Descripteur
Termes IGN > sciences naturelles > sciences de la Terre et de l'univers > géosciences > géophysique interne > géodésie > géodésie spatiale > système de positionnement par satellites
système de positionnement par satellitesSynonyme(s)Sps |
Documents disponibles dans cette catégorie (940)
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
A multi-layer perceptron neural network to mitigate the interference of time synchronization attacks in stationary GPS receivers / N. Orouji in GPS solutions, vol 25 n° 3 (July 2021)
[article]
Titre : A multi-layer perceptron neural network to mitigate the interference of time synchronization attacks in stationary GPS receivers Type de document : Article/Communication Auteurs : N. Orouji, Auteur ; M. R. Mosavi, Auteur Année de publication : 2021 Article en page(s) : Article 84 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] décalage d'horloge
[Termes IGN] horloge du récepteur
[Termes IGN] méthode robuste
[Termes IGN] Perceptron multicouche
[Termes IGN] précision des données
[Termes IGN] récepteur GPS
[Termes IGN] station GPS
[Termes IGN] synchronisationRésumé : (Auteur) Accurate timing is one of the key features of the Global Positioning System (GPS), which is employed in many critical infrastructures. Any imprecise time measurement in GPS-based structures, such as smart power grids, economic activities, and communication towers, can lead to disastrous results. The vulnerability of the stationary GPS receivers to the time synchronization attacks (TSAs) jeopardizes the GPS timing precision and trust level. In the past few years, studies suggested the adoption of estimators to follow the authentic trend of the clock offset information under attack conditions. However, the estimators would lose track of the authentic signal without proper knowledge of the signal characteristics. Therefore, a multi-layer perceptron neural network (MLP NN) is proposed to follow the trend of the data. The main difference between the proposed method and typical estimators is the reliance of the network on the training information consisting of signal features. The proposed MLP NN performance has been evaluated through two real-world datasets and two well-known types of TSA. The root mean square error results exhibit an improvement of at least six times compared to other conventional and state-of-art methods. Numéro de notice : A2021-331 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-021-01124-z Date de publication en ligne : 05/04/2021 En ligne : https://doi.org/10.1007/s10291-021-01124-z Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97501
in GPS solutions > vol 25 n° 3 (July 2021) . - Article 84[article]Refining MODIS NIR atmospheric water vapor retrieval algorithm using GPS-derived water vapor data / Jia He in IEEE Transactions on geoscience and remote sensing, vol 59 n° 5 (May 2021)
[article]
Titre : Refining MODIS NIR atmospheric water vapor retrieval algorithm using GPS-derived water vapor data Type de document : Article/Communication Auteurs : Jia He, Auteur ; Zhizhao Liu, Auteur Année de publication : 2021 Article en page(s) : pp 3682 - 3694 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] Amérique du nord
[Termes IGN] données météorologiques
[Termes IGN] données spatiotemporelles
[Termes IGN] image Terra-MODIS
[Termes IGN] modèle de régression
[Termes IGN] modèle de transfert radiatif
[Termes IGN] précision des données
[Termes IGN] station GPS
[Termes IGN] vapeur d'eauRésumé : (Auteur) A new algorithm of retrieving atmospheric water vapor from MODIS near-infrared (IR) (NIR) data by using a regression fitting method based on Global Positioning System (GPS)-derived water vapor is developed in this work. The algorithm has been used to retrieve total column water vapor from Moderate Resolution Imaging Spectroradiometer (MODIS) satellites both Terra and Aqua under cloud-free conditions from solar radiation in the NIR channels. Water vapor data estimated from GPS observations recorded from 2003 to 2017 by the SuomiNet GPS network over the western North America are used as ground truth references. The GPS stations were classified into six subsets based on the surface types adopted from MCD12Q1 IGBP legend. The differences in surface types are considered in the regression fitting procedure, thus different regression functions are trained for different surface types. Thus, the wet bias in the operational MODIS water vapor products has been significantly reduced. Water vapor retrieved from each of the three absorption channels and the weighted water vapor of combined three absorption channels are analyzed. Validation shows that the weighted water vapor performs better than the single-channel results. Compared to the MODIS/Terra water vapor products, the RMSE has been reduced by 50.78% to 2.229 mm using the two-channel ratio transmittance method and has been reduced by 53.06% to 2.126 mm using the three-channel ratio transmittance method. Compared to the MODIS/Aqua water vapor products, the RMSE has been reduced by 45.54% to 2.423 mm using the two-channel ratio transmittance method and has been reduced by 45.34% to 2.432 mm using the three-channel ratio transmittance method. Numéro de notice : A2021-338 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2020.3016655 Date de publication en ligne : 24/08/2020 En ligne : https://doi.org/10.1109/TGRS.2020.3016655 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97569
in IEEE Transactions on geoscience and remote sensing > vol 59 n° 5 (May 2021) . - pp 3682 - 3694[article]Determination of precise Galileo orbits using combined GNSS and SLR observations / Grzegorz Bury in GPS solutions, vol 25 n° 1 (January 2021)
[article]
Titre : Determination of precise Galileo orbits using combined GNSS and SLR observations Type de document : Article/Communication Auteurs : Grzegorz Bury, Auteur ; Krzysztof Sosnica, Auteur ; Radoslaw Zajdel, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 11 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales
[Termes IGN] données GNSS
[Termes IGN] données TLS (télémétrie)
[Termes IGN] Galileo
[Termes IGN] International Terrestrial Reference Frame
[Termes IGN] orbite précise
[Termes IGN] orbitographie
[Termes IGN] pondérationRésumé : (auteur) Galileo satellites are equipped with laser retroreflector arrays for satellite laser ranging (SLR). In this study, we develop a methodology for the GNSS-SLR combination at the normal equation level with three different weighting strategies and evaluate the impact of laser observations on the determined Galileo orbits. We provide the optimum weighting scheme for precise orbit determination employing the co-location onboard Galileo. The combined GNSS-SLR solution diminishes the semimajor axis formal error by up to 62%, as well as reduces the dependency between values of formal errors and the elevation of the Sun above the orbital plane—the β angle. In the combined solution, the standard deviation of the SLR residuals decreases from 36.1 to 29.6 mm for Galileo-IOV satellites and |β|> 60°, when compared to GNSS-only solutions. Moreover, the bias of the Length-of-Day parameter is 20% lower for the combined solution when compared to the microwave one. As a result, the combination of GNSS and SLR observations provides promising results for future co-locations onboard the Galileo satellites for the orbit determination, realization of the terrestrial reference frames, and deriving geodetic parameters. Numéro de notice : A2021-008 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-020-01045-3 Date de publication en ligne : 31/10/2020 En ligne : https://doi.org/10.1007/s10291-020-01045-3 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96298
in GPS solutions > vol 25 n° 1 (January 2021) . - n° 11[article]
Titre : Galileo High Accuracy Service (HAS) Type de document : Ouvrage divers Auteurs : European GNSS Agency (GSA), Auteur Editeur : Prague [République tchèque] : European GNSS Agency (GSA) Année de publication : 2021 Importance : 16 p. Format : 21 x 30 cm Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] Galileo
[Termes IGN] positionnement par Galileo
[Termes IGN] positionnement ponctuel précis
[Termes IGN] précision du positionnementRésumé : (auteur) With the Galileo High Accuracy Service (HAS), Galileo will pioneer a worldwide, free high-accuracy positioning service aimed at applications that require higher performance than that offered by the Open Service. The HAS will be based on the provision of PPP corrections (orbit, clock, biases, atmospheric corrections), at a maximum rate of 448 bps per Galileo satellite connected to an uplink station, allowing the user to obtain a horizontal positioning error of less than two decimetres (95 %) in nominal conditions of use. The parameters and the business model of the service will foster innovation in both consolidated and emerging markets, notably in key areas such as drones and autonomous cars, minimising disruption in the current business models of established providers. The HAS will be implemented in three phases, including testing and experimentation; an initial Galileo High Accuracy Service for a reduced number of signals, with relaxed performance targets and a reduced coverage area; and a full Galileo HAS that will offer two service levels and global coverage. Service Level 1 will provide PPP corrections globally to achieve 20 cm horizontal precision with Note de contenu : 1- Introduction
2- Target markets
3- HAS service characterisation
4- HAS high level architecture
5- HAS roadmap
6- HAS relevant documentation and interfaces avialable
7- SummaryNuméro de notice : 28526 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Plaquette / brochure DOI : sans En ligne : https://www.gsa.europa.eu/newsroom/news/gsa-publishes-high-accuracy-service-info [...] Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97339
Titre : IDS Activity Report 2019-2020 Type de document : Rapport Auteurs : Laurent Soudarin, Auteur ; Pascale Ferrage, Auteur Editeur : Toulouse : International Doris Service, IDS Année de publication : 2021 Collection : IDS activity report Importance : 137 p. Format : 21 x 30 cm Note générale : Arnaud Pollet and Samuel Nahmani will lead the IGN/DORIS Analysis Center activities following the retirement of Pascal Willis. Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes de référence et réseaux
[Termes IGN] DORISNuméro de notice : 14389 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Rapport d'activité nature-HAL : Rapport DOI : sans En ligne : https://ids-doris.org/documents/report/IDS_Report_2019-2020.pdf Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101414 PermalinkPermalinkPermalinkPermalinkRapport d'activité 2020 de l'Institut National de l'Information Géographique et Forestière IGN, 1. Activité / Institut national de l'information géographique et forestière (2012 -) (2021)PermalinkRemote sensing and GIS / Basudeb Bhatta (2021)PermalinkReference system origin and scale realization within the future GNSS constellation “Kepler” / Susanne Glaser in Journal of geodesy, vol 94 n° 12 (December 2020)PermalinkLes stations virtuelles au service de la cartographie mobile / Mathieu Regul in XYZ, n° 165 (décembre 2020)PermalinkIntegrated processing of ground- and space-based GPS observations: improving GPS satellite orbits observed with sparse ground networks / Wen Huang in Journal of geodesy, vol 94 n° 10 (October 2020)PermalinkEvaluation of single-frequency receivers for studying crustal deformation at the longitudinal Valley fault, eastern Taiwan / Horng-Yue Chen in Survey review, vol 52 n° 374 (August 2020)Permalink