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Integer least-squares theory for the GNSS compass / Peter J.G. Teunissen in Journal of geodesy, vol 84 n° 7 (July 2010)
[article]
Titre : Integer least-squares theory for the GNSS compass Type de document : Article/Communication Auteurs : Peter J.G. Teunissen, Auteur Année de publication : 2010 Article en page(s) : pp 433 - 447 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] altitude
[Termes IGN] ambiguïté entière
[Termes IGN] données GNSS
[Termes IGN] méthode des moindres carrés
[Termes IGN] positionnement par GNSS
[Termes IGN] résolution d'ambiguïtéRésumé : (Auteur) Global navigation satellite system (GNSS) carrier phase integer ambiguity resolution is the key to high precision positioning and attitude determination. In this contribution, we develop new integer least-squares (ILS) theory for the GNSS compass model, together with efficient integer search strategies. It extends current unconstrained ILS theory to the nonlinearly constrained case, an extension that is particularly suited for precise attitude determination. As opposed to current practice, our method does proper justice to the a priori given information. The nonlinear baseline constraint is fully integrated into the ambiguity objective function, thereby receiving a proper weighting in its minimization and providing guidance for the integer search. Different search strategies are developed to compute exact and approximate solutions of the nonlinear constrained ILS problem. Their applicability depends on the strength of the GNSS model and on the length of the baseline. Two of the presented search strategies, a global and a local one, are based on the use of an ellipsoidal search space. This has the advantage that standard methods can be applied. The global ellipsoidal search strategy is applicable to GNSS models of sufficient strength, while the local ellipsoidal search strategy is applicable to models for which the baseline lengths are not too small. We also develop search strategies for the most challenging case, namely when the curvature of the non-ellipsoidal ambiguity search space needs to be taken into account. Two such strategies are presented, an approximate one and a rigorous, somewhat more complex, one. The approximate one is applicable when the fixed baseline variance matrix is close to diagonal. Both methods make use of a search and shrink strategy. The rigorous solution is efficiently obtained by means of a search and shrink strategy that uses non quadratic, but easy-to-evaluate, bounding functions of the ambiguity objective function. The theory presented is generally valid and it is not restricted to any particular GNSS or combination of GNSSs. Its general applicability also applies to the measurement scenarios (e.g. single-epoch vs. multi-epoch, or single-frequency vs. multi-frequency). In particular it is applicable to the most challenging case of unaided, single frequency, single epoch GNSS attitude determination. The success rate performance of the different methods is also illustrated. Numéro de notice : A2010-569 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-010-0380-8 Date de publication en ligne : 02/04/2010 En ligne : https://doi.org/10.1007/s00190-010-0380-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30761
in Journal of geodesy > vol 84 n° 7 (July 2010) . - pp 433 - 447[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2010071 SL Revue Centre de documentation Revues en salle Disponible The crustal dynamics data information system: a resource to support scientific analysis using space geodesy / Carey E. Noll in Advances in space research, vol 45 n° 12 (15/06/2010)
[article]
Titre : The crustal dynamics data information system: a resource to support scientific analysis using space geodesy Type de document : Article/Communication Auteurs : Carey E. Noll, Auteur Année de publication : 2010 Article en page(s) : pp 1421 - 1440 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] déformation de la croute terrestre
[Termes IGN] données DORIS
[Termes IGN] données géodésiques
[Termes IGN] données GNSS
[Termes IGN] données ITGB
[Termes IGN] données multisources
[Termes IGN] géodésie spatiale
[Termes IGN] Global Geodetic Observing System
[Termes IGN] métadonnéesRésumé : (Auteur) Since 1982, the Crustal Dynamics Data Information System (CDDIS) has supported the archive and distribution of geodetic data products acquired by the National Aeronautics and Space Administration (NASA) as well as national and international programs. The CDDIS provides easy, timely, and reliable access to a variety of data sets, products, and information about these data. These measurements, obtained from a global network of nearly 650 instruments at more than 400 distinct sites, include DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite), GNSS (Global Navigation Satellite System), SLR and LLR (Satellite and Lunar Laser Ranging), and VLBI (Very Long Baseline Interferometry). The CDDIS data system and its archive have become increasingly important to many national and international science communities, particularly several of the operational services within the International Association of Geodesy (IAG) and its observing system the Global Geodetic Observing System (GGOS), including the International DORIS Service (IDS), the International GNSS Service (IGS), the International Laser Ranging Service (ILRS), the International VLBI Service for Geodesy and Astrometry (IVS), and the International Earth rotation and Reference frame Service (IERS). Investigations resulting from the data and products available through the CDDIS support research in many aspects of Earth system science and global change. Each month, the CDDIS archives more than one million data and derived product files totaling over 90 Gbytes in volume. In turn, the global user community downloads nearly 1.2 Tbytes (over 10.5 million files) of data and products from the CDDIS each month. The requirements of analysts have evolved since the start of the CDDIS; the specialized nature of the system accommodates the enhancements required to support diverse data sets and user needs. This paper discusses the CDDIS, including background information about the system and its user communities, archive contents, available metadata, and future plans. Numéro de notice : A2010-360 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.asr.2010.01.018 En ligne : https://doi.org/10.1016/j.asr.2010.01.018 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30554
in Advances in space research > vol 45 n° 12 (15/06/2010) . - pp 1421 - 1440[article]Assessing the accuracy of GEOID03 and GEOID09 in Connecticut / Thomas H. Meyer in SaLIS Surveying and land information science, vol 70 n° 2 (Summer 2010)
[article]
Titre : Assessing the accuracy of GEOID03 and GEOID09 in Connecticut Type de document : Article/Communication Auteurs : Thomas H. Meyer, Auteur ; Kazi Arifuzzaman, Auteur ; D. Massalski, Auteur Année de publication : 2010 Article en page(s) : pp 89 - 101 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] altitude orthométrique
[Termes IGN] Connecticut (Etats-Unis)
[Termes IGN] données GNSS
[Termes IGN] géoïde localRésumé : (Auteur) Comparing published NAVD 88 Helmert orthometric heights of First-Order bench marks against GPS-derived orthometric heights showed that GEOID03 and GEOID09 perform at their reported accuracy in Connecticut. GPS-derived orthometric heights were determined by subtracting geoid undulations from ellipsoid heights obtained from a network least-squares adjustment of GPS occupations in 2007 and 2008. A total of 73 markers were occupied in these stability classes: 25 class A, 11 class B, 12 class C, 2 class D bench marks, and 23 temporary marks with transferred elevations. Adjusted ellipsoid heights were compared against OPUS as a check. We also tested networks in which no phase-center variations were applied and in which all vectors (including "substandard" vectors) were included. Numéro de notice : A2010-403 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83714
in SaLIS Surveying and land information science > vol 70 n° 2 (Summer 2010) . - pp 89 - 101[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 121-2010021 RAB Revue Centre de documentation En réserve L003 Disponible Modélisation des retards troposphériques pour les observations GPS et impacts sur l'estimation de la hauteur ellipsoïdale / François Fund in XYZ, n° 123 (juin - août 2010)
[article]
Titre : Modélisation des retards troposphériques pour les observations GPS et impacts sur l'estimation de la hauteur ellipsoïdale Type de document : Article/Communication Auteurs : François Fund, Auteur ; Laurent Morel, Auteur ; A. Mocquet, Auteur Année de publication : 2010 Article en page(s) : pp 27 - 32 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] données GPS
[Termes IGN] données météorologiques
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] humidité de l'air
[Termes IGN] modèle atmosphérique
[Termes IGN] propagation troposphériqueRésumé : (Auteur) L'estimation d'une hauteur ellipsoïdale par GPS est connue pour être d'une précision inférieure à celles des composantes planimétriques. En première approximation, on peut l'expliquer par la couverture des satellites qui ne décrit pas complètement la géométrie du problème. Pourtant, d'autres paramètres peuvent aisément dégrader l'estimation de la hauteur. Un paramètre majeur concerne la traversée de la troposphère qui affecte radialement les observations GPS. Certes dans un contexte de positionnement différentiel à base courte de quelques kilomètres, cette problématique est largement résolue. Cependant pour le traitement précis de réseaux GPS à longues lignes de base, elle ne peut plus être négligée. Le choix de la modélisation des effets troposphériques peut alors entraîner des variations de plusieurs millimètres sur les estimations des hauteurs des stations du réseau. Les recherches menées parla communauté internationale depuis quelques décennies ont permis d'aboutir à différentes solutions de hauteur dont la précision ne cesse de s'améliorer. Numéro de notice : A2010-214 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30408
in XYZ > n° 123 (juin - août 2010) . - pp 27 - 32[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 112-2010021 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Upper mantle rheology from GRACE and GPS postseismic deformation after the 2004 Sumatra‐Andaman earthquake / Isabelle Panet in Geochemistry, Geophysics, Geosystems, vol 11 n° 6 (June 2010)
[article]
Titre : Upper mantle rheology from GRACE and GPS postseismic deformation after the 2004 Sumatra‐Andaman earthquake Type de document : Article/Communication Auteurs : Isabelle Panet , Auteur ; Fred Pollitz, Auteur ; Valentin O. Mikhailov, Auteur ; Michel Diament , Auteur ; P. Banerjee, Auteur ; K. Grijalva, Auteur Année de publication : 2010 Article en page(s) : 20 p. Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] déformation de la croute terrestre
[Termes IGN] données GPS
[Termes IGN] données GRACE
[Termes IGN] manteau terrestre
[Termes IGN] rhéologie
[Termes IGN] séisme
[Termes IGN] SumatraRésumé : (auteur) Mantle rheology is one of the essential, yet least understood, material properties of our planet, controlling the dynamic processes inside the Earth's mantle and the Earth's response to various forces. With the advent of GRACE satellite gravity, measurements of mass displacements associated with many processes are now available. In the case of mass displacements related to postseismic deformation, these data may provide new constraints on the mantle rheology. We consider the postseismic deformation due to the Mw = 9.2 Sumatra 26 December 2004 and Mw = 8.7 Nias 28 March 2005 earthquakes. Applying wavelet analyses to enhance those local signals in the GRACE time varying geoids up to September 2007, we detect a clear postseismic gravity signal. We supplement these gravity variations with GPS measurements of postseismic crustal displacements to constrain postseismic relaxation processes throughout the upper mantle. The observed GPS displacements and gravity variations are well explained by a model of viscoelastic relaxation plus a small amount of afterslip at the downdip extension of the coseismically ruptured fault planes. Our model uses a 60 km thick elastic layer above a viscoelastic asthenosphere with Burgers body rheology. The mantle below depth 220 km has a Maxwell rheology. Assuming a low transient viscosity in the 60–220 km depth range, the GRACE data are best explained by a constant steady state viscosity throughout the ductile portion of the upper mantle (e.g., 60–660 km). This suggests that the localization of relatively low viscosity in the asthenosphere is chiefly in the transient viscosity rather than the steady state viscosity. We find a 8.1018 Pa s mantle viscosity in the 220–660 km depth range. This may indicate a transient response of the upper mantle to the high amount of stress released by the earthquakes. To fit the remaining misfit to the GRACE data, larger at the smaller spatial scales, cumulative afterslip of about 75 cm at depth should be added over the period spanned by the GRACE models. It produces only small crustal displacements. Our results confirm that satellite gravity data are an essential complement to ground geodetic and geophysical networks in order to understand the seismic cycle and the Earth's inner structure. Numéro de notice : A2010-655 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1029/2009GC002905 Date de publication en ligne : 19/06/2010 En ligne : https://doi.org/10.1029/2009GC002905 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91728
in Geochemistry, Geophysics, Geosystems > vol 11 n° 6 (June 2010) . - 20 p.[article]Documents numériques
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