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Evaluation of terrestrial and airborne gravity data over Antarctica : a generic approach / Philipp Zingerle in Journal of geodetic science, vol 9 n° 1 (January 2019)
[article]
Titre : Evaluation of terrestrial and airborne gravity data over Antarctica : a generic approach Type de document : Article/Communication Auteurs : Philipp Zingerle, Auteur ; Roland Pail, Auteur ; M. Scheinert, Auteur ; T. Schaller, Auteur Année de publication : 2019 Article en page(s) : pp 29 - 40 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] Antarctique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] données localisées 3D
[Termes IGN] levé gravimétrique
[Termes IGN] modèle de géopotentielRésumé : (auteur) The AntGrav project, funded by the German Research Foundation (DFG) has the main objective to homogenize and optimize Antarctic gravity field information. Within this project an evaluation procedure is needed to inspect all different kind of gravity field surveys available in Antarctica. In this paper a suitable methodology is proposed.
We present an approach for fast 3D gravity point data reduction in different spectral bands. This is achieved through pre-calculating a fine 3D mesh of synthesized gravity functionals over the entirety of the Antarctic continent, for which two different global models are used: the combined satellite model GOCO05s for the long-wavelength part, and the topographic model Earth2014 for the shorter wavelengths. To maximize the applicability separate meshes are calculated for different spectral bands in order to specifically reduce a certain band or a selected combination. All meshes are calculated for gravity anomalies as well as gravity disturbances. Utilizing these meshes, synthesized gravity data at arbitrary positions is computed by conventional 3D interpolation methods (e.g. linear, cubic or spline).
It is shown that the applied approach can reach a worst-case interpolation error of less than 1 mGal. Evaluation results are presented for the AntGG grid and exemplary for the in-situ measurements of the AGAP and BAS-LAND campaigns. While general properties, large-scale errors and systematic effects can usually be detected, small-scale errors (e.g. of single points) are mostly untraceable due to the uncertainties within the topographic model.Numéro de notice : A2019-408 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1515/jogs-2019-0004 Date de publication en ligne : 19/08/2019 En ligne : https://doi.org/10.1515/jogs-2019-0004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93526
in Journal of geodetic science > vol 9 n° 1 (January 2019) . - pp 29 - 40[article]GPS-derived geocenter motion from the IGS second reprocessing campaign / Liansheng Deng in Earth, Planets and Space, vol 71 (2019)
[article]
Titre : GPS-derived geocenter motion from the IGS second reprocessing campaign Type de document : Article/Communication Auteurs : Liansheng Deng, Auteur ; Zhao Li, Auteur ; Na Wei, Auteur ; Yifang Ma , Auteur ; Hua Chen, Auteur Année de publication : 2019 Article en page(s) : n° 74 Note générale : bibloigraphie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] campagne d'observations
[Termes IGN] mouvement du géocentre
[Termes IGN] télémétrie laser sur satelliteRésumé : (auteur) GPS data processing methods and theories are under continuous refinement in the past 30 years. Using the latest products is supposed to provide more stable and reliable geocenter estimates. In this paper, geocenter estimates from deformation inversion approach with new observations of IGS second data reprocessing campaign (IG2) are investigated. Results indicate that our IG2-derived geocenter motion estimates agree well with solutions from network approach for SLR. The truncated degree 5 exhibits the highest consistency between GPS-inverted geocenter estimates and the SLR results in both annual amplitudes and phases. Then, the GPS-derived geocenter motions are compared with results from other different approaches. We find that except for a discrepancy in the annual phase estimates of Z component, geocenter motions predicted with the IG2 data are in line with those based on other techniques. In addition, the effects of the translational parameters and the comparison with the IGS first data reprocessing campaign (IG1)-estimated geocenter motions are investigated, and results demonstrate that the translation parameters should be estimated when inversing the geocenter motion with the newly IG2 solutions and the advantage of the IG2 data reprocessing over the previous IG1 efforts. Finally, we address the impacts of post-seismic effects and the missing ocean data on the IG2-derived solutions. After removing the stations affected by large earthquakes, the amplitudes of Y component become higher, but the annual phases of the Y component become far away from the SLR solutions. Comparisons of the equivalent water height from the IG2-estimated coefficients and the solutions from the estimation of the circulation and climate of the ocean indicate that the differences between the two types of solutions vary with different truncated degrees, and the consistency is getting worse and worse with the truncated degree grows. Further researches still need to be done to invert surface mass variation coefficients from various combinations of GPS observations, ocean models and other datasets. Numéro de notice : A2019-669 Affiliation des auteurs : Géodésie+Ext (mi2018-2019) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1186/s40623-019-1054-2 Date de publication en ligne : 05/07/2019 En ligne : https://doi.org/10.1186/s40623-019-1054-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99940
in Earth, Planets and Space > vol 71 (2019) . - n° 74[article]How IGN (France) computed the so-called "centre of gravity" of physical Europe in 1989 and 2004 / Jean-François Hangouët (2019)
Titre : How IGN (France) computed the so-called "centre of gravity" of physical Europe in 1989 and 2004 Type de document : Article/Communication Auteurs : Jean-François Hangouët , Auteur Editeur : Ithaca [New York - Etats-Unis] : ArXiv - Université Cornell Année de publication : 2019 Importance : 5 p. Format : 21 x 30 cm Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] aplatissement
[Termes IGN] centre de gravité
[Termes IGN] ellipsoïde international
[Termes IGN] épistémologie
[Termes IGN] Europe (géographie physique)
[Termes IGN] Institut national de l'information géographique et forestière (France)
[Termes IGN] sphèroïdeRésumé : (auteur) The method used by senior geodetic engineer Jean-Georges Affholder to determine what can be termed as the ‘centre of gravity’ of physical Europe in 1989 and 2004 relies on mathematical formulae which, in their only published version, happen to be flawed with typographical errors that do not reflect Mr. Affholder’s actual mathematical exactness. This short epistemological paper summarizes the major steps of Affholder’s method, provides a corrected version of the general formulae, and briefly recalls some particulars of the specific determination of the centre of gravity of physical Europe. Numéro de notice : P2019-005 Affiliation des auteurs : ENSG (2012-2019) Thématique : POSITIONNEMENT Nature : Preprint nature-HAL : Préprint DOI : 10.48550/arXiv.1910.04252 Date de publication en ligne : 08/10/2019 En ligne : https://doi.org/10.48550/arXiv.1910.04252 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93787 Mass variation observing system by high low inter-satellite links (MOBILE) : a new concept for sustained observation of mass transport from space / Roland Pail in Journal of geodetic science, vol 9 n° 1 (January 2019)
[article]
Titre : Mass variation observing system by high low inter-satellite links (MOBILE) : a new concept for sustained observation of mass transport from space Type de document : Article/Communication Auteurs : Roland Pail, Auteur ; Jonathan Bamber, Auteur ; Richard Biancale, Auteur ; Rory Bingham, Auteur ; Carla Braitenberg, Auteur ; Annette Eicker, Auteur ; Frank Flechtner, Auteur ; Thomas Gruber, Auteur ; Andreas Güntner, Auteur ; Gerhard Heinzel, Auteur ; Martin Horwath, Auteur ; Laurent Longuevergne, Auteur ; J. Muller, Auteur ; Isabelle Panet , Auteur ; Hubert Savenije, Auteur ; S. Seneviratne, Auteur ; Nico Sneeuw, Auteur ; Tonie M. van Dam, Auteur ; Bert Wouters, Auteur Année de publication : 2019 Projets : 1-Pas de projet / Article en page(s) : pp 48 - 58 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] gravimétrie spatiale
[Termes IGN] harmonique sphérique
[Termes IGN] masseRésumé : (auteur) As changes in gravity are directly related to mass variability, satellite missions observing the Earth’s time varying gravity field are a unique tool for observing mass transport processes in the Earth system, such as the water cycle, rapid changes in the cryosphere, oceans, and solid Earth processes, on a global scale. The observation of Earth’s gravity field was successfully performed by the GRACE and GOCE satellite missions, and will be continued by the GRACE Follow-On mission. A comprehensive team of European scientists proposed the next-generation gravity field mission MOBILE in response to the European Space Agency (ESA) call for a Core Mission in the frame of Earth Explorer 10 (EE10). MOBILE is based on the innovative observational concept of a high-low tracking formation with micrometer ranging accuracy, complemented by new instrument concepts. Since a high-low tracking mission primarily observes the radial component of gravity-induced orbit perturbations, the error structure is close to isotropic. This geometry significantly reduces artefacts of previous along-track ranging low-low formations (GRACE, GRACE-Follow-On) such as the typical striping patterns. The minimum configuration consists of at least two medium-Earth orbiters (MEOs) at 10000 km altitude or higher, and one low-Earth orbiter (LEO) at 350-400 km. The main instrument is a laser-based distance or distance change measurement system, which is placed at the LEO. The MEOs are equipped either with passive reflectors or transponders. In a numerical closed-loop simulation, it was demonstrated that this minimum configuration is in agreement with the threshold science requirements of 5 mm equivalent water height (EWH) accuracy at 400 km wavelength, and 10 cm EWH at 200 km. MOBILE provides promising potential future perspectives by linking the concept to existing space infrastructure such as Galileo next-generation, as future element of the Copernicus/Sentinel programme, and holds the potential of miniaturization even up to swarm configurations. As such MOBILE can be considered as a precursor and role model for a sustained mass transport observing system from space. Numéro de notice : A2019-635 Affiliation des auteurs : Géodésie+Ext (mi2018-2019) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1515/jogs-2019-0006 Date de publication en ligne : 21/10/2019 En ligne : https://doi.org/10.1515/jogs-2019-0006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95454
in Journal of geodetic science > vol 9 n° 1 (January 2019) . - pp 48 - 58[article]Optimization of optical clock network for the geopotential determination / Guillaume Lion (2019)
Titre : Optimization of optical clock network for the geopotential determination Type de document : Article/Communication Auteurs : Guillaume Lion , Auteur ; Isabelle Panet , Auteur ; David Coulot , Auteur ; Pacôme Delva, Auteur Editeur : Saint-Mandé : Institut national de l'information géographique et forestière - IGN (2012-) Année de publication : 2019 Conférence : AGU 2019 Fall Meeting 09/12/2019 13/12/2019 San Francisco Californie - Etats-Unis programme sans actes Projets : ChronoG2o / Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] chronométrie
[Termes IGN] décalage d'horloge
[Termes IGN] horloge optique
[Termes IGN] optimisation (mathématiques)
[Termes IGN] potentiel de pesanteur terrestreRésumé : (auteur) Clock comparisons with an uncertainty at the 10−18 in terms of relative frequency can provide a new kind of measurement to improve our knowledge of Earth’s gravity field and geoid. Instead of using state-of-the-art Earth’s gravitational field models to predict frequency shifts between distant clocks, they could permit determining geopotential differences at a centimeter-level accuracy, and question the possibility of studying geodynamic processes leading to very small vertical deformations or improve the unification of height systems. In our previous work dealing with the geopotential determination at high spatial resolution in mountainous regions, we have pointed out that clock-based geodetic observable can provide useful information at spatial scales beyond what is available from satellites and they could be used to fill areas not covered by the gravity data on the ground. Our synthetic simulations have shown that adding few clock-based potential data to a gravimetric data set can significantly improve the reconstruction of the geopotential. Therefore, it turns out there is a large variety of possible clock distribution allowing to reduce the reconstruction residuals, with different locations and number of clocks. In this work, we investigate ways to optimize clock network from a gravimetric data set in the Massif Central region in order to know where to put them to minimize the residuals and improve further the determination of the geopotential. To do that, we have used a multi-objective genetic algorithm (GA). Starting from a random initial population with different clock distributions, the algorithm selects clock locations with good chances of reproduction and reproduces the new generation of clock locations using genetic operators. The process depends on some objectives we want to reach in order to solve the optimization problem, and it is repeated several times for a given number of generations or until a solution considered as optimum is found. We show how GA can help to provide optimal solutions for a problem with a fixed and variable number of clock locations. We discuss the effect of different parameters, such as the way to define the objectives and the constrains of the problem, the quality of the clock network and the data. Numéro de notice : C2019-057 Affiliation des auteurs : Géodésie+Ext (mi2018-2019) Thématique : POSITIONNEMENT Nature : Poster nature-HAL : Poster-avec-CL DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96833 Reconciling upper mantle seismic velocity and density structure below ocean basins / Isabelle Panet (2019)PermalinkPermalinkAn analysis of gravitational gradients in rotated frames and their relation to oriented mass sources / Isabelle Panet in Journal of geophysical research : Solid Earth, vol 123 n° 12 (December 2018)PermalinkAUSGeoid2020 combined gravimetric–geometric model : location-specific uncertainties and baseline-length-dependent error decorrelation / Nicholas J. 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Klees in Journal of geodesy, vol 92 n° 4 (April 2018)PermalinkToward a global horizontal and vertical elastic load deformation model derived from GRACE and GNSS station position time series / Kristel Chanard in Journal of geophysical research : Solid Earth, vol 123 n° 4 (April 2018)PermalinkKriging and moving window kriging on a sphere in geometric (GNSS/levelling) geoid modelling / M. Ligas in Survey review, vol 50 n° 359 (March 2018)PermalinkLong-term prediction of polar motion using a combined SSA and ARMA model / Y. Shen in Journal of geodesy, vol 92 n° 3 (March 2018)PermalinkRegional geoid computation by least squares modified Hotine’s formula with additive corrections / Silja Märdla in Journal of geodesy, vol 92 n° 3 (March 2018)PermalinkHigh performance clocks and gravity field determination / Jurgen Müller in Space Science Reviews, vol 214 n° 1 (February 2018)PermalinkThe first Australian gravimetric quasigeoid model with location-specific uncertainty estimates / Will E. Featherstone in Journal of geodesy, vol 92 n° 2 (February 2018)PermalinkApplying the GOCE-based GGMs for the quasi-geoid modelling of Finland / Timo Saari in Journal of applied geodesy, vol 12 n° 1 (January 2018)PermalinkAssessing the quality of GEOID12B model through field surveys / Ahmed F. Elaksher in Journal of applied geodesy, vol 12 n° 1 (January 2018)PermalinkDéformation saisonnière de la Terre : observations, modélisations et implications / Kristel Chanard (2018)Permalink