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129 results on '"Delva, Pacôme"'

1. Searching for large dark matter clumps using the Galileo Satnav clock variations

Author

Bertrand, Bruno, Defraigne, Pascale, Hees, Aurélien, Sheremet, Alexandra, Courde, Clément, Chabé, Julien, Ventura-Traveset, Javier, Dilssner, Florian, Schoenemann, Erik, Mendes, Luis, and Delva, Pacôme

Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics, General Relativity and Quantum Cosmology, High Energy Physics - Phenomenology, Physics - Atomic Physics, 83C56 (Primary) 81V45 (Secondary)
Abstract

This study presents bounds on transient variations of fundamental constants, with typical timescales ranging from minutes to months, using clocks in space. The underlying phenomenology describing such transient variations relies on models for Dark Matter (DM) which suggest possible encounters of macroscopic compact objects with the Earth, due to the motion of the solar system in the galactic halo. If such compact objects possess an effective feeble interaction with the ordinary matter beyond the gravitational one, it may result in effective transient variations of fundamental constants. Such variations leave signatures on clocks onboard GNSS satellites. In this paper, we introduce a phenomenological study dedicated to the search for such DM transient objects using the network of passive hydrogen masers (H-Masers) onboard Galileo satellites. We first model the signature of transient variations of fundamental constants as a frequency modulation in the difference between two satellite clocks, considering the satellite trajectories relative to the transient event. Then, we present first results based on a fast analysis method, the maximum reach analysis. The main result is a significant extension of the discovery range for DM transients, with a sensitivity never achieved before. We investigate indeed the range of transient sizes from $10^5$ to $10^9$ kilometres, which, apart from indirect and model-dependent non-transient effects, has never been explored previously., Comment: 13 pages, 11 figures, version accepted for publication in Advances in Space Research

Published
2024

2. GENESIS: Co-location of Geodetic Techniques in Space

Author

Delva, Pacôme, Altamimi, Zuheir, Blazquez, Alejandro, Blossfeld, Mathis, Böhm, Johannes, Bonnefond, Pascal, Boy, Jean-Paul, Bruinsma, Sean, Bury, Grzegorz, Chatzinikos, Miltiadis, Couhert, Alexandre, Courde, Clément, Dach, Rolf, Dehant, Véronique, Dell'Agnello, Simone, Elgered, Gunnar, Enderle, Werner, Exertier, Pierre, Glaser, Susanne, Haas, Rüdiger, Huang, Wen, Hugentobler, Urs, Jäggi, Adrian, Karatekin, Ozgur, Lemoine, Frank G., Poncin-Lafitte, Christophe Le, Lunz, Susanne, Männel, Benjamin, Mercier, Flavien, Métivier, Laurent, Meyssignac, Benoît, Müller, Jürgen, Nothnagel, Axel, Perosanz, Felix, Rietbroek, Roelof, Rothacher, Markus, Sert, Hakan, Sosnica, Krzysztof, Testani, Paride, Ventura-Traveset, Javier, Wautelet, Gilles, and Zajdel, Radoslaw

Subjects
Physics - Instrumentation and Detectors, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Atmospheric and Oceanic Physics, Physics - Applied Physics, Physics - Geophysics
Abstract

Improving and homogenizing time and space reference systems on Earth and, more directly, realizing the Terrestrial Reference Frame (TRF) with an accuracy of 1mm and a long-term stability of 0.1mm/year are relevant for many scientific and societal endeavors. The knowledge of the TRF is fundamental for Earth and navigation sciences. For instance, quantifying sea level change strongly depends on an accurate determination of the geocenter motion but also of the positions of continental and island reference stations, as well as the ground stations of tracking networks. Also, numerous applications in geophysics require absolute millimeter precision from the reference frame, as for example monitoring tectonic motion or crustal deformation for predicting natural hazards. The TRF accuracy to be achieved represents the consensus of various authorities which has enunciated geodesy requirements for Earth sciences. Today we are still far from these ambitious accuracy and stability goals for the realization of the TRF. However, a combination and co-location of all four space geodetic techniques on one satellite platform can significantly contribute to achieving these goals. This is the purpose of the GENESIS mission, proposed as a component of the FutureNAV program of the European Space Agency. The GENESIS platform will be a dynamic space geodetic observatory carrying all the geodetic instruments referenced to one another through carefully calibrated space ties. The co-location of the techniques in space will solve the inconsistencies and biases between the different geodetic techniques in order to reach the TRF accuracy and stability goals endorsed by the various international authorities and the scientific community. The purpose of this white paper is to review the state-of-the-art and explain the benefits of the GENESIS mission in Earth sciences, navigation sciences and metrology., Comment: 31 pages, 9 figures, submitted to Earth, Planets and Space (EPS)

Published
2022
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4. GENESIS: co-location of geodetic techniques in space

Author

Delva, Pacôme, Altamimi, Zuheir, Blazquez, Alejandro, Blossfeld, Mathis, Böhm, Johannes, Bonnefond, Pascal, Boy, Jean-Paul, Bruinsma, Sean, Bury, Grzegorz, Chatzinikos, Miltiadis, Couhert, Alexandre, Courde, Clément, Dach, Rolf, Dehant, Véronique, Dell’Agnello, Simone, Elgered, Gunnar, Enderle, Werner, Exertier, Pierre, Glaser, Susanne, Haas, Rüdiger, Huang, Wen, Hugentobler, Urs, Jäggi, Adrian, Karatekin, Ozgur, Lemoine, Frank G., Le Poncin-Lafitte, Christophe, Lunz, Susanne, Männel, Benjamin, Mercier, Flavien, Métivier, Laurent, Meyssignac, Benoît, Müller, Jürgen, Nothnagel, Axel, Perosanz, Felix, Rietbroek, Roelof, Rothacher, Markus, Schuh, Harald, Sert, Hakan, Sosnica, Krzysztof, Testani, Paride, Ventura-Traveset, Javier, Wautelet, Gilles, and Zajdel, Radoslaw

Published
2023
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5. New test of Lorentz invariance using the MICROSCOPE space mission

Author

Bars, Hélène Pihan-le, Guerlin, Christine, Hees, Aurélien, Peaucelle, Romain, Tasson, Jay D., Bailey, Quentin G., Mo, Geoffrey, Delva, Pacôme, Meynadier, Frédéric, Touboul, Pierre, Métris, Gilles, Rodrigues, Manuel, Bergé, Joël, and Wolf, Peter

Subjects
Physics - Space Physics, General Relativity and Quantum Cosmology
Abstract

We use data from the T-SAGE instrument on board the MICROSCOPE space mission to search for Lorentz violation in matter-gravity couplings as described by the Lorentz violating Standard-Model Extension (SME) coefficients $(\bar{a}_\text{eff})_\mu^w$, where ($\mu = T,X,Y,Z$) and ($w = e,p,n$) for the electron, proton and neutron. One of the phenomenological consequences of a non-zero value of those coefficients is that test bodies of different composition fall differently in an external gravitational field. This is similar to "standard" tests of the universality of free fall, but with a specific signature that depends on the orbital velocity and rotation of the Earth. We analyze data from five measurement sessions of MICROSCOPE spread over a year finding no evidence for such a signature, but setting constraints on linear combinations of the SME coefficients that improve on best previous results by one to two orders of magnitude. Additionally, our independent linear combinations are different from previous ones, which increases the diversity of available constraints, paving the way towards a full decorrelation of the individual coefficients.

Published
2019
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6. Gravitational redshift test with the future ACES mission

Author

Savalle, Etienne, Guerlin, Christine, Delva, Pacôme, Meynadier, Frédéric, Poncin-Lafitte, Christophe le, and Wolf, Peter

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, General Relativity and Quantum Cosmology
Abstract

We investigate the performance of the upcoming ACES (Atomic Clock Ensemble in Space) space mission in terms of its primary scientific objective, the test of the gravitational redshift. Whilst the ultimate performance of that test is determined by the systematic uncertainty of the on-board clock at 2-3 ppm, we determine whether, and under which conditions, that limit can be reached in the presence of colored realistic noise, data gaps and orbit determination uncertainties. To do so we have developed several methods and software tools to simulate and analyse ACES data. Using those we find that the target uncertainty of 2-3 ppm can be reached after only a few measurement sessions of 10-20 days each, with a relatively modest requirement on orbit determination of around 300 m., Comment: 31 pages, submitted to CQG

Published
2019
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8. Determination of a high spatial resolution geopotential model using atomic clock comparisons

Author

Lion, Guillaume, Panet, Isabelle, Wolf, Peter, Guerlin, Christine, Bize, Sébastien, and Delva, Pacôme

Subjects
Physics - Geophysics, Physics - Computational Physics, Physics - Optics
Abstract

Recent technological advances in optical atomic clocks are opening new perspectives for the direct determination of geopotential differences between any two points at a centimeter-level accuracy in geoid height. However, so far detailed quantitative estimates of the possible improvement in geoid determination when adding such clock measurements to existing data are lacking. We present a first step in that direction with the aim and hope of triggering further work and efforts in this emerging field of chronometric geodesy and geophysics. We specifically focus on evaluating the contribution of this new kind of direct measurements in determining the geopotential at high spatial resolution (~ 10 km). We studied two test areas, both located in France and corresponding to a middle (Massif Central) and high (Alps) mountainous terrain. These regions are interesting because the gravitational field strength varies greatly from place to place at high spatial resolution due to the complex topography. Our method consists in first generating a synthetic high resolution geopotential map, then drawing synthetic measurement data (gravimetry and clock data) from it, and finally reconstructing the geopotential map from that data using least squares collocation. The quality of the reconstructed map is then assessed by comparing it to the original one used to generate the data. We show that adding only a few clock data points (less than 1 % of the gravimetry data) reduces the bias significantly and improves the standard deviation by a factor 3. The effect of the data coverage and data quality on the results is investigated, and the trade-off between the measurement noise level and the number of data points is discussed., Comment: Published in Journal of Geodesy (Springer)

Published
2016
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10. Use of Geodesy and Geophysics Measurements to Probe the Gravitational Interaction

Author

Hees, Aurélien, Bourgoin, Adrien, Delva, Pacome, Le Poncin-Lafitte, Christophe, Wolf, Peter, van Beijeren, Henk, Series Editor, Blanchard, Philippe, Series Editor, Coecke, Bob, Series Editor, Dieks, Dennis, Series Editor, Dittrich, Bianca, Series Editor, Dürr, Detlef, Series Editor, Durrer, Ruth, Series Editor, Frigg, Roman, Series Editor, Fuchs, Christopher, Series Editor, Giulini, Domenico J. W., Series Editor, Jaeger, Gregg, Series Editor, Kiefer, Claus, Series Editor, Landsman, Nicolaas P., Series Editor, Maes, Christian, Series Editor, Murao, Mio, Series Editor, Nicolai, Hermann, Series Editor, Petkov, Vesselin, Series Editor, Ruetsche, Laura, Series Editor, Sakellariadou, Mairi, Series Editor, van der Merwe, Alwyn, Series Editor, Verch, Rainer, Series Editor, Werner, Reinhard F., Series Editor, Wüthrich, Christian, Series Editor, Young, Lai-Sang, Series Editor, Puetzfeld, Dirk, editor, and Lämmerzahl, Claus, editor

Published
2019
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11. Chronometric Geodesy: Methods and Applications

Author

Delva, Pacome, Denker, Heiner, Lion, Guillaume, van Beijeren, Henk, Series Editor, Blanchard, Philippe, Series Editor, Coecke, Bob, Series Editor, Dieks, Dennis, Series Editor, Dittrich, Bianca, Series Editor, Dürr, Detlef, Series Editor, Durrer, Ruth, Series Editor, Frigg, Roman, Series Editor, Fuchs, Christopher, Series Editor, Giulini, Domenico J. W., Series Editor, Jaeger, Gregg, Series Editor, Kiefer, Claus, Series Editor, Landsman, Nicolaas P., Series Editor, Maes, Christian, Series Editor, Murao, Mio, Series Editor, Nicolai, Hermann, Series Editor, Petkov, Vesselin, Series Editor, Ruetsche, Laura, Series Editor, Sakellariadou, Mairi, Series Editor, van der Merwe, Alwyn, Series Editor, Verch, Rainer, Series Editor, Werner, Reinhard F., Series Editor, Wüthrich, Christian, Series Editor, Young, Lai-Sang, Series Editor, Puetzfeld, Dirk, editor, and Lämmerzahl, Claus, editor

Published
2019
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12. An Autonomous Reference Frame for Relativistic GNSS

Author

Kostić, Uroš, Horvat, Martin, Carloni, Sante, Delva, Pacôme, and Gomboc, Andreja

Subjects
General Relativity and Quantum Cosmology
Abstract

Current GNSS systems rely on global reference frames which are fixed to the Earth (via the ground stations) so their precision and stability in time are limited by our knowledge of the Earth dynamics. These drawbacks could be avoided by giving to the constellation of satellites the possibility of constituting by itself a primary and autonomous positioning system, without any a priori realization of a terrestrial reference frame. Our work shows that it is possible to construct such a system, an Autonomous Basis of Coordinates, via emission coordinates. Here we present the idea of the Autonomous Basis of Coordinates and its implementation in the perturbed space-time of Earth, where the motion of satellites, light propagation, and gravitational perturbations are treated in the formalism of general relativity., Comment: 5 pages, 3 figures, in proceedings of the 4th International Colloquium: Scientific and Fundamental Aspects of the Galileo Programme, 4-6 December 2013, Prague, Czech Republic; removed unnecessary indices from eqs. 3,6,7 and corrected minus signs in eqs. 6 and 7

Published
2014

13. Atomic clocks: new prospects in metrology and geodesy

Author

Delva, Pacôme and Lodewyck, Jérôme

Subjects
Physics - Atomic Physics, General Relativity and Quantum Cosmology
Abstract

We present the latest developments in the field of atomic clocks and their applications in metrology and fundamental physics. In the light of recent advents in the accuracy of optical clocks, we present an introduction to the relativistic modelization of frequency transfer and a detailed review of chronometric geodesy., Comment: Proceedings of the Workshop "Relativistic Positioning Systems and their Scientific Applications" held in Brdo near Kranj, Slovenia, 19-21 September 2012. To appear in Acta Futura (http://www.esa.int/gsp/ACT/publications/ActaFutura/)

Published
2013

15. A relativistic and autonomous navigation satellite system

Author

Delva, Pacôme, Cadez, Andrej, Kostic, Uros, and Carloni, Sante

Subjects
General Relativity and Quantum Cosmology
Abstract

A relativistic positioning system has been proposed by Bartolom\'e Coll in 2002. Since then, several group developed this topic with different approaches. I will present a work done in collaboration with Ljubljana University and the ESA Advanced Concepts Team. We developed a concept, Autonomous Basis of Coordinates, in order to take advantage of the full autonomy of a satellite constellation for navigation and positioning, by means of satellite inter-links. I will present the advantages of this new paradigm and a number of potential application for reference systems, geophysics and relativistic gravitation., Comment: 4 pages, proceedings of the "Rencontres de Moriond", 2011 sessions in La Thuile, Aosta valley, Italy

Published
2011

16. A comparison between matter wave and light wave interferometers for the detection of gravitational waves

Author

Delva, Pacôme, Angonin, Marie-Christine, and Tourrenc, Philippe

Subjects
General Relativity and Quantum Cosmology
Abstract

We calculate and compare the response of light wave interferometers and matter wave interferometers to gravitational waves. We find that metric matter wave interferometers will not challenge kilometric light wave interferometers such as Virgo or LIGO, but could be a good candidate for the detection of very low frequency gravitational waves.

Published
2006
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28. New Test of Lorentz Invariance Using the MICROSCOPE Space Mission

Author

Bars, Hélène Pihan-le, primary, Guerlin, Christine, additional, Hees, Aurélien, additional, Peaucelle, Romain, additional, Tasson, Jay D., additional, Bailey, Quentin G., additional, Mo, Geoffrey, additional, Delva, Pacôme, additional, Meynadier, Frédéric, additional, Touboul, Pierre, additional, Métris, Gilles, additional, Rodrigues, Manuel, additional, Bergé, Joël, additional, and Wolf, Peter, additional

Published
2019
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29. Géodésie chronométrique

Author

Delva, Pacôme, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Théorie et métrologie, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

National audience

Published
2018

30. What are the altitudes of the atomic clocks at Paris observatory?

Author

Collilieux, Xavier, Delva, Pacôme, Heydel, Laurent, Lion, Guillaume, Bergerault, Fabien, Delaugerre, Raphaëlle, Évrard, Loïc, Gonnet, Sylvain, Pesce, Damien, Prezat, Patrice, Institut National de l'Information Géographique et Forestière [IGN] (IGN), and Collilieux, Xavier

Subjects
[SPI.OTHER]Engineering Sciences [physics]/Other, [SPI.OTHER] Engineering Sciences [physics]/Other, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.STU.GP] Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
Abstract

The accuracy of atomic clocks is becoming small enough to determine altitude differences at the centimeter level in the near future. Current research activities consist in developing and comparing clock frequencies, and in setting up time transfer techniques with the required precision. Today, surveyor still has to provide clock altitude differences by traditional methods to allow these comparisons. This article reports levelling carried out by IGN at Paris Observatory for two European scientific projects in which the SYRTE Laboratory is involved., L'exactitude des horloges optiques permet d'envisager dans le futur leur utilisation pour déterminer des différences d'altitudes à une précision centimétrique. Les développements actuels consistent à comparer les fréquences d'horloges en cours de développement. Ainsi, la mise en place de protocoles de comparaison constitue une première étape vers cet objectif. Aujourd'hui, c'est encore au géomètre, au moyen des techniques traditionnelles, de déterminer l'altitude des horloges pour permettre ces comparaisons et fournir une mesure de référence. Cet article décrit les opérations de nivellement effectuées par l'IGN à l'Observatoire de Paris dans le contexte de projets scientifiques européens impliquant le laboratoire SYRTE de l'Observatoire de Paris. Abstract (english) : The accuracy of atomic clocks is becoming small enough to determine altitude differences at the centimeter level in the near future. Current research activities consist in developing and comparing clock frequencies, and in setting up time transfer techniques with the required precision. Today, surveyor still has to provide clock altitude differences by traditional methods to allow these comparisons. This article reports levelling carried out by IGN at Paris Observatory for two European scientific projects in which the SYRTE Laboratory is involved.

Published
2018

31. Optimization of atomic clock locations for the geopotential determination from gravimetric network

Author

Lion, Guillaume, Coulot, David, Delva, Pacôme, Wolf, Peter, Bize, Sébastien, Panet, Isabelle, Systèmes de Référence Temps Espace (SYRTE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Théorie et métrologie, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, École nationale des sciences géographiques (ENSG), Institut National de l'Information Géographique et Forestière [IGN] (IGN), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2018

32. Testing fundamental physics with atomic clocks

Author

Delva, Pacôme, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2017

33. Galileo gravitational Redshift test with Eccentric sATellites (GREAT)

Author

Delva, Pacôme, Puchades, N., Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Published
2017

34. Optical clocks and geodesy

Author

Delva, Pacôme, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Published
2017

35. Test of special relativity using a fiber network of optical clocks

Author

Delva, Pacôme, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Published
2017

36. Les horloges atomiques: tests de la relativité et géodésie chronométrique

Author

Delva, Pacôme, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Published
2017

37. L'interaction entre science et GNSS à l'Agence Spatiale Européenne (ESA)

Author

Delva, Pacôme, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Théorie et métrologie, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

National audience; Le GSAC (GNSS Science Advisory Committee) conseille l'ESA pour l'exploitation scientifique des programmes de navigation, alors que le GNSO (Galileo/GNSS Navigation Science Office) coordonne les activités scientifiques liées aux GNSS à l'ESA. Je présenterais le rôle et les activités du GSAC et du GNSO. De plus, je présenterais les possibles évolutions de la seconde génération des satellites Galileo.

Published
2017

38. ACES MWL data Analysis center at SYRTE

Author

Meynadier, Frédéric, Delva, Pacôme, Le Poncin-Laffite, Christophe, Guerlin, C., Laurent, Philippe, Wolf, Peter, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Références micro-ondes et échelles de temps, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Théorie et métrologie, Laboratoire Kastler Brossel (LKB (Lhomond)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2017

39. Benefits of optical clocks for high spatial resolution geopotential determination

Author

Lion, Guillaume, Delva, Pacôme, Guerlin, Christine, Bize, Sébastien, Wolf, Peter, Panet, Isabelle, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Théorie et métrologie, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences et Technologies de l'Information Géographique (LaSTIG), École nationale des sciences géographiques (ENSG), Institut National de l'Information Géographique et Forestière [IGN] (IGN)-Institut National de l'Information Géographique et Forestière [IGN] (IGN), Laboratoire Kastler Brossel (LKB (Jussieu)), and École normale supérieure - Paris (ENS-PSL)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2016

40. Chronometric Geodesy and Fundamental Physics

Author

Delva, Pacôme, Puchades, Neus, Lodewyck, Jérôme, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Métrologie des fréquences optiques, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Théorie et métrologie

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; Atomic clocks are today essential for several daily life applications, such as the building of the International Atomic Time (TAI) or Global Navigation Satellite Systems (GNSS). With the new generation of optical clocks, they reach such accuracy and stability that they are now considered in practical applications for the measurement of gravitational potential differences, thanks to the Einstein effect, or gravitational redshift. Several projects explored the possibilities of using clocks in geodesy or geophysical applications and research. This context offers a fantastic opportunity to use atomic clocks to test fundamental physics. In this talk I will present two such studies for testing the gravitational redshift and Lorentz invariance.The first project is the "Galileo gravitational Redshift test with Eccentric sATellites" (GREAT), funded by the European Space Agency (ESA). Here we use the on-board atomic clocks of the Galileo satellites 5 and 6 to look for violations of general relativity theory. These two satellites were launched on August, 30th 2014 and, because of a technical problem, the launcher brought them on an elliptic orbit. An elliptic orbit induces a periodic modulation of the gravitational redshift while the good stability of recent GNSS clocks allows to test this periodic modulation to a very good level of accuracy. The Galileo 5 and 6 satellites, with their large eccentricity and on-board H-maser clocks, are hence perfect candidates to perform this test.In the second study we propose a test of special relativity theory using a network of distant optical lattice clocks located in France, Germany and Great-Britain. By exploiting the difference between the velocities of each clock in the inertial geocentric frame, due to their different positions on the surface of the Earth, we can test the time dilation effect. The connection between these clocks, achieved with phase-compensated optical fibers, allows for an unprecedented level of statistical resolution for the comparison of remote atomic clock, making such a test now competitive with the best Ives-Stillwell tests.

Published
2016

41. Test of the Gravitational Redshift with eccentric Galileo satellites

Author

Delva, Pacôme, Puchades, N., Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), and Galileo Technical University of Valencia

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Published
2016

43. Status of ESA/SYRTE GREAT activities

Author

Delva, Pacôme, Puchades, Neus, Wolf, Peter, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Théorie et métrologie, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2016

44. A new SLR station in Tahiti at the Galileo site

Author

Delva, Pacôme, Biancale, Richard, Exertier, Pierre, Courde, Clément, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Théorie et métrologie, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Centre National d'Études Spatiales [Toulouse] (CNES)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2016

45. Recent advances in the determination of a high spatial resolution geopotential model using chronometric geodesy

Author

Lion, Guillaume, Guerlin, Christine, Bize, Sébastien, Wolf, Peter, Delva, Pacôme, Panet, Isabelle, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Théorie et métrologie, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences et Technologies de l'Information Géographique (LaSTIG), École nationale des sciences géographiques (ENSG), Institut National de l'Information Géographique et Forestière [IGN] (IGN)-Institut National de l'Information Géographique et Forestière [IGN] (IGN), Laboratoire Kastler Brossel (LKB (Jussieu)), École normale supérieure - Paris (ENS-PSL), Métrologie des fréquences optiques, LAboratoire de REcherche en Géodésie [Paris] (LAREG), and Institut National de l'Information Géographique et Forestière [IGN] (IGN)-Institut National de l'Information Géographique et Forestière [IGN] (IGN)-École nationale des sciences géographiques (ENSG)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; Current methods to determine the geopotential are mainly based on indirect approaches using gravimetric, gradiometric and topographic data. Satellite missions (GRACE, GOCE) have contributed significantly to improve the knowledge of the Earth's gravity field with a spatial resolution of about 90 km, but it is not enough to access, for example, to the geoid variation in hilly regions. While airborne and ground-based gravimeters provide the high resolution, the problem of these technics is that the accuracy is hampered by the heterogeneous coverage of gravity data (ground and offshore). Recent technological advances in atomic clocks are opening new perspectives in the determination of the geopotential. To date, the best of them reach a stability of 1.6×10-18 (NIST, RIKEN Univ. Tokyo) in just 7 hours of integration, an accuracy of 2.0×10-18 (JILA). Using the relation of the relativistic gravitational redshift, this corresponds to a determination of geopotential differences at the 0.1 m²/s² level (or 1 cm in geoid height). In this context, the present work aims at evaluating the contribution of optical atomic clocks for the determination of the geopotential at high spatial resolution. To do that, we have studied a test area surrounding the Massif Central in the middle of southern of France. This region, consists in low mountain ranges and plateaus, is interesting because, the gravitational field strength varies greatly from place to place at high resolution due to the relief. Here, we present the synthetic tests methodology: generation of synthetic gravity and potential data, then estimation of the potential from these data using the least-squares collocation and assessment of the clocks contribution. We shall see how the coverage of the data points (realistic or not) can affect the results, and discuss how to quantify the trade-off between the noise level and the number of data points used.

Published
2016

46. Remote Optical and Fountain Clock Comparison Using BroadbandTWSTFT and GPS PPP

Author

Riedel, Franziska, Benkler, Erik, Abgrall, Michel, Achkar, Joseph, Al-Masoudi, A., P Barwood, G., Baynes, F. N., F a Baynham, C., Bilicki, Slawomir, Bize, Sébastien, Bookjans, Eva, Bowden, W., Calonico, D., Cerretto, G., Clivati, C., Costanzo, G., Defraigne, P., Delva, Pacôme, Donnellan, S., Dörscher, S., Gerginov, V., Gill, Patrick, M Godun, R., Grebing, C., Guéna, Jocelyne, Häfner, Sebastian, R Hill, I., Hobson, R., Huang, G., Huntemann, N., M Jones, J., a King, S., a Klein, H., Lamb, A., Le Targat, Rodolphe, Leute, J., Levi, Federico, Lipphardt, B., Lisdat, Christian, Lodewyck, Jérôme, S Margolis, H., Menchetti, M., B R Nisbet-Jones, P., Ozimek, F., Peik, E., Petit, Gérard, Piester, Dirk, Pizzocaro, M., Rolland, A., Rotondo, M., Rovera, Daniele, Rust, F., Sanner, C., Schäfer, Wolfgang, Sesia, I., Shemar, S. L., Szymaniec, K., Tamm, Chr., Weyers, Stefan, Whibberley, P. B., Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Métrologie des fréquences optiques, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Références micro-ondes et échelles de temps, and Théorie et métrologie

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; Various Yb ion, Sr lattice and Cs fountain clocks at INRiM, LNE-SYRTE, NPL and PTB had been compared simultaneously over a 3-week campaign using satellite-based techniques. With full 20 MChip/s modulation bandwidth TWSTFT links and PPP/iPPP analysis of GPS link data,instabilities of a few 1E-16 could be achieved for both techniques. For the calculation of the clock-to-clock ratios and their uncertainties, gap-tolerant weighted averaging with differentoptimized weighting functions was employed.

Published
2016

47. Contribution des horloges optiques pour la détermination du géopotentiel à haute résolution spatiale

Author

Lion, Guillaume, Panet, Isabelle, Delva, Pacôme, Bize, Sébastien, Wolf, Peter, Guerlin, Christine, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Théorie et métrologie, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences et Technologies de l'Information Géographique (LaSTIG), École nationale des sciences géographiques (ENSG), Institut National de l'Information Géographique et Forestière [IGN] (IGN)-Institut National de l'Information Géographique et Forestière [IGN] (IGN), Laboratoire Kastler Brossel (LKB (Jussieu)), and École normale supérieure - Paris (ENS-PSL)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

National audience

Published
2016

48. Applying and testing chronometric Geodesy

Author

Delva, Pacôme, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Théorie et métrologie, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2016

49. The ILRS campaign for the GREAT experiment

Author

Puchades Colmenero, Neus, Delva, Pacôme, Exertier, Pierre, Wolf, Peter, Deleflie, Florent, Loyer, Sylvain, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Théorie et métrologie, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Planetology and Environments from Ground Astrometry and Space Exploration (PEGASE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Centre National d'Études Spatiales [Toulouse] (CNES)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2016

50. Testing the gravitational redshift effect with Galileo satellites

Author

Puchades Colmenero, Neus, Delva, Pacôme, Wolf, Peter, Richard, Edouard, Exertier, Pierre, Hess, Aurelien, Bertone, Stefano, Systèmes de Référence Temps Espace (SYRTE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Théorie et métrologie, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Departament of Mathematics, and Universität Bern [Bern] (UNIBE)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2016

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