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Hydrological excitation of polar motion by different variables from the GLDAS models / Malgorzata Winska in Journal of geodesy, vol 91 n° 12 (December 2017)
[article]
Titre : Hydrological excitation of polar motion by different variables from the GLDAS models Type de document : Article/Communication Auteurs : Malgorzata Winska, Auteur ; Jolanta Nastula, Auteur ; David A. Salstein, Auteur Année de publication : 2017 Article en page(s) : pp 1461 - 1473 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] données GRACE
[Termes IGN] moment cinétique
[Termes IGN] mouvement du pôle
[Termes IGN] surcharge hydrologiqueMots-clés libres : Global Land Data Assimilation System model GLDAS model Résumé : (Auteur) Continental hydrological loading by land water, snow and ice is a process that is important for the full understanding of the excitation of polar motion. In this study, we compute different estimations of hydrological excitation functions of polar motion (as hydrological angular momentum, HAM) using various variables from the Global Land Data Assimilation System (GLDAS) models of the land-based hydrosphere. The main aim of this study is to show the influence of variables from different hydrological processes including evapotranspiration, runoff, snowmelt and soil moisture, on polar motion excitations at annual and short-term timescales. Hydrological excitation functions of polar motion are determined using selected variables of these GLDAS realizations. Furthermore, we use time-variable gravity field solutions from the Gravity Recovery and Climate Experiment (GRACE) to determine the hydrological mass effects on polar motion excitation. We first conduct an intercomparison of the maps of variations of regional hydrological excitation functions, timing and phase diagrams of different regional and global HAMs. Next, we estimate the hydrological signal in geodetically observed polar motion excitation as a residual by subtracting the contributions of atmospheric angular momentum and oceanic angular momentum. Finally, the hydrological excitations are compared with those hydrological signals determined from residuals of the observed polar motion excitation series. The results will help us understand the relative importance of polar motion excitation within the individual hydrological processes, based on hydrological modeling. This method will allow us to estimate how well the polar motion excitation budget in the seasonal and inter-annual spectral ranges can be closed. Numéro de notice : A2017-708 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1036-8 En ligne : https://doi.org/10.1007/s00190-017-1036-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88089
in Journal of geodesy > vol 91 n° 12 (December 2017) . - pp 1461 - 1473[article]New adjustment of the Croatian first order gravity network / Marija Repanic in Geodetski vestnik, vol 61 n° 4 (December 2017 - February 2018)
[article]
Titre : New adjustment of the Croatian first order gravity network Type de document : Article/Communication Auteurs : Marija Repanic, Auteur Année de publication : 2017 Article en page(s) : pp 630 - 648 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] compensation
[Termes IGN] constante
[Termes IGN] Croatie
[Termes IGN] erreur instrumentale
[Termes IGN] étalonnage d'instrument
[Termes IGN] réseau de premier ordre
[Termes IGN] réseau gravimétrique localRésumé : (Auteur) The paper presents the new joint adjustment of the Croatian First Order Gravity Network, for the first time adjusted as a whole. The adjustment involves absolute and relative gravity measurements, latter performed in the course of four survey stages. Firstly, the measurements are concisely described. Revision of the absolute and pre-processing of the relative measurements are briefly presented. The applied adjustment model is described. Accordingly, the gravity values of all stations (absolute and relative), corrections of linear calibration coefficient and linear drift coefficients are included in the functional model as unknown parameters. The absolute measurements are included in the adjustment as observations. The new adjustment resulted in significantly different gravity values as compared to previous adjustments (of individual stages of the network). The differences in gravity values are an order of magnitude greater than the expected accuracy. It is shown that the differences are mainly due to the errors in the gravimeters’ calibration constants, which were neglected in the previous adjustments. Because of the significant differences, the new linear transformation function from the Potsdam to the Croatian Gravity System is determined. Numéro de notice : A2017-778 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.15292/geodetski-vestnik.2017.04.630-648 En ligne : http://www.geodetski-vestnik.com/61/4/gv61-4_repanic.pdf Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88984
in Geodetski vestnik > vol 61 n° 4 (December 2017 - February 2018) . - pp 630 - 648[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 139-2017041 RAB Revue Centre de documentation En réserve L003 Disponible On the estimation of physical height changes using GRACE satellite mission data – A case study of Central Europe / Walyeldeen Godah in Geodesy and cartography, vol 66 n° 2 (December 2017)
[article]
Titre : On the estimation of physical height changes using GRACE satellite mission data – A case study of Central Europe Type de document : Article/Communication Auteurs : Walyeldeen Godah, Auteur ; Malgorzata Szelachowska, Auteur ; Jan Krynski, Auteur Année de publication : 2017 Article en page(s) : pp 211 - 226 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] altitude orthométrique
[Termes IGN] analyse en composantes principales
[Termes IGN] données GRACE
[Termes IGN] Europe centrale
[Termes IGN] modèle de géopotentiel
[Termes IGN] variation saisonnièreRésumé : (auteur) The dedicated gravity satellite missions, in particular the GRACE (Gravity Recovery and Climate Experiment) mission launched in 2002, provide unique data for studying temporal variations of mass distribution in the Earth’s system, and thereby, the geometry and the gravity field changes of the Earth. The main objective of this contribution is to estimate physical height (e.g. the orthometric/normal height) changes over Central Europe using GRACE satellite mission data as well as to analyse them and model over the selected study area. Physical height changes were estimated from temporal variations of height anomalies and vertical displacements of the Earth surface being determined over the investigated area. The release 5 (RL05) GRACE-based global geopotential models as well as load Love numbers from the Preliminary Reference Earth Model (PREM) were used as input data. Analysis of the estimated physical height changes and their modelling were performed using two methods: the seasonal decomposition method and the PCA/ EOF (Principal Component Analysis/Empirical Orthogonal Function) method and the differences obtained were discussed. The main findings reveal that physical height changes over the selected study area reach up to 22.8 mm. The obtained physical height changes can be modelled with an accuracy of 1.4 mm using the seasonal decomposition method. Numéro de notice : A2017-788 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/geocart-2017-0013 En ligne : https://doi.org/10.1515/geocart-2017-0013 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89100
in Geodesy and cartography > vol 66 n° 2 (December 2017) . - pp 211 - 226[article]Basic Earth's Parameters as estimated from VLBI observations / Ping Zhu in Geodesy and Geodynamics, vol 8 n° 6 (November 2017)
[article]
Titre : Basic Earth's Parameters as estimated from VLBI observations Type de document : Article/Communication Auteurs : Ping Zhu, Auteur ; Attilio Rivoldini, Auteur ; Laurence Koot, Auteur ; Véronique Dehant, Auteur Année de publication : 2017 Article en page(s) : pp 427 - 432 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse diachronique
[Termes IGN] données ITGB
[Termes IGN] interférométrie à très grande base
[Termes IGN] nutation
[Termes IGN] série temporelleRésumé : (auteur) The global Very Long Baseline Interferometry observation for measuring the Earth rotation's parameters was launched around 1970s. Since then the precision of the measurements is continuously improving by taking into account various instrumental and environmental effects. The MHB2000 nutation model was introduced in 2002, which is constructed based on a revised nutation series derived from 20 years VLBI observations (1980–1999). In this work, we firstly estimated the amplitudes of all nutation terms from the IERS-EOP-C04 VLBI global solutions w.r.t. IAU1980, then we further inferred the BEPs (Basic Earth's Parameters) by fitting the major nutation terms. Meanwhile, the BEPs were obtained from the same nutation time series using a BI (Bayesian Inversion). The corrections to the precession rate and the estimated BEPs are in an agreement, independent of which methods have been applied. Numéro de notice : A2017-790 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1016/j.geog.2017.04.007 En ligne : https://doi.org/10.1016/j.geog.2017.04.007 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89053
in Geodesy and Geodynamics > vol 8 n° 6 (November 2017) . - pp 427 - 432[article]On the equivalence of spherical splines with least-squares collocation and Stokes’s formula for regional geoid computation / Vegard Ophaug in Journal of geodesy, vol 91 n° 11 (November 2017)
[article]
Titre : On the equivalence of spherical splines with least-squares collocation and Stokes’s formula for regional geoid computation Type de document : Article/Communication Auteurs : Vegard Ophaug, Auteur ; Christian Gerlach, Auteur Année de publication : 2017 Article en page(s) : pp 1367 - 1382 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse comparative
[Termes IGN] collocation par moindres carrés
[Termes IGN] fonction de base radiale
[Termes IGN] fonction spline
[Termes IGN] formule de Stokes
[Termes IGN] géoïde local
[Termes IGN] précision millimétriqueRésumé : (Auteur) This work is an investigation of three methods for regional geoid computation: Stokes’s formula, least-squares collocation (LSC), and spherical radial base functions (RBFs) using the spline kernel (SK). It is a first attempt to compare the three methods theoretically and numerically in a unified framework. While Stokes integration and LSC may be regarded as classic methods for regional geoid computation, RBFs may still be regarded as a modern approach. All methods are theoretically equal when applied globally, and we therefore expect them to give comparable results in regional applications. However, it has been shown by de Min (Bull Géod 69:223–232, 1995. doi:10.1007/BF00806734) that the equivalence of Stokes’s formula and LSC does not hold in regional applications without modifying the cross-covariance function. In order to make all methods comparable in regional applications, the corresponding modification has been introduced also in the SK. Ultimately, we present numerical examples comparing Stokes’s formula, LSC, and SKs in a closed-loop environment using synthetic noise-free data, to verify their equivalence. All agree on the millimeter level. Numéro de notice : A2017-707 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1030-1 En ligne : https://doi.org/10.1007/s00190-017-1030-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88088
in Journal of geodesy > vol 91 n° 11 (November 2017) . - pp 1367 - 1382[article]Seasonal low-degree changes in terrestrial water mass load from global GNSS measurements / Thierry Meyrath in Journal of geodesy, vol 91 n° 11 (November 2017)PermalinkExperiences with the QDaedalus system for astrogeodetic determination of deflections of the vertical / Markus Hauk in Survey review, vol 49 n° 355 (October 2017)PermalinkThe relation between degree-2160 spectral models of Earth’s gravitational and topographic potential : a guide on global correlation measures and their dependency on approximation effects / Christian Hirt in Journal of geodesy, vol 91 n° 10 (October 2017)PermalinkAnalysis of decade-long time series of GPS-based polar motion estimates at 15-min temporal resolution / Aurore E. Sibois in Journal of geodesy, vol 91 n° 8 (August 2017)PermalinkDetermination of a high spatial resolution geopotential model using atomic clock comparisons / Guillaume Lion in Journal of geodesy, vol 91 n° 6 (June 2017)PermalinkImprovements in precise orbits of altimetry satellites and their impact on mean sea level monitoring / Sergei Rudenko in IEEE Transactions on geoscience and remote sensing, vol 55 n° 6 (June 2017)PermalinkMulti-scale modeling of Earth's gravity field in space and time / Shuo (2) Wang in Journal of geodynamics, vol 106 (May 2017)PermalinkSpace-wise approach for airborne gravity data modelling / Daniele Sampietro in Journal of geodesy, vol 91 n° 5 (May 2017)PermalinkCalcul du quasi-géoïde QGF16 et de la grille de conversion altimétrique RAF16 : état d'avancement et perspectives / François L'écu in XYZ, n° 150 (mars - mai 2017)PermalinkLe chemin vers un système de référence altimétrique global et unifié / Laura Sánchez in XYZ, n° 150 (mars - mai 2017)Permalink