Descripteur
Documents disponibles dans cette catégorie (54)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
The ionosphere : effects, GPS modeling and the benefits for space geodetic techniques / Manuel Hernández-Pajares in Journal of geodesy, vol 85 n° 12 (December 2011)
[article]
Titre : The ionosphere : effects, GPS modeling and the benefits for space geodetic techniques Type de document : Article/Communication Auteurs : Manuel Hernández-Pajares, Auteur ; M. Juan, Auteur ; Jaume Sanz, Auteur ; et al., Auteur Année de publication : 2011 Article en page(s) : pp 887 - 907 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] données GNSS
[Termes IGN] données GPS
[Termes IGN] ionosphère
[Termes IGN] modèle ionosphérique
[Termes IGN] perturbation ionosphérique
[Termes IGN] propagation du signal
[Termes IGN] qualité du signal
[Termes IGN] signal GNSS
[Termes IGN] signal GPS
[Termes IGN] surveillance
[Termes IGN] teneur totale en électronsRésumé : (Auteur) The main goal of this paper is to provide a summary of our current knowledge of the ionosphere as it relates to space geodetic techniques, especially the most informative technology, global navigation satellite systems (GNSS), specifically the fully deployed and operational global positioning system (GPS). As such, the main relevant modeling points are discussed, and the corresponding results of ionospheric monitoring are related, which were mostly computed using GPS data and based on the direct experience of the authors. We address various phenomena such as horizontal and vertical ionospheric morphology in quiet conditions, traveling ionospheric disturbances, solar flares, ionospheric storms and scintillation. Finally, we also tackle the question of how improved knowledge of ionospheric conditions, especially in terms of an accurate understanding of the distribution of free electrons, can improve space geodetic techniques at different levels, such as higher-order ionospheric effects, precise GNSS navigation, single-antenna GNSS orientation and real-time GNSS meteorology. Numéro de notice : A2011-501 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0508-5 Date de publication en ligne : 11/09/2011 En ligne : https://doi.org/10.1007/s00190-011-0508-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31395
in Journal of geodesy > vol 85 n° 12 (December 2011) . - pp 887 - 907[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2011121 RAB Revue Centre de documentation En réserve L003 Disponible Interpolating atmospheric water vapor delay by incorporating terrain elevation information / B. Xu in Journal of geodesy, vol 85 n° 9 (September 2011)
[article]
Titre : Interpolating atmospheric water vapor delay by incorporating terrain elevation information Type de document : Article/Communication Auteurs : B. Xu, Auteur ; Z.W. Li, Auteur ; Jianjun Zhu, Auteur Année de publication : 2011 Article en page(s) : pp 555 - 564 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] dégradation du signal
[Termes IGN] écho radar
[Termes IGN] interféromètrie par radar à antenne synthétique
[Termes IGN] interpolation spatiale
[Termes IGN] modèle numérique de surface
[Termes IGN] propagation du signal
[Termes IGN] signal GPS
[Termes IGN] vapeur d'eauRésumé : (Auteur) In radio signal-based observing systems, such as Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR), the water vapor in the atmosphere will cause delays during the signal transmission. Such delays vary significantly with terrain elevation. In the case when atmospheric delays are to be eliminated from the measured raw signals, spatial interpolators may be needed. By taking advantage of available terrain elevation information during spatial interpolation process, the accuracy of the atmospheric delay mapping can be considerably improved. This paper first reviews three elevation-dependent water vapor interpolation models, i.e., the Best Linear Unbiased Estimator in combination with the water vapor Height Scaling Model (BLUE + HSM), the Best Linear Unbiased Estimator coupled with the Elevation-dependent Covariance Model (BLUE + ECM), and the Simple Kriging with varying local means based on the Baby semi-empirical model (SKlm + Baby for short). A revision to the SKlm + Baby model is then presented, where the Onn water vapor delay model is adopted to substitute the inaccurate Baby semi-empirical model (SKlm + Onn for short). Experiments with the zenith wet delays obtained through the GPS observations from the Southern California Integrated GPS Network (SCIGN) demonstrate that the SKlm + Onn model outperforms the other three. The RMS of SKlm + Onn is only 0.55 cm, while those of BLUE + HSM, BLUE + ECM and SKlm + Baby amount to 1.11, 1.49 and 0.77 cm, respectively. The proposed SKlm + Onn model therefore represents an improvement of 29–63% over the other known models. Numéro de notice : A2011-374 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0456-0 Date de publication en ligne : 08/03/2011 En ligne : https://doi.org/10.1007/s00190-011-0456-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31153
in Journal of geodesy > vol 85 n° 9 (September 2011) . - pp 555 - 564[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2011091 RAB Revue Centre de documentation En réserve L003 Disponible VLBI-derived troposphere parameters during CONT08 / Robert Heinkelmann in Journal of geodesy, vol 85 n° 7 (July 2011)
[article]
Titre : VLBI-derived troposphere parameters during CONT08 Type de document : Article/Communication Auteurs : Robert Heinkelmann, Auteur ; Johannes Böhm , Auteur ; S. Bolotin, Auteur ; et al., Auteur Année de publication : 2011 Article en page(s) : pp 377 - 393 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] données ITGB
[Termes IGN] positionnement par ITGB
[Termes IGN] propagation du signal
[Termes IGN] propagation troposphérique
[Termes IGN] traitement de donnéesRésumé : (Auteur) Time-series of zenith wet and total troposphere delays as well as north and east gradients are compared, and zenith total delays (ZTD) are combined on the level of parameter estimates. Input data sets are provided by ten Analysis Centers (ACs) of the International VLBI Service for Geodesy and Astrometry (IVS) for the CONT08 campaign (12–26 August 2008). The inconsistent usage of meteorological data and models, such as mapping functions, causes systematics among the ACs, and differing parameterizations and constraints add noise to the troposphere parameter estimates. The empirical standard deviation of ZTD among the ACs with regard to an unweighted mean is 4.6 mm. The ratio of the analysis noise to the observation noise assessed by the operator/software impact (OSI) model is about 2.5. These and other effects have to be accounted for to improve the intra-technique combination of VLBI-derived troposphere parameters. While the largest systematics caused by inconsistent usage of meteorological data can be avoided and the application of different mapping functions can be considered by applying empirical corrections, the noise has to be modeled in the stochastic model of intra-technique combination. The application of different stochastic models shows no significant effects on the combined parameters but results in different mean formal errors: the mean formal errors of the combined ZTD are 2.3 mm (unweighted), 4.4 mm (diagonal), 8.6 mm [variance component (VC) estimation], and 8.6 mm (operator/software impact, OSI). On the one hand, the OSI model, i.e. the inclusion of off-diagonal elements in the cofactor-matrix, considers the reapplication of observations yielding a factor of about two for mean formal errors as compared to the diagonal approach. On the other hand, the combination based on VC estimation shows large differences among the VCs and exhibits a comparable scaling of formal errors. Thus, for the combination of troposphere parameters a combination of the two extensions of the stochastic model is recommended. Numéro de notice : A2011-330 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-011-0459-x Date de publication en ligne : 27/04/2011 En ligne : https://doi.org/10.1007/s00190-011-0459-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31109
in Journal of geodesy > vol 85 n° 7 (July 2011) . - pp 377 - 393[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2011071 RAB Revue Centre de documentation En réserve L003 Disponible Potentialities of multifrequency ionospheric correction in Global Navigation Satellite Systems / B. Kim in Journal of geodesy, vol 85 n° 3 (March 2011)
[article]
Titre : Potentialities of multifrequency ionospheric correction in Global Navigation Satellite Systems Type de document : Article/Communication Auteurs : B. Kim, Auteur ; M. Tinin, Auteur Année de publication : 2011 Article en page(s) : pp 159 - 169 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] correction ionosphérique
[Termes IGN] diffraction
[Termes IGN] propagation du signal
[Termes IGN] récepteur bifréquence
[Termes IGN] récepteur GNSS
[Termes IGN] résidu
[Termes IGN] traitement de données GNSS
[Termes IGN] varianceRésumé : (Auteur) The first-order ionospheric error is reduced in the dual-frequency Global Navigation Satellite Systems (GNSS). In this paper, the possibility of eliminating ionospheric higher-order errors in the multifrequency GNSS is explored. Since the second-order error associated with the geomagnetic field effect on the refractive index can be eliminated in dual-frequency measurements, we explore the possibility of eliminating third-order errors in triple-frequency GNSS in view of phase scintillations. A connection between the possibility of improving the multifrequency GNSS accuracy and diffraction effects in radio signal propagation through the randomly inhomogeneous ionosphere is shown. The numerical simulation has revealed that the systematic, residual ionospheric error is considerably reduced when we pass on from dual-frequency to triple-frequency measurements. The change in the residual error variance during such a transition depends however on the relationship between the inner scale of the turbulent spectrum of ionospheric irregularities and the Fresnel radius. Given the inner scale larger than the Fresnel radius, not only the systematic error, but also the standard deviation reduces when we pass on from dual-frequency to triple-frequency measurements. Otherwise, when the Fresnel radius exceeds the inner scale, the variance increases with increasing number of frequencies in use. Numéro de notice : A2011-165 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-010-0425-z Date de publication en ligne : 27/11/2010 En ligne : https://doi.org/10.1007/s00190-010-0425-z Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30943
in Journal of geodesy > vol 85 n° 3 (March 2011) . - pp 159 - 169[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 266-2011031 RAB Revue Centre de documentation En réserve L003 Disponible Physical limitations on detecting tunnels using underground-focusing spotlight synthetic aperture radar / J. Martinez-Lorenzo in IEEE Transactions on geoscience and remote sensing, vol 49 n° 1 Tome 1 (January 2011)
[article]
Titre : Physical limitations on detecting tunnels using underground-focusing spotlight synthetic aperture radar Type de document : Article/Communication Auteurs : J. Martinez-Lorenzo, Auteur ; C. Rappaport, Auteur ; F. Quivira, Auteur Année de publication : 2011 Conférence : IGARSS 2009, International Geoscience And Remote Sensing Symposium 12/07/2009 17/07/2009 Le Cap Afrique du sud Proceedings IEEE Article en page(s) : pp 65 - 70 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] constante diélectrique
[Termes IGN] détection de partie cachée
[Termes IGN] écho radar
[Termes IGN] forme d'onde
[Termes IGN] image radar moirée
[Termes IGN] propagation du signal
[Termes IGN] réflectance du sol
[Termes IGN] réfraction atmosphérique
[Termes IGN] rugosité du sol
[Termes IGN] sable
[Termes IGN] tunnelRésumé : (Auteur) This paper examines the feasibility of underground-focusing spotlight synthetic aperture radar (UF-SL-SAR) systems for tunnel detection applications. A general formulation is reviewed for generating UF-SL-SAR imaging by using multiple frequencies across a wide band and by focusing in space to subsurface points using well-known ray refraction at the nominal ground surface. A full-wave finite-difference frequency-domain model is used to consider wave propagation in realistic soil with loss- and frequency-dependent dielectric constant and a randomly rough ground surface, both of which serve to obscure and distort the returned tunnel target signal. Imaging results are presented for two representative soil scenarios: dry sand and moist clay loam. Considering the ground surface ray refraction for focusing greatly improves the SAR image relative to conventional SAR focusing at the ground surface. Using UF-SL-SAR, a small shallow tunnel is reasonably imaged for the sand case, despite the roughness of the ground interface. However, for higher conductivity moist clay loam, the clutter from the rough surface overwhelms the significantly attenuated target signal, which must propagate through the lossy intervening soil. It is demonstrated that, despite ideal focusing, the tunnel is successfully imaged only for the sand case. Numéro de notice : A2011-048 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2010.2051952 Date de publication en ligne : 19/08/2010 En ligne : https://doi.org/10.1109/TGRS.2010.2051952 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30829
in IEEE Transactions on geoscience and remote sensing > vol 49 n° 1 Tome 1 (January 2011) . - pp 65 - 70[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 065-2011011A RAB Revue Centre de documentation En réserve L003 Disponible A case study of using Raman lidar measurements in high-accuracy GPS applications / Pierre Bosser in Journal of geodesy, vol 84 n° 4 (April 2010)PermalinkTesting of Global Pressure-Temperature (GPT) Model and Global Mapping Function (GMF) in GPS analyses / Jan Kouba in Journal of geodesy, vol 83 n° 3-4 (March - April 2009)PermalinkDeploying a Locata network to enable precise positioning in urban canyons / J.P. Montillet in Journal of geodesy, vol 83 n° 2 (February 2009)PermalinkIonospheric modeling for precise GNSS applications / Y. Memarzadeh (2009)PermalinkPrediction and visualization of GPS multipath signals in urban areas using LiDAR Digital Surface Models and building footprints / J. Li in International journal of geographical information science IJGIS, vol 22 n°11-12 (november 2008)PermalinkSources d'erreurs et combinaisons linéaires des trois fréquences du système Galiléo pour le positionnement différentiel / L. Tabti in Bulletin des sciences géographiques, n° 22 (octobre 2008)PermalinkADOP in closed form for a hierarchy of multi-frequency single-baseline GNSS models / Dennis Odijk in Journal of geodesy, vol 82 n° 8 (August 2008)PermalinkDevelopment of a simulation model to predict Lidar interception in forested environments / N.R. Goodwin in Remote sensing of environment, vol 111 n° 4 (28/12/2007)PermalinkLe positionnement en intérieur / Nel Samama in XYZ, n° 112 (septembre - novembre 2007)PermalinkEtude pour la réalisation de cartes de visibilité satellitaire GNSS / G. Bizouard in XYZ, n° 111 (juin - août 2007)PermalinkTechnique de localisation intra-muros à transmission ultra large bande / V. Renaudin in XYZ, n° 111 (juin - août 2007)PermalinkContinuous navigation: combining GPS with sensor-based dead reckoning / G.Z. Bronsen in GPS world, vol 16 n° 4 (April 2005)PermalinkThe GNSS integer ambiguities / S. Verhagen (2005)PermalinkSatellite geodesy : foundations, methods and applications / Günter Seeber (2003)PermalinkErrors of signal processing in digital terrain modelling / Igor V. Florinsky in International journal of geographical information science IJGIS, vol 16 n° 5 (july 2002)PermalinkDevelopment of a dispersometer for the implementation into geodetic high-accuracy direction measurement systems / Burkhard Böckem (2001)PermalinkLasermessungen nach Erdsatelliten auf zwei Wellenlängen unter Verwendung einer Streak-Kamera / S. Riepl (1998)PermalinkEntwicklung eines Meßsystems zur Ermittlung von Turbulenzparametern der Atmosphäre für Anwendungen in der Geodäsie / Maria Hennes (1995)PermalinkSatellitengeodätische Positionierung in der relativistischen Raum-Zeit / V. Schwarze (1995)PermalinkMultipath and GPS / C. Bosloper (1990)Permalink