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Assessing and mitigating the effects of the ionospheric variability on DGPS / Duojie Weng in GPS solutions, vol 19 n° 1 (January 2015)
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Titre : Assessing and mitigating the effects of the ionospheric variability on DGPS Type de document : Article/Communication Auteurs : Duojie Weng, Auteur ; Shengyue Ji, Auteur ; Wu Chen, Auteur ; Zhihua Li, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 107 - 116 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] GPS en mode différentiel
[Termes IGN] gradient ionosphèrique
[Termes IGN] ionosphère
[Termes IGN] modèle ionosphérique
[Termes IGN] retard ionosphèrique
[Termes IGN] traitement de données GNSSRésumé : (auteur) The differential GPS (DGPS) performance can be affected by the ionospheric variability, especially in low-latitude areas. We evaluated the behavior of the ionospheric variability in low-latitude areas in the 11-year cycle of the solar activity. During periods of solar maximum, the percentage of the daily maximum gradient that exceeds 50 mm/km has reached 73 % in 2001. Assuming that the baseline length is 20 km, the gradient larger than 50 mm/km can lead to more than 1.0-m ranging error, which is significant if we want to achieve meter-level accuracy with DGPS. An ionospheric gradient model built from a number of reference stations is proposed for estimating the differential ionospheric delays. The effectiveness of the model is demonstrated under both the quiet and active ionospheric conditions in low-latitude areas. For a short baseline length of 16.9 km in Hong Kong, the horizontal positioning accuracy can be improved by 41 and 61 % during active solar years and geomagnetic storms, respectively. The improvements show that the model is capable of reducing the spatial decorrelation caused by the ionospheric variability, and the model can be used in DGPS especially over the regions, such as low-latitude areas, where the large ionospheric variability happens frequently. Numéro de notice : A2015-201 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-014-0372-x Date de publication en ligne : 13/04/2014 En ligne : https://doi.org/10.1007/s10291-014-0372-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76019
in GPS solutions > vol 19 n° 1 (January 2015) . - pp 107 - 116[article]Extending the reach of SBAS : Some aspects of EGNOS performance in Ukraine / Valeriy Konin in Inside GNSS, vol 10 n° 1 (January - February 2015)
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Titre : Extending the reach of SBAS : Some aspects of EGNOS performance in Ukraine Type de document : Article/Communication Auteurs : Valeriy Konin, Auteur ; Fedir Shyshkov, Auteur Année de publication : 2015 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] European Geostationary Navigation Overlay Service
[Termes IGN] fiabilité des données
[Termes IGN] signal GNSS
[Termes IGN] système d'extension
[Termes IGN] UkraineRésumé : (auteur) Although the European Geostationary Navigation Overlay Service is primarily designed to provide benefits from a space-based augmentation system that serves the European Union nations, it actually covers regions outside that geographic area. In this article, researchers tracking EGNOS signal availability in Ukraine conclude that its performance there is improving in robustness and reliability. Numéro de notice : A2015-255 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : http://www.insidegnss.com/node/4366 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76295
in Inside GNSS > vol 10 n° 1 (January - February 2015)[article]From Data Schemes to Supersonic Codes : GNSS Authentication for Modernized Signals / Oscar Pozzobon in Inside GNSS, vol 10 n° 1 (January - February 2015)
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Titre : From Data Schemes to Supersonic Codes : GNSS Authentication for Modernized Signals Type de document : Article/Communication Auteurs : Oscar Pozzobon, Auteur ; Giovanni Gamba, Auteur ; Matteo Canale, Auteur ; et al., Auteur Année de publication : 2015 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] authentification
[Termes IGN] leurrage
[Termes IGN] signal GNSSRésumé : (auteur) The problem of GNSS signal authentication is expected to draw ever more attention in an operational environment that poses a growing risk — and consequences — for “spoofing” attacks. A team of researchers present an overview of the requirements and methods for verifying the authenticity of the signals and introduce a novel scheme for authentication of open GNSS signals using supersonic codes. Numéro de notice : A2015-256 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : http://www.insidegnss.com/node/4370 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76290
in Inside GNSS > vol 10 n° 1 (January - February 2015)[article]Galileo orbit determination using combined GNSS and SLR observations / Stefan Hackel in GPS solutions, vol 19 n° 1 (January 2015)
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Titre : Galileo orbit determination using combined GNSS and SLR observations Type de document : Article/Communication Auteurs : Stefan Hackel, Auteur ; Peter Steigenberger, Auteur ; Urs Hugentobler, Auteur Année de publication : 2015 Article en page(s) : pp 15 - 25 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales
[Termes IGN] données TLS (télémétrie)
[Termes IGN] erreur systématique
[Termes IGN] GIOVE (satellite)
[Termes IGN] indicateur de qualité
[Termes IGN] modèle linéaire
[Termes IGN] orbite
[Termes IGN] orbitographie
[Termes IGN] positionnement par GNSS
[Termes IGN] qualité des donnéesRésumé : (auteur) The first two Galileo In-Orbit Validation satellites were launched in October 2011 and started continuous signal transmission on all frequencies in early 2012. Both satellites are equipped with two different types of clocks, namely rubidium clocks and hydrogen masers. Based on two test periods, the quality of the Galileo orbit determination based on Global Navigation Satellite System (GNSS) and Satellite Laser Ranging (SLR) observations is assessed. The estimated satellite clock parameters are used as quality indicator for the orbits: A bump at orbital periods in the Allan deviation indicates systematic errors in the GNSS-only orbit determination. These errors almost vanish if SLR observations are considered in addition. As the internal consistency is degraded by the combination, the offset of the SLR reflector is shifted by +5 cm, resulting in an improved orbit consistency as well as accuracy. Another approach to reduce the systematic errors of the GNSS-only orbit determination employs constraints for the clock estimates with respect to a linear model. In general, one decimeter orbit accuracy could be achieved. Numéro de notice : A2015-202 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-013-0361-5 Date de publication en ligne : 09/01/2014 En ligne : https://doi.org/10.1007/s10291-013-0361-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76015
in GPS solutions > vol 19 n° 1 (January 2015) . - pp 15 - 25[article]Accounting for Galileo–GPS inter-system biases in precise satellite positioning / Jacek Paziewski in Journal of geodesy, vol 89 n° 1 (January 2015)
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Titre : Accounting for Galileo–GPS inter-system biases in precise satellite positioning Type de document : Article/Communication Auteurs : Jacek Paziewski, Auteur ; Pawel Wielgosz, Auteur Année de publication : 2015 Article en page(s) : pp 81 - 93 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] acquisition de données
[Termes IGN] analyse comparative
[Termes IGN] données GNSS
[Termes IGN] double différence
[Termes IGN] erreur systématique
[Termes IGN] fusion de données
[Termes IGN] positionnement différentiel
[Termes IGN] signal Galileo
[Termes IGN] signal GPS
[Termes IGN] stabilité dans le tempsRésumé : (auteur) Availability of two overlapping frequencies L1/E1 and L5/E5a of the signals transmitted by GPS and Galileo systems offers the possibility of tightly combining observations from both systems in a single observational model. A tightly combined observational model assumes a single reference satellite for all observations from both Galileo and GPS systems. However, when inter-system double-differenced observations are created, receiver inter-system bias is introduced. This study presents the results and the methodology for estimation and accounting for phase and code GPS-Galileo inter-system bias in precise relative positioning. The research investigates the size and temporal stability of the estimated bias for different receiver pairs as well as examines the influence of accounting for the inter-system bias on the user position solution. The obtained numerical results are based on four experiments carried out at different locations and time periods using both real and simulated GNSS data. Numéro de notice : A2015-329 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-014-0763-3 En ligne : https://doi.org/10.1007/s00190-014-0763-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76654
in Journal of geodesy > vol 89 n° 1 (January 2015) . - pp 81 - 93[article]Determination of precise satellite orbits and geodetic parameters using satellite laser ranging / Krzysztof Sosnica (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)
PermalinkPermalinkGéodésie multi-technique pour la surveillance haute fréquence de glissements de terrains / Pierre Boetzle (2015)
PermalinkGOCE: assessment of GPS-only gravity field determination / Adrian Jäggi in Journal of geodesy, vol 89 n° 1 (January 2015)
PermalinkPermalinkPermalinkPermalinkHierarchical extraction of urban objects from mobile laser scanning data / Bisheng Yang in ISPRS Journal of photogrammetry and remote sensing, vol 99 (January 2015)
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