable évolution de la Science tout au long de son existence.0Le propos de cet ouvrage est à la fois chronologique et méthodologique. Elle met en avant l'évolution des différentes disciplines scientifiques étudiées à l'Observatoire et leur influence sur les transformations successives de ses structures qui ont permis à cette institution de se maintenir, jusqu'à nos jours, au sommet de la recherche scientifique
Modeling of the apparent height variations of a Tranet station by Véronique Dehant( Book )

in English and held by 3 WorldCat member libraries worldwide

Report of the IAU Working Group on 'Nonrigid-Earth Nutation Theory'( )

2 editions published in 2000 in English and held by 3 WorldCat member libraries worldwide

The last precession-nutation model adopted by the International Astronomical Union (IAU) in 1980 is the nutation series built on Wahr's Earth transfer function for the nutations of an oceanless elastic Earth (Wahr, 1979, 1981), and on Kinoshita's rigid-Earth, precession-nutation series (Kinoshita, 1977; Kinoshita et al., 1979). The resulting precession and nonrigid-Earth nutation series have been used since that time and have been compared with observations. This comparison, which has been done by different teams all over the world, shows that the theoretical series must be improved to meet observational precision. A Working Group (WG) was set up to examine the possibility of adopting a new nonrigid-Earth nutation series and to study the existing possibilities. On the one hand, the rigid-Earth nutation series have been improved (three new series) and the mutual differences have been shown to be less than a few hundreds of microarcseconds. On the other hand, new Earth transfer functions have been derived based on additional physical considerations within the Earth. However, the problem with these transfer functions is that there is no reliable, independent information about the geophysical parameters needed to improve a theoretical model. Instead, the discrepancies with the nutation observations themselves are used to infer those parameters. Recent fits of geophysical parameters to the observed nutations have provided a series that is suitable for practical use, and is also a source of important information on the physics of the Earth's interior. This paper reviews the recent work of the WG and establishes the reasons and criteria for the choice of the new model IAU 2000, which is proposed for adoption at the next IAU General Assembly
Interprétation géophysique du mouvement du pôle : apport des observations de géodésie spatiale, de météorologie, d'océanographie et d'hydrologie by Lucía Seoane Corral( )

2 editions published between 2010 and 2011 in French and held by 3 WorldCat member libraries worldwide

The polar motion excitation is mainly due to the mass transport of the atmosphere and the oceans. So far, the observed motion is not fully explained from seasonal to diurnal scales. Our effort has focused on the Chandler wobble as well as fluctuations with period smaller than 50 days and diurnal variations, which remain still partially unexplained. We show that the atmospheric and oceanic mass redistributions are the principal causes of the Chandler wobble irregularities and the rapid polar motion of periods between 3 and 50 days. However, major differences persist at diurnal scales. Moreover, the redistributions of the continental water are important but, modelling those processes is imprecise due to the complexity and lack of observations of terrestrial hydrology. Current models must be then validated and compared to the observed polar motion. We show that the hydrological models, coupled with oceanic and atmospheric effects, improve the seasonal and long term mass balance. Thanks to space mission Gravity Discovery and Climate Experiment (GRACE), the total mass redistribution on the Earth can be determined with a different approach. Four analysis centers provide temporal variations of spherical harmonics C20, C21 and S21 of the gravity field that are proportional to the length of day and polar motion excitations caused by surface mass changes. We have analized the latest updates of these series. Despite a significant level of noise, their hydrological residual matches reasonably well the observed polar motion
The effect of mantle inelasticity on tidal gravity : a comparison between the spherical and the elliptical Earth model by Véronique Dehant( Book )

2 editions published in 1989 in English and held by 3 WorldCat member libraries worldwide

Astrométrie des satellites naturels : analyse d'observations anciennes pour l'amélioration des paramètres dynamiques des systèmes planétaires by Vincent Robert-Pélissier( )

2 editions published in 2011 in French and held by 3 WorldCat member libraries worldwide

The current study deals with the astrometric reduction of old photographic plates : we observe in the past. The main objective is to demonstrate that it is now possible to provide high-precise astrometric positions, by reducing a new time old photographic observations. We used photographic plates of the Galilean satellites taken at the McCormick Observatory between 1967 and 1998, and resulting in 2650 observations. Of course we had to create a complete procedure of analysis. We first digitized the entire plates archive with taking care of process itself, not to decrease the accuracy at this point. Then we created a procedure in order to provide astrometric positions. Softwares we developed to identify, extract and correct the positions, from the digitizations. A new astrometric reduction method by linking the stars was especially developed for the photographic plates analysis to determine high-precise (RA,Dec) astrometric positions and intersatellite positions of the Galilean satellites. We also corrected the data for various instrumental and spherical effects, such as the coma-magnetude effect or the total astmospheric refraction, due to the small number of reference stars available. For the first time with these plates, we were able to provide ICRS (Ra,Dec) astrometric positions, while only relative positions could be calculated. For the Jovian system, we now provide an accuracy about 75 mas for (RA,Dec) positions, and about of 36 mas for intersatellite positions. Note that the previous accuracy was about of 90 mas and only for intersatellite positions. More, the observations provide satellite positions and Jupiter positions too. Thus we used these results to compare star catalogs, Galilean and planetary ephemerides. They were also used to fit the last Galilean ephemeris provided by the IMCCE, with the observations
Improvement of the planetary ephemerides using spacecraft navigation data and its application to fundamental physics by Ashok Kumar Verma( Book )

2 editions published in 2013 in English and held by 2 WorldCat member libraries worldwide

The planetary ephemerides play a crucial role for spacecraft navigation, mission planning, reductionand analysis of the most precise astronomical observations. The construction of such ephemerides is highly constrained by the tracking observations, in particular range, of the space probes collected by the tracking stations on the Earth. The present planetary ephemerides (DE,INPOP, EPM) are mainly based on such observations. However, the data used by the planetary ephemerides are not the direct raw tracking data, but measurements deduced after the analysisof raw data made by the space agencies and the access to such processed measurements remains difficult in terms of availability. The goal of the thesis is to use archives of past and present space missions data independently from the space agencies, and to provide data analysis tools for the improvement of the planetary ephemerides INPOP, as well as to use improved ephemerides to perform tests ofphysics such as general relativity, solar corona studies, etc.The first part of the study deals with the analysis of the Mars Global Surveyor (MGS)tracking data as an academic case for understanding. The CNES orbit determination software GINS was used for such analysis. The tracking observations containing one-, two-, and three wayDoppler and two-way range are then used to reconstruct MGS orbit precisely and obtained results are consistent with those published in the literature. As a supplementary exploitationof MGS, we derived the solar corona model and estimated the average electron density alongthe line of sight separately for slow and fast wind regions. Estimated electron densities arecomparable with the one found in the literature. Fitting the planetary ephemerides, including additional data which were corrected for the solar corona perturbations, noticeably improves theextrapolation capability of the planetary ephemerides and the estimation of the asteroid masses (Verma et al., 2013a). The second part of the thesis deals with the complete analysis of the MESSENGER trackingdata. This analysis improved the Mercury ephemeris up to two order of magnitude comparedto any latest ephemerides. Such high precision ephemeris, INPOP13a, is then used to performgeneral relativity tests of PPN-formalism.[...]
À la recherche d'autres mondes : les exoplanètes by Yaël Nazé( Book )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

Habiter ailleurs que sur Terre, en dehors du système solaire, est-ce vraiment possible? Est-ce que la vie existe en dehors du Système solaire et comment la chercher? Ces questions sont celles que les hommes et les femmes se posent et celles qu'ils se sont posées de tout temps. Les scientifiques n'échappent pas à cette règle et nous vivons à une époque fascinante où cette recherche évolue extrêmement vite : ils ont découvert d'autres lieux potentiellement habitables ou habités, les exoplanètes, des planètes tournant autour d'autres soleils dans l'univers. A ce jour, plus de 900 exoplanètes ont ainsi été détectées! Yaël Nazé, dans cet ouvrage, montre où chercher les exoplanètes, comment les détecter, où les scientifiques en sont dans les découvertes, et à quoi ces exoplanètes pourraient ressembler. En somme, voici une jolie introduction à un sujet passionnant!
Elaboration des éphémérides INPOP : modèle dynamique et ajustement aux données de télémétrie Laser Lune by Hervé Manche( )

1 edition published in 2011 in French and held by 1 WorldCat member library worldwide

This thesis describes the set up of the dynamical model of the planetary an lunar ephemeris INPOP, and its adjustment to Lunar laser telemetry data. The first part contains general considerations about the modeling of forces and torques exerted upon Solar System bodies. These interactions, leading to the equations of motions, take into account the Newtonian main term, corrections due to the general relativity, perturbations due to some non spherical bodies or their deformation due to intern constraints (tidal effects). The second part deals with adjustments to Lunar Laser Ranging observations, the measurement of the light time travel between a station on the Earth and a reflector on the Moon. Their intrinsic precision reaches a few centimeters for the most recent ones. In the reduction process, it is thus necessary to take into account some very small physical effects, such as the displacement of the terrestrial crust or the relativistic deviation of light. Finally, the third part describes the constructions of three particular solutions. The first one, designed to retrieve the Jet Propulsion Laboratory's solution DE405, allows to validate the dynamical model. The second one corrects some inconsistancies and includes the Earth's orientation, in order to compute long time solutions. The third one, which model is improved, is fitted to LLR observations. The LLR residuals and fitted parameters values are compared to other published solutions
Habiter sur une lune du système solaire ? by Véronique Dehant( Book )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

Habiter sur Mars? by Véronique Dehant( Book )

1 edition published in 2012 in French and held by 1 WorldCat member library worldwide

Link between the retrograde - prograde nutations and nutations in obliquity and longitude by P Defraigne( Book )

1 edition published in 1995 in English and held by 1 WorldCat member library worldwide

Entwurf von Anschlüssen zwischen Stahl und Beton( )

1 edition published in 2014 in German and held by 1 WorldCat member library worldwide

Link between the retrograde-prograde nutations and nutations in obliquity and longitude by P Defraigne( Book )

1 edition published in 1995 in English and held by 1 WorldCat member library worldwide

On atmospheric pressure perturbations on precession and nutations by Véronique Dehant( Book )

1 edition published in 1996 in English and held by 1 WorldCat member library worldwide

Modélisation de la rotation de la terre et analyse conjointe des données du mouvement du pôle et de gravimétrie by Yann Ziegler( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

L'objectif principal de ce travail est d'améliorer notre compréhension de la rhéologie terrestre et du mouvement de Chandler qui en dépend. Nous calculons le facteur gravimétrique complexe à la période de Chandler par une analyse conjointe de séries temporelles gravimétriques et du mouvement du pôle. Nous montrons l'importance et les limites des corrections gravimétriques dans les analyses locales et l'intérêt d'une combinaison des données de différentes stations. Suivant une approche plus théorique, nous menons une étude analytique puis numérique afin de déterminer les solutions du problème des petites déformations d'une Terre homogène anélastique en rotation. L'influence de l'anélasticité sur la période et le facteur de qualité de Chandler est étudiée, et nous montrons que ce dernier est plus sensible que la période aux paramètres rhéologiques, notamment à la viscosité de Kelvin. Enfin, nous étudions, en domaine de Laplace, l'influence de la fréquence de forçage par une surcharge
Free and forced oscillations in the core and the mantle by Véronique Dehant( Book )

1 edition published in 1993 in English and held by 1 WorldCat member library worldwide

Due to the existence of normal modes, the response of the Earth to the luni-solar attraction has resonances. In particular, the nutations of the Earth's rotation and figure axis in space, contain resonances due to the retrograde free core nutation (FCN) and to the prograde free inner core nutation (FICN). These normal modes exist because the Earth is composed of an elastic, elliptical, rotating inner core in a liquid, elliptical, rotating outer core, which is itself in an elastic or inelastic, elliptical, rotating mantle. In this paper, we examine the effects induced by these free oscillations on the forced nutations. The differences between the observed and the computed nutations are reconsidered for four principal nutations. Although the annual retrograde nutation is better explained with a model having a reasonance at the right FCN frequency and at the FICN frequency, differences still remain between the other observed and the theoretical nutations and, in particular, at the prograde semi-annual nutation frequency. One possible explanation for this lies in the atmospheric loading effect on the nutations
 
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Earth's core : dynamics, structure, rotation
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Alternative Names
Dehant, V. 1959-

Dehant, Véronique M. 1959-

Veronique Dehant matemática y geofísica belga

Veronique Dehantová belgická geofyzička a matematička

Languages
English (39)

French (14)

German (1)