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Local GNSS monitoring / A. Guilloton in Navigation aérienne, maritime, spatiale, terrestre, vol 62 n° 247 (mai 2015)
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Titre : Local GNSS monitoring Type de document : Article/Communication Auteurs : A. Guilloton, Auteur ; B. Montagne, Auteur Année de publication : 2015 Article en page(s) : pp 26 - 35 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] Global Navigation Satellite System
[Termes IGN] interférence
[Termes IGN] qualité du signal
[Termes IGN] signal GNSSRésumé : (Auteur) [Introduction] Nowadays, GPS are used in many applications such as GBAS, SBAS, EGNOS and WAAS aircraft landing systems, unmanned road or aerial vehicles, wireline and wireless telecommunications networks, financial trading, electricity generation and supply, telematics insurance, tracking of assets, fleet vehicles and people, road user charging, geofenced applications... etc. GPS applications are vulnerable to jamming and spoofing, the former being intentional or not. [...] Numéro de notice : A2015-458 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77151
in Navigation aérienne, maritime, spatiale, terrestre > vol 62 n° 247 (mai 2015) . - pp 26 - 35[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 094-2015021 RAB Revue Centre de documentation En réserve L003 Disponible Vegetation sensing using GPS-interferometric reflectometry: theoretical effects of canopy parameters on signal-to-noise ratio data / C.C. Chew in IEEE Transactions on geoscience and remote sensing, vol 53 n° 5 (mai 2015)
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Titre : Vegetation sensing using GPS-interferometric reflectometry: theoretical effects of canopy parameters on signal-to-noise ratio data Type de document : Article/Communication Auteurs : C.C. Chew, Auteur ; E.E. Small, Auteur ; K. Larson, Auteur ; V. Zavorotny, Auteur Année de publication : 2015 Article en page(s) : pp 2755 - 2764 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] couvert végétal
[Termes IGN] humidité du sol
[Termes IGN] rapport signal sur bruit
[Termes IGN] réflectométrie par GNSS
[Termes IGN] signal GPS
[Termes IGN] végétationRésumé : (Auteur) The potential to use GPS signal-to-noise ratio (SNR) data to estimate changes in vegetation surrounding a ground-based antenna is evaluated. A 1-D plane-stratified model that simulates the response of GPS SNR data to changes in both soil moisture and vegetation is presented. The model is validated against observations of SNR data from four field sites with varying vegetation cover. Validation shows that the average correlation between modeled and observed SNR data is higher than the average correlation between concurrent SNR observations from different satellite tracks at a site. The model also reproduces variations in the SNR metrics amplitude, phase, and effective reflector height over a range of vegetation wet weights from 0 to 4 kg · m-2, with r2 values of 0.79, 0.84, and 0.62, respectively. Model simulations indicate that the amplitude of SNR oscillations may be used to estimate vegetation amount when vegetation wet weight is below 1.5 kg · m-2. When vegetation wet weight exceeds 1.5 kg · m-2, the sensitivity of amplitude to changes in vegetation amount decreases. Phase of SNR oscillations also varies consistently with vegetation up to 1.5 kg · m-2. However, phase is also very sensitive to soil moisture variations, thus limiting its utility for estimating vegetation. Effective reflector height is not a consistent indicator of vegetation change. Beyond 1.5 kg · m-2, the constant frequency assumption used to characterize SNR fluctuations does not adequately describe observed data. A more complex approach than the standard SNR metrics used here is required to extend GPS-Interferometric Reflectometry sensing to thicker canopies. Numéro de notice : A2015-517 Affiliation des auteurs : non IGN Thématique : FORET/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2014.2364513 En ligne : https://doi.org/10.1109/TGRS.2014.2364513 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77523
in IEEE Transactions on geoscience and remote sensing > vol 53 n° 5 (mai 2015) . - pp 2755 - 2764[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 065-2015051 RAB Revue Centre de documentation En réserve L003 Disponible Carrier-phase ambiguity resolution: Handling the biases for improved triple-frequency PPP convergence / Denis Laurichesse in GPS world, vol 26 n° 4 (April 2015)
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Titre : Carrier-phase ambiguity resolution: Handling the biases for improved triple-frequency PPP convergence Type de document : Article/Communication Auteurs : Denis Laurichesse, Auteur Année de publication : 2015 Article en page(s) : pp 42 - 49 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] convergence
[Termes IGN] erreur systématique
[Termes IGN] onde porteuse
[Termes IGN] phase
[Termes IGN] phase GPS
[Termes IGN] positionnement différentiel
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur trifréquence
[Termes IGN] résolution d'ambiguïtéRésumé : (éditeur) [...] The other precision of PPP is its use of carrier-phase measurements rather than just pseudoranges. Carrier-phase measurements have a precision on the order of two magnitudes (a factor of 100) better than that of pseudoranges. But there is a catch to the use of carrier-phase measurements: they are ambiguous by an integer multiple of one cycle. Processing algorithms must resolve the value of this ambiguity and ideally fix it at its correct integer value. Unfortunately, it is difficult to do this instantaneously, and often many epochs of measurements are needed for a position solution to converge to a sufficiently high accuracy, say better than 10 centimeters. Researchers are actively working on reducing the convergence time, and this month'column, we look at how using measurements from three satellite frequencies rather than just two can help. Numéro de notice : A2015-092 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : http://gpsworld.com/innovation-carrier-phase-ambiguity-resolution/ Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75588
in GPS world > vol 26 n° 4 (April 2015) . - pp 42 - 49[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 067-2015041 RAB Revue Centre de documentation En réserve L003 Disponible Galileo E1 and E5a Performance for multi-frequency, multi-constellation GBAS / Mihaela-Simona Circiu in GPS world, vol 26 n° 4 (April 2015)
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Titre : Galileo E1 and E5a Performance for multi-frequency, multi-constellation GBAS Type de document : Article/Communication Auteurs : Mihaela-Simona Circiu, Auteur ; Michael Felux, Auteur ; Sam Pullen, Auteur Année de publication : 2015 Article en page(s) : pp 30 - 35 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] antenne Galileo
[Termes IGN] antenne GPS
[Termes IGN] performance
[Termes IGN] rapport signal sur bruit
[Termes IGN] signal Galileo
[Termes IGN] signal GPS
[Termes IGN] station permanente
[Termes IGN] système d'extension
[Termes IGN] traitement du signal
[Termes IGN] trajet multipleRésumé : (auteur) Analysis of new Galileo signals at an experimental ground-based augmentation system (GBAS) compares noise and multipath in their performance to GPS L1 and L5. Raw noise and multipath level of the Galileo signals is shown to be smaller than those of GPS. Even after smoothing, Galileo signals perform somewhat better than GPS and are less sensitive to the smoothing time constant. Numéro de notice : A2015-091 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : http://gpsworld.com/galileo-e1-and-e5a-performance-for-multi-frequency-multi-con [...] Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75587
in GPS world > vol 26 n° 4 (April 2015) . - pp 30 - 35[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 067-2015041 RAB Revue Centre de documentation En réserve L003 Disponible SHPTS: towards a new method for generating precise global ionospheric TEC map based on spherical harmonic and generalized trigonometric series functions / Zishen Li in Journal of geodesy, vol 89 n° 4 (April 2015)
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Titre : SHPTS: towards a new method for generating precise global ionospheric TEC map based on spherical harmonic and generalized trigonometric series functions Type de document : Article/Communication Auteurs : Zishen Li, Auteur ; Yunbin Yuan, Auteur ; Ningbo Wang, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 333 - 345 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] données DORIS
[Termes IGN] données Topex-Poseidon
[Termes IGN] fonction harmonique
[Termes IGN] harmonique sphérique
[Termes IGN] modèle ionosphérique
[Termes IGN] série de Fourier
[Termes IGN] signal GNSS
[Termes IGN] teneur totale en électrons
[Termes IGN] trigonométrie sphériqueRésumé : (auteur) To take maximum advantage of the increasing Global Navigation Satellite Systems (GNSS) data to improve the accuracy and resolution of global ionospheric TEC map (GIM), an approach, named Spherical Harmonic plus generalized Trigonometric Series functions (SHPTS), is proposed by integrating the spherical harmonic and the generalized trigonometric series functions on global and local scales, respectively. The SHPTS-based GIM from January 1st, 2001 to December 31st, 2011 (about one solar cycle) is validated by the ionospheric TEC from raw global GPS data, the GIM released by the current Ionospheric Associate Analysis Center (IAAC), the TOPEX/Poseidon satellite and the DORIS. The present results show that the SHPTS-based GIM over the area where no real data are available has the same accuracy level (approximately 2–6 TECu) to that released by the current IAAC. However, the ionospheric TEC in the SHPTS-based GIM over the area covered by real data is more accurate (approximately 1.5 TECu) than that of the GIM (approximately 3.0 TECu) released by the current IAAC. The external accuracy of the SHPTS-based GIM validated by the TOPEX/Poseidon and DORIS is approximately 2.5–5.5 and 1.5–4.5 TECu, respectively. In particular, the SHPTS-based GIM is the best or almost the best ranked, along with those of JPL and UPC, when they are compared with TOPEX/Poseidon measurements, and the best (in addition to UPC) when they are validated with DORIS data. With the increase in the number of GNSS satellites and contributing stations, the performance of the SHPTS-based GIM can be further improved. The SHPTS-based GIM routinely calculated using global GPS, GLONASS and BDS data will be found at the website http://www.gipp.org.cn. Numéro de notice : A2015-341 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0778-9 Date de publication en ligne : 02/12/2014 En ligne : https://doi.org/10.1007/s00190-014-0778-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76710
in Journal of geodesy > vol 89 n° 4 (April 2015) . - pp 333 - 345[article]Three-Corner Hat for the assessment of the uncertainty of non-linear residuals of space-geodetic time series in the context of terrestrial reference frame analysis / Claudio Abbondanza in Journal of geodesy, vol 89 n° 4 (April 2015)PermalinkEstimating ionospheric delay using GPS/Galileo signals in the E5 band / Olivier Julien in Inside GNSS, vol 10 n° 2 (March - April 2015)PermalinkGNSS-R : Signaux réfléchis / Marielle Mayo in Géomètre, n° 2123 (mars 2015)PermalinkLevelling co-located GNSS and tide gauge stations using GNSS reflectometry / Alvaro Santamaria Gomez in Journal of geodesy, vol 89 n° 3 (March 2015)PermalinkExtending the reach of SBAS : Some aspects of EGNOS performance in Ukraine / Valeriy Konin in Inside GNSS, vol 10 n° 1 (January - February 2015)PermalinkFrom Data Schemes to Supersonic Codes : GNSS Authentication for Modernized Signals / Oscar Pozzobon in Inside GNSS, vol 10 n° 1 (January - February 2015)PermalinkAccounting for Galileo–GPS inter-system biases in precise satellite positioning / Jacek Paziewski in Journal of geodesy, vol 89 n° 1 (January 2015)PermalinkFirst Galileo FOC satellite on the air: Will be employable for surveying, precise positionning, and geodesy / Peter Steingenberger in GPS world, vol 26 n° 1 (January 2015)PermalinkGPS for land surveyors / Jan Van Sickle (2015)PermalinkPermalink