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Improving the estimation of fractional-cycle biases for ambiguity resolution in precise point positioning / J. Geng in Journal of geodesy, vol 86 n° 8 (August 2012)
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Titre : Improving the estimation of fractional-cycle biases for ambiguity resolution in precise point positioning Type de document : Article/Communication Auteurs : J. Geng, Auteur ; C. Shi, Auteur ; M. Ge, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 579 - 589 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] données GPS
[Termes IGN] erreur systématique
[Termes IGN] positionnement ponctuel précis
[Termes IGN] résolution d'ambiguïtéRésumé : (Auteur) Ambiguity resolution dedicated to a single global positioning system (GPS) station can improve the accuracy of precise point positioning. In this process, the estimation accuracy of the narrow-lane fractional-cycle biases (FCBs), which destroy the integer nature of undifferenced ambiguities, is crucial to the ambiguity-fixed positioning accuracy. In this study, we hence propose the improved narrow-lane FCBs derived from an ambiguity-fixed GPS network solution, rather than the original (i.e. previously proposed) FCBs derived from an ambiguity-float network solution. The improved FCBs outperform the original FCBs by ensuring that the resulting ambiguity-fixed daily positions coincide in nature with the state-of-the-art positions generated by the International GNSS Service (IGS). To verify this improvement, 1 year of GPS measurements from about 350 globally distributed stations were processed. We find that the original FCBs differ more from the improved FCBs when fewer stations are involved in the FCB estimation, especially when the number of stations is less than 20. Moreover, when comparing the ambiguity-fixed daily positions with the IGS weekly positions for 248 stations through a Helmert transformation, for the East component, we find that on 359 days of the year the daily RMS of the transformed residuals based on the improved FCBs is smaller by up to 0.8 mm than those based on the original FCBs, and the mean RMS over the year falls evidently from 2.6 to 2.2 mm. Meanwhile, when using the improved rather than the original FCBs, the RMS of the transformed residuals for the East component of 239 stations (i.e. 96.4% of all 248 stations) is clearly reduced by up to 1.6 mm, especially for stations located within a sparse GPS network. Therefore, we suggest that narrow-lane FCBs should be determined with ambiguity-fixed, rather than ambiguity-float, GPS network solutions. Numéro de notice : A2012-374 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0537-0 Date de publication en ligne : 14/12/2011 En ligne : https://doi.org/10.1007/s00190-011-0537-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31820
in Journal of geodesy > vol 86 n° 8 (August 2012) . - pp 579 - 589[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2012081 RAB Revue Centre de documentation En réserve L003 Disponible Land water storage changes from ground and space geodesy : first results from the GHYRAF (Gravity and Hydrology in Africa) experiment / Jacques Hinderer in Pure and applied geophysics, vol 169 n° 8 (August 2012)
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Titre : Land water storage changes from ground and space geodesy : first results from the GHYRAF (Gravity and Hydrology in Africa) experiment Type de document : Article/Communication Auteurs : Jacques Hinderer, Auteur ; Jeffrey Pfeffer, Auteur ; M. Boucher, Auteur ; Samuel Nahmani , Auteur ; Caroline de Linage, Auteur ; Jean-Paul Boy, Auteur ; Pierre Genthon, Auteur ; Luc Séguis, Auteur ; G. Favreau, Auteur ; Olivier Bock
, Auteur ; M. Descloitres, Auteur
Année de publication : 2012 Article en page(s) : pp 1391 - 1410 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] Afrique occidentale
[Termes IGN] Bénin
[Termes IGN] cycle climatique
[Termes IGN] données GPS
[Termes IGN] données GRACE
[Termes IGN] données météorologiques
[Termes IGN] levé gravimétrique
[Termes IGN] modèle hydrographique
[Termes IGN] mousson
[Termes IGN] Niamey (Niger)
[Termes IGN] précipitation
[Termes IGN] Tamanghasset (Algérie)Mots-clés libres : Gravity and Hydrology in Africa Résumé : (Auteur) This paper is devoted to the first results from the GHYRAF (Gravity and Hydrology in Africa) experiment conducted since 2008 in West Africa and is aimed at investigating the changes in water storage in different regions sampling a strong rainfall gradient from the Sahara to the monsoon zone. The analysis of GPS vertical displacement in Niamey (Niger) and Djougou (Benin) shows that there is a clear annual signature of the hydrological load in agreement with global hydrology models like GLDAS. The comparison of GRACE solutions in West Africa, and more specifically in the Niger and Lake Chad basins, reveals a good agreement for the large scale annual water storage changes between global hydrology models and space gravity observations. Ground gravity observations done with an FG5 absolute gravimeter also show signals which can be well related to measured changes in soil and ground water. We present the first results for two sites in the Sahelian band (Wankama and Diffa in Niger) and one (Djougou in Benin) in the Sudanian monsoon region related to the recharge–discharge processes due to the monsoonal event in summer 2008 and the following dry season. It is confirmed that ground gravimetry is a useful tool to constrain local water storage changes when associated to hydrological and subsurface geophysical in situ measurements. Numéro de notice : A2012-739 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00024-011-0417-9 Date de publication en ligne : 14/10/2011 En ligne : https://doi.org/10.1007/s00024-011-0417-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91472
in Pure and applied geophysics > vol 169 n° 8 (August 2012) . - pp 1391 - 1410[article]Monitoring GOCE gradiometer calibration parameters using accelerometer and star sensor data: methodology and first results / C. Siemes in Journal of geodesy, vol 86 n° 8 (August 2012)
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Titre : Monitoring GOCE gradiometer calibration parameters using accelerometer and star sensor data: methodology and first results Type de document : Article/Communication Auteurs : C. Siemes, Auteur ; Roger Haagmans, Auteur ; M. Kern, Auteur ; et al., Auteur Année de publication : 2012 Article en page(s) : pp 629 - 645 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] champ de pesanteur terrestre
[Termes IGN] données GOCE
[Termes IGN] étalonnage d'instrument
[Termes IGN] GOCE
[Termes IGN] gradient de gravitation
[Termes IGN] gradiomètre
[Termes IGN] série temporelleRésumé : (Auteur) The Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite, launched on 17 March 2009, is designed to measure the Earth’s mean gravity field with unprecedented accuracy at spatial resolutions down to 100 km. The accurate calibration of the gravity gradiometer on-board GOCE is of utmost importance for achieving the mission goals. ESA’s baseline method for the calibration uses star sensor and accelerometer data of a dedicated calibration procedure, which is executed every 2 months. In this paper, we describe a method for monitoring the evolution of calibration parameter during that time. The method works with star sensor and accelerometer data and does not require gravity field models, which distinguishes it from other existing methods. We present time series of calibration parameters estimated from GOCE data from 1 November 2009 to 17 May 2010. The time series confirm drifts in the calibration parameters that are present in the results of other methods, including ESA’s baseline method. Although these drifts are very small, they degrade the gravity gradients, leading to the conclusion that the calibration parameters of the ESA’s baseline method need to be linearly interpolated. Further, we find a correction of -36 * 10-6 for one calibration parameter (in-line differential scale factor of the cross-track gradiometer arm), which improves the gravity gradient performance. The results are validated by investigating the trace of the calibrated gravity gradients and comparing calibrated gravity gradients with reference gradients computed along the GOCE orbit using the ITG-Grace-2010s gravity field model. Numéro de notice : A2012-376 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-012-0545-8 Date de publication en ligne : 22/02/2012 En ligne : https://doi.org/10.1007/s00190-012-0545-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31822
in Journal of geodesy > vol 86 n° 8 (August 2012) . - pp 629 - 645[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2012081 RAB Revue Centre de documentation En réserve L003 Disponible Multidirectional visibility index for analytical shading enhancement / T. Podobnikar in Cartographic journal (the), vol 49 n° 3 (August 2012)
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Titre : Multidirectional visibility index for analytical shading enhancement Type de document : Article/Communication Auteurs : T. Podobnikar, Auteur Année de publication : 2012 Article en page(s) : pp 195 - 207 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] azimut
[Termes IGN] estompage
[Termes IGN] méthode robuste
[Termes IGN] modèle numérique de surface
[Termes IGN] ombre
[Termes IGN] pente
[Termes IGN] relief
[Termes IGN] visibilité
[Termes IGN] visualisation 3DRésumé : (Auteur) A novel method called multidirectional visibility index (MVI) has been developed and verified. The MVI improves standard cartographic analytical shading with a number of enhancements to topographic detail and prominent structures, i.e. the portrayal of flat areas in lighter tones, the accentuation of morphologic edges, and the multiscale visualisation of morphologic terrain features. The procedure requires a digital elevation model (DEM) and involves the following steps: visibility mask computation; the respective multidirectional altering of the azimuth and elevation angle; the generation of continuous grid MVIs that indicate upper/lower views, quasi-slope, and relative relief; and an appropriate visualisation of the relevant MVI as a standalone technique or in combination with standard hill-shaded relief. The modelling parameters are robust and therefore highly adaptive to different landforms. Numéro de notice : A2012-535 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/1743277412Y.0000000012 Date de publication en ligne : 22/11/2013 En ligne : https://doi.org/10.1179/1743277412Y.0000000012 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31981
in Cartographic journal (the) > vol 49 n° 3 (August 2012) . - pp 195 - 207[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 030-2012031 RAB Revue Centre de documentation En réserve L003 Disponible Optimal regularization for geopotential model GOCO02S by Monte Carlo methods and multi-scale representation of density anomalies / Karl Rudolf Koch in Journal of geodesy, vol 86 n° 8 (August 2012)
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Titre : Optimal regularization for geopotential model GOCO02S by Monte Carlo methods and multi-scale representation of density anomalies Type de document : Article/Communication Auteurs : Karl Rudolf Koch, Auteur ; J. Brockmann, Auteur ; W.D. Schuh, Auteur Année de publication : 2012 Article en page(s) : pp 647 - 660 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] analyse de variance
[Termes IGN] B-Spline
[Termes IGN] données GOCE
[Termes IGN] méthode de Monte-Carlo
[Termes IGN] modèle de géopotentiel
[Termes IGN] ondeletteRésumé : (Auteur) GOCO02S is a combined satellite-only geopotential model, regularized from degrees 180 to 250 of the expansion into spherical harmonics. To investigate the start of the regularization, the normal equations of GOCO02S have been used to compute additional geopotential models by regularizations beginning at degrees 160, 200, 220 and with no regularization. Three different methods are applied to determine where to start the regularization. The simplest one considers the decrease of the degree variances of the not regularized solution. The second one tests for the same solution the hypothesis that the square root of the degree variance is equal to the value computed by the estimated harmonic coefficients. If the hypothesis has to be rejected for a certain degree, the error degree variance is so large that the estimated harmonic coefficients cannot be trusted anymore so that the regularization has to start at that degree. The third method uses the density anomalies by which the disturbing potential is caused resulting from the geopotential model. The density anomalies are well suited to visualize the effects of the higher degree harmonics. In contrast to the base functions of the harmonic coefficients with global support, the density anomalies are expressed by a B-spline surface with local support. Multi-scale representations were applied and the hypotheses tested that the wavelet coefficients are equal to zero. Accepting the hypotheses means that nonsignificant wavelet coefficients were determined which lead to nonsignificant density anomalies. By comparing these anomalies for different regularizations, the degree where to start the regularization is determined. It turns out that beginning the regularization at degree 180, as was done for GOCO02S, is a correct choice. Numéro de notice : A2012-377 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-012-0546-7 Date de publication en ligne : 24/02/2012 En ligne : https://doi.org/10.1007/s00190-012-0546-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31823
in Journal of geodesy > vol 86 n° 8 (August 2012) . - pp 647 - 660[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 266-2012081 RAB Revue Centre de documentation En réserve L003 Disponible Space weather and the Australian ionospheric prediction service: ready for the Solar Max 2012 / Dave Neudegg in Space research today, n° 184 (01/08/2012)
PermalinkThe spherical Slepian basis as a means to obtain spectral consistency between mean sea level and the geoid / D. Slobbe in Journal of geodesy, vol 86 n° 8 (August 2012)
PermalinkTotal least squares adjustment in partial errors-in-variables models: algorithm and statistical analysis / P. Xu in Journal of geodesy, vol 86 n° 8 (August 2012)
Permalink100 ans de mensuration officielle : synergies avec les améliorations structurelles. Exemples tirés de la pratique du canton de Thurgovie / A. Stübi in Géomatique suisse, vol 110 n° 7 (01/07/2012)
PermalinkBasic equations for constructing geopotential models from the gravitational potential derivatives of the first and second orders in the terrestrial reference frame / M. Petrovskaya in Journal of geodesy, vol 86 n° 7 (July 2012)
PermalinkITRF2008 plate motion model / Zuheir Altamimi in Journal of geophysical research : Solid Earth, Vol 117 n° B7 (July 2012)
PermalinkLa mensuration officielle suisse : une centenaire qui se porte bien / Hervé Halbout in Géomatique expert, n° 87 (01/07/2012)
PermalinkPositional accuracy improvement using empirical analytic functions / C. Lopez-Vasquez in Cartography and Geographic Information Science, vol 39 n° 3 (July 2012)
PermalinkSeparation of global time-variable gravity signals into maximally independent components / E. Forootan in Journal of geodesy, vol 86 n° 7 (July 2012)
PermalinkThe affine constrained GNSS attitude model and its multivariate integer least-squares solution / Peter J.G. Teunissen in Journal of geodesy, vol 86 n° 7 (July 2012)
Permalink150 years of international cooperation in geodesy: precursors and development of Baeyer's project to a scientific organisation / Wolfgang Torge in ZFV, Zeitschrift für Geodäsie, Geoinformation und Landmanagement, vol 137 n° 3 (01/06/2012)
PermalinkAnalysis of 4 years (2002-2005) of laser data on Starlette, Stella and LAGEOS-1/2 satellites for stations coordinates and Earth orientations parameters (EOP) / Bachir Gourine in Bulletin des sciences géographiques, n° 27 (juin 2012)
PermalinkAssessment of the GOCE-based global gravity models in Canada / Elmas Sinem Ince in Geomatica, vol 66 n° 2 (June 2012)
PermalinkChoix d'un modèle géopotentiel global pour la détermination du géoïde en Algérie / N. Rabehi in Bulletin des sciences géographiques, n° 27 (juin 2012)
PermalinkComing Soon: the international GNSS real-time service / M. Caissy in GPS world, vol 23 n° 6 (June 2012)
PermalinkCurrent activities of International Association of Geodesy (IAG) as the successor organisation of the Mitteleuropäische Gradmessung / Hermann Drewes in ZFV, Zeitschrift für Geodäsie, Geoinformation und Landmanagement, vol 137 n° 3 (01/06/2012)
PermalinkEinsatz der Atominterferometrie in der Geodäsie / M. Schilling in ZFV, Zeitschrift für Geodäsie, Geoinformation und Landmanagement, vol 137 n° 3 (01/06/2012)
PermalinkEstimation of the zero-height geopotential level WoLVD in a local vertical datum from inversion of co-located GPS, leveling and geoid heights: a case study in the Hellenic islands / Christopher Kotsakis in Journal of geodesy, vol 86 n° 6 (June 2012)
PermalinkPermalinkPermalinkOn the detectability of synthetic disturbances in FG5 absolute gravimetry data using lomb-scargle analysis / M. Orlob in Geomatica, vol 66 n° 2 (June 2012)
PermalinkRecent developments in Precise Point Positioning / Sunil Bisnath in Geomatica, vol 66 n° 2 (June 2012)
PermalinkThe effect of using inconsistent ocean tidal loading models on GPS coordinate solutions / Y. Fu in Journal of geodesy, vol 86 n° 6 (June 2012)
PermalinkWavelet‐based directional analysis of the gravity field : evidence for large‐scale undulations / M. Hayn in Geophysical journal international, vol 189 n° 3 (June 2012)
PermalinkA ‘devious course’ : projecting toleration on Mercator’s ‘map of the world’, 1569 / J. Brotton in Cartographic journal (the), vol 49 n° 2 (May 2012)
PermalinkEstimating geoid height change in North America: past, present and future / T. Jacob in Journal of geodesy, vol 86 n° 5 (May 2012)
PermalinkHydrological deformation induced by the West African Monsoon : Comparison of GPS, GRACE and loading models / Samuel Nahmani in Journal of geophysical research : Solid Earth, Vol 117 n° B5 (May 2012)
PermalinkImpact of Earth radiation pressure on GPS position estimates / C. Rodriguez-Solano in Journal of geodesy, vol 86 n° 5 (May 2012)
PermalinkPermalinkSimulation study of a follow-on gravity mission to GRACE / B. Loomis in Journal of geodesy, vol 86 n° 5 (May 2012)
PermalinkUnique national geodetic network in Cameroon / C. Michel in GIM international, vol 26 n° 5 (May 2012)
PermalinkIonospheric scintillations: How irregularities in electron density perturb satellite navigation systems / Satellite-based augmentation system ionospheric working group in GPS world, vol 23 n° 4 (April 2012)
PermalinkMitigation of atmospheric perturbations and solid Earth movements in a TerraSAR-X time-series / D. Small in Journal of geodesy, vol 86 n° 4 (April 2012)
PermalinkPersonal privacy jammers: Locating Jersey PPDs jamming GBAS [Ground-Based Augmentation System] safety-of-life signals / J. Grabowski in GPS world, vol 23 n° 4 (April 2012)
PermalinkUtilisation du GPS pour l'étude du séisme de Tohoku-Oki (11 mars 2011) [diaporama] / Lucie Rolland (08/03/2012)
PermalinkCoordonnées géographiques lambda, phi, h sur l'ellipsoïde de révolution / Patrick Julien in XYZ, n° 130 (mars - mai 2012)
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PermalinkGalileo's surveying potential: E5 pseudorange precision / Ismael Colomina in GPS world, vol 23 n° 3 (March 2012)
PermalinkGPS snow depth meter with geometry-free linear combinations of carrier phases / M. Ozeki in Journal of geodesy, vol 86 n° 3 (March 2012)
PermalinkThe sky is on the move: the benefits of Galileo / D. Jurry De La Mar in Geoinformatics, vol 15 n° 2 (01/03/2012)
PermalinkThe US Gravimetric Geoid of 2009 (USGG2009): model development and evaluation / Y. Wang in Journal of geodesy, vol 86 n° 3 (March 2012)
PermalinkFast integer least-squares estimation for GNSS high-dimensional ambiguity resolution using lattice theory / S. Jazaeri in Journal of geodesy, vol 86 n° 2 (February 2012)
PermalinkRay-traced slant factors for mitigating the tropospheric delay at the observation level / L. Urquhart in Journal of geodesy, vol 86 n° 2 (February 2012)
PermalinkRelative gravity measurement campaign during the 8th international comparison of absolute gravimeters (2009) / Z. Jiang in Metrologia, vol 49 n° 1 (February 2012)
PermalinkStudy of seasonal-scale atmospheric water cycle with ground-based GPS receivers, radiosondes and NWP models over Morocco / Achraf Koulali in Atmospheric Research, vol 104 - 105 (February 2012)
PermalinkThe unusual projection for one of John Dee’s maps of 1580 / D. Bower in Cartographic journal (the), vol 49 n° 1 (February 2012)
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