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Auteur J. Kusche |
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Comparisons of atmospheric mass variations derived from ECMWF reanalysis and operational fields, over 2003–2011 / E. Forootan in Journal of geodesy, vol 88 n° 5 (May 2014)
[article]
Titre : Comparisons of atmospheric mass variations derived from ECMWF reanalysis and operational fields, over 2003–2011 Type de document : Article/Communication Auteurs : E. Forootan, Auteur ; Olga Didova, Auteur ; M. Schumacher, Auteur ; J. Kusche, Auteur ; B. Elsaka, Auteur Année de publication : 2014 Article en page(s) : pp 503 - 514 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] analyse diachronique
[Termes IGN] atmosphère terrestre
[Termes IGN] données GRACE
[Termes IGN] levé gravimétrique
[Termes IGN] masse d'air
[Termes IGN] variationRésumé : (Auteur) There are two spurious jumps in the atmospheric part of the Gravity Recovery and Climate Experiment-Atmosphere and Ocean De-aliasing level 1B (GRACE-AOD1B) products, which occurred in January-February of the years 2006 and 2010, as a result of the vertical level and horizontal resolution changes in the ECMWFop (European Centre for Medium-Range Weather Forecasts operational analysis). These jumps cause a systematic error in the estimation of mass changes from GRACE time-variable level 2 products, since GRACE-AOD1B mass variations are removed during the computation of GRACE level 2. In this short note, the potential impact of using an improved set of 6-hourly atmospheric de-aliasing products on the computations of linear trends as well as the amplitude of annual and semi-annual mass changes from GRACE is assessed. These improvements result from 1) employing a modified 3D integration approach (ITG3D), and 2) using long-term consistent atmospheric fields from the ECMWF reanalysis (ERA-Interim). The monthly averages of the new ITG3D-ERA-Interim de-aliasing products are then compared to the atmospheric part of GRACE-AOD1B, covering January 2003 to December 2010. These comparisons include the 33 world largest river basins along with Greenland and Antarctica ice sheets. The results indicate a considerable difference in total atmospheric mass derived from the two products over some of the mentioned regions. We suggest that future GRACE studies consider these through updating uncertainty budgets or by applying corrections to estimated trends and amplitudes/phases Numéro de notice : A2014-258 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0696-x Date de publication en ligne : 07/02/2014 En ligne : https://doi.org/10.1007/s00190-014-0696-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33161
in Journal of geodesy > vol 88 n° 5 (May 2014) . - pp 503 - 514[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2014051 SL Revue Centre de documentation Revues en salle Disponible Separation of global time-variable gravity signals into maximally independent components / E. Forootan in Journal of geodesy, vol 86 n° 7 (July 2012)
[article]
Titre : Separation of global time-variable gravity signals into maximally independent components Type de document : Article/Communication Auteurs : E. Forootan, Auteur ; J. Kusche, Auteur Année de publication : 2012 Article en page(s) : pp 477 - 497 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse en composantes indépendantes
[Termes IGN] analyse en composantes principales
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] données GRACE
[Termes IGN] filtrage du signal
[Termes IGN] traitement de donnéesRésumé : (Auteur) The Gravity Recovery and Climate Experiment (GRACE) products provide valuable information about total water storage variations over the whole globe. Since GRACE detects mass variations integrated over vertical columns, it is desirable to separate its total water storage anomalies into their original sources. Among the statistical approaches, the principal component analysis (PCA) method and its extensions have been frequently proposed to decompose the GRACE products into space and time components. However, these methods only search for decorrelated components that on the one hand are not always interpretable and on the other hand often contain a superposition of independent source signals. In contrast, independent component analysis (ICA) represents a technique that separates components based on assumed statistical independence using higher-order statistical information. If one assumes that independent physical processes generate statistically independent signal components added up in the GRACE observations, separating them by ICA is a reliable strategy to identify these processes. In this paper, the performance of the conventional PCA, its rotated extension and ICA are investigated when applied to the GRACE-derived total water storage variations. These analyses have been tested on both a synthetic example and on the real GRACE level-2 monthly solutions derived from GeoForschungsZentrum Potsdam (GFZ RL04) and Bonn University (ITG2010). Within the synthetic example, we can show how imposing statistical independence in the framework of ICA improves the extraction of the ‘original’ signals from a GRACE-type superposition. We are therefore confident that also for the real case the ICA algorithm, without making prior assumptions about the long-term behaviour or on the frequencies contained in the signal, improves over the performance of PCA and its rotated extension in the separation of periodical and long-term components. Numéro de notice : A2012-355 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0532-5 Date de publication en ligne : 22/11/2011 En ligne : https://doi.org/10.1007/s00190-011-0532-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31801
in Journal of geodesy > vol 86 n° 7 (July 2012) . - pp 477 - 497[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2012071 RAB Revue Centre de documentation En réserve L003 Disponible vol 81 n° 1 - January 2007 - Satellite gravimetry and inverse problems (Bulletin de Journal of geodesy) / Nico Sneeuw
[n° ou bulletin]
Titre : vol 81 n° 1 - January 2007 - Satellite gravimetry and inverse problems Type de document : Périodique Auteurs : Nico Sneeuw, Éditeur scientifique ; J. Kusche, Éditeur scientifique ; International association of geodesy, Auteur Année de publication : 2007 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie
[Termes IGN] gravimétrie spatiale
[Termes IGN] problème inverseNuméro de notice : 266-0701 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Numéro de périodique Permalink : https://documentation.ensg.eu/index.php?lvl=bulletin_display&id=11610 [n° ou bulletin]Contient
- Wavelet modeling of regional and temporal variations of the Earth’s gravitational potential observed by GRACE / M.J. Fengler in Journal of geodesy, vol 81 n° 1 (January 2007)
- Local solutions to inverse problems in geodesy: The impact of the noise covariance structure upon the accuracy of estimation / F. Bauer in Journal of geodesy, vol 81 n° 1 (January 2007)
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Code-barres Cote Support Localisation Section Disponibilité 266-07011 RAB Revue Centre de documentation En réserve L003 Disponible 266-07012 RAB Revue Centre de documentation En réserve L003 Disponible Inverse Probleme bei der Gravitationsfelsbestimmung mittels SST- und SGG-Satellitenmissionen Darstellungen / J. Kusche (2002)
Titre : Inverse Probleme bei der Gravitationsfelsbestimmung mittels SST- und SGG-Satellitenmissionen Darstellungen Titre original : [Problème inverse lors de la détermination du champ de gravitation au moyen des missions satellitaires SST et SGG] Type de document : Thèse/HDR Auteurs : J. Kusche, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 2002 Collection : DGK - C Sous-collection : Dissertationen num. 548 Importance : 79 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-7696-9585-4 Note générale : Bibliographie Langues : Allemand (ger) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de gravitation
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] covariance
[Termes IGN] fonction spline
[Termes IGN] gradiométrie
[Termes IGN] itération
[Termes IGN] méthode des moindres carrés
[Termes IGN] mission spatiale
[Termes IGN] problème inverseIndex. décimale : 30.40 Géodésie physique Résumé : (Auteur) We investigate certain problems of downward continuation, which arise in the context of modern SST- and SGG-satellite missions designed for geopotential field recovery, in a generalized context. Fast solution techniques are presented and analyzed.
First the mathematical foundations of the treatment of inverse and ill-posed problems are reviewed. Then we begin with the definition of SST and SGG model problems, whose ill-posedness or, more precisely, ill-conditioning will be quantified using the spectrum of the normal equations. Different representations of the anomalous gravity field lead to different degrees of ill-conditioning. Our focus is oil representation techniques with space-localizing properties, rather than studying the familiar frequency-localizing spherical harmonics. Tykhonov-regularization as an essential tool for computing reasonable solutions in ill-posed problems is extensively studied within this thesis, including the implementation of a posteriori strategies for the determination of the regularization parameter.
After that we consider iterative methods for the solution of the regularized normal equations, which emerge from Galerkin discretizations. Two of the fastest techniques - conjugate gradients and multigrid iterations are presented first within an abstract setting, but in the sequel we give matrix algorithms for multigrid standalone iteration as well as multigrid preconditioning for CG. For the first time in this application, convergence properties are evaluated theoretically using the model problems. Finally, we consider the implementation of a posteriori parameter choice rules for Tykhonov-regularization in the framework of our iterative solvers.Numéro de notice : 13098 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Thèse étrangère Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54881 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 13098-01 30.40 Livre Centre de documentation Géodésie Disponible 13098-02 30.40 Livre Centre de documentation Géodésie Disponible Relativistic modeling for geodetic experiments in local spacetimes / J. Kusche (1996)
Titre : Relativistic modeling for geodetic experiments in local spacetimes Type de document : Monographie Auteurs : J. Kusche, Auteur Editeur : Munich : Bayerische Akademie der Wissenschaften Année de publication : 1996 Collection : DGK - A Sous-collection : Theoretische Geodäsie num. 110 Importance : 35 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 3-7696-9192-4 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie
[Termes IGN] espace-temps
[Termes IGN] relativité généraleIndex. décimale : 30.00 Géodésie - généralités Résumé : (Auteur) This paper deals with the embedding of geodetic experiments into a relativistic framework. It covers the introduction and handling of local coordinate systems and tetrads on a Post-Newtonian "back-ground" metric, which may be that of a rotating earthbound coordinate system. These concepts are applied to gravimetry, satellite gradiometry, and satellite-to-satellite-tracking. Numéro de notice : 28246 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Monographie Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=63592 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 28246-01 30.00 Livre Centre de documentation Géodésie Disponible Ein Modell für die hochgenaue Navigation autonomer flächenbeweglicher Fahrzeuge / J. Kusche (1994)Permalink