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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
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Code-barres Cote Support Localisation Section Disponibilité 266-2011121 RAB Revue Centre de documentation En réserve L003 Disponible GLONASS: developping strategies for the future / Y. Urlichich in GPS world, vol 22 n° 4 (April 2011)
[article]
Titre : GLONASS: developping strategies for the future Type de document : Article/Communication Auteurs : Y. Urlichich, Auteur ; V. Subbotin, Auteur ; et al., Auteur Année de publication : 2011 Article en page(s) : pp 42 - 49 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] code GLONASS
[Termes IGN] constellation GLONASS
[Termes IGN] qualité du signal
[Termes IGN] signal GLONASS
[Termes IGN] station GLONASS
[Termes IGN] système de positionnement par satellites
[Termes IGN] traitement du signalRésumé : (Auteur) It's no longer just a GPS world. Russia's GLONASS, or Global'naya Navigat-slonaya Sputnikova Sistema, will soon have a full complement of satellites in orbit providing positioning, navigation, and timing worldwide. The Soviet Union began development of GLONASS in 1976 just a few years after work started on GPS. The first satellite was launched in 1982 and a fully populated constellation of 24 functioning satellites was achieved in early 1996. However, due to economic difficulties following the dismantling of the Soviet Union, by 2002 the constellation had dropped to as few as seven satellites. But the Russian economy improved, and restoration of GLONASS was given high priority by the Russian government. The satellite constellation was gradually rejuvenated using primarily a new modernized spacecraft, GLONASS-M. The new design offered many improvements, including better onboard electronics, a longer lifetime, an L2 civil signal, and an improved navigation message. The GLONASS-M spacecraft still used a pressurized, hermetically sealed cylinder for the electronics, as had the earlier versions. Today, 26 functional GLONASS-M satellites are on orbit, 22 of them in service and providing usable signals, with four more having reserve status. A full constellation of 24 satellites should be available later this year with launches of several GLONASS-M satellites and the latest variant, the GLONASS-K Satellite. GLONASS-K satellites are markedly different from their predecessors. They are lighter, use an unpressurized housing (similar to that of GPS satellites), have improved clock stability, and a longer, 10-year design life. They also include, for the first time, code-division-multiple-access (CDMA) signals accompanying the legacy frequency-division-multiple-access signals. There will be two versions: GLONASS-K1 will transmit a CDMA signal on a new L3 frequency, and GLONASS-K2, in addition, will feature CDMA signals on L1 and L2 frequencies. The first GLONASS-K1 satellite was launched on February 26 and is now undergoing tests. GLONASS is being further improved with a satellite-based augmentation system. Called the System for Differential Correction and Monitoring or SDCM, it will use a ground network of monitoring stations and Luch geostationary communication satellites to transmit correction and integrity data using the GPS L1 frequency. The first of these satellites, Luch-5A, will be launched this year. In this month's column, a team of authors from Russian Space Systems, a key developer of navigation and geospatial technologies in the Russian aerospace industry, describes the new L3 CDMA signal to be broadcast by GLONASS-K satellites and the progress to date in developing the SDCM augmentation system. Numéro de notice : A2011-153 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30932
in GPS world > vol 22 n° 4 (April 2011) . - pp 42 - 49[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 067-2011041 RAB Revue Centre de documentation En réserve L003 Disponible GNSS and the Ionosphere: What's in Store for the Next Solar Maximum? / A. Jensen in GPS world, vol 22 n° 2 (February 2011)
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Titre : GNSS and the Ionosphere: What's in Store for the Next Solar Maximum? Type de document : Article/Communication Auteurs : A. Jensen, Auteur ; C. Mitchell, Auteur Année de publication : 2011 Article en page(s) : pp 40 - 48 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] dégradation du signal
[Termes IGN] ionosphère
[Termes IGN] perturbation ionosphérique
[Termes IGN] qualité du signal
[Termes IGN] signal aléatoire
[Termes IGN] signal GNSS
[Termes IGN] vent solaireRésumé : (Editeur) Although the sun can become disturbed at any time, solar activity is correlated with the approximately 11-year cycle of spots on the sun's surface. We are just coming out of a minimum in the solar cycle and headed for the next maximum, predicted to occur around the middle of 2013. How significantly will GNSS users be affected? In this month's column, two ionosphere experts tell us what might be in store. Numéro de notice : A2011-058 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30839
in GPS world > vol 22 n° 2 (February 2011) . - pp 40 - 48[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 067-2011021 RAB Revue Centre de documentation En réserve L003 Disponible Collective detection: enhancing GNSS receiver sensitivity by combining signals from multiple satellites / Penina Axelrad in GPS world, vol 21 n° 1 (January 2010)
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Titre : Collective detection: enhancing GNSS receiver sensitivity by combining signals from multiple satellites Type de document : Article/Communication Auteurs : Penina Axelrad, Auteur ; J. Donna, Auteur ; M. Mitchell, Auteur ; S. Mohiuddin, Auteur Année de publication : 2010 Article en page(s) : pp 58 - 64 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] détection du signal
[Termes IGN] fusion de données multisource
[Termes IGN] géonavigateur
[Termes IGN] GNSS assisté pour la navigation
[Termes IGN] GPS-INS
[Termes IGN] positionnement par GNSS
[Termes IGN] qualité du signal
[Termes IGN] traitement du signalRésumé : (Auteur) [...] Poor signal reception in other than open-sky environments is still a problem with conventional GPS receivers. However, extending signal integration times and using assisted-GPS techniques can give GPS some degree of capability to operate indoors and in other restricted environments, albeit typically with reduced positioning accuracy. An antenna with sufficient gain is needed and capable systems are available on the market. The pilot channels of modernized GNSS signals will also benefit signal acquisition and tracking in challenging environments.
In this month's column, we look at a completely different approach to enhancing signal sensitivity. Rather than requiring each satellite's signal to be acquired and tracked before it can be used in the navigation solution, the new approach dubbed "collective detection" combines the received signal power from multiple satellites in a direct-to-navigation-solution procedure. Besides providing a quick coarse position solution with weak signals, this approach can be used to monitor the signal environment, aid deeply-coupled GPS/inertial navigation, and assist with terrain and feature recognition. Copyright Questex Media GroupNuméro de notice : A2010-019 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30215
in GPS world > vol 21 n° 1 (January 2010) . - pp 58 - 64[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 067-2010011 RAB Revue Centre de documentation En réserve L003 Disponible One year in orbit: GIOVE-B E1 CBOC signal quality assessment / M. Sollner in GPS world, vol 20 n° 9 (September 2009)
[article]
Titre : One year in orbit: GIOVE-B E1 CBOC signal quality assessment Type de document : Article/Communication Auteurs : M. Sollner, Auteur ; C. Kurzhals, Auteur ; W. Kogler, Auteur ; et al., Auteur Année de publication : 2009 Article en page(s) : 8 p. ; pp 28 - 38 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] qualité du signal
[Termes IGN] signal GNSS
[Termes IGN] test de performanceRésumé : (Editeur) The second GALILEO test satellite, GIOVE-B, was launched on April 27,2008, and began transmitting navigation signals a few days later. It joined its older sibling, GIOVE-A, which was placed in orbit over two years earlier. [...] The launches are expected to occur by the end of 2010. But before the In-Orbit Validation (IOV) phase can begin, a thorough analysis of the performance of the GIOVE satellites must be carried out to minimize any difficulties with the IOV satellites. This includes monitoring and assessing the different signals broadcast by the satellites. The GIOVE satellites can transmit on all three Galileo frequencies, E5, E6, and E1 (also known as L1) but only on two simultaneously (either E1-E5 or E1-E6). A variety of modulation types can be transmitted on the different frequencies by both satellites to test their use for the different Galileo services to be implemented for the operational constellation. These include alternative binary offset carrier (BOC) and quadrature phase shift keying on E5 and cosine BOC (BOCc) and binary phase shift keying on E6. On E1, the satellites have different capabilities. Although both satellites can transmit BOCc on this frequency, GIOVE-A can additionally transmit a single BOC signal with a subcarrier frequency of 1.023 MHz and a spreading code chipping rate of 1.023 MHz (BOC(1,1)) whereas GIOVE-B transmits a more versatile multiplexed composite BOC or CBOC, which linearly combines BOC(1,1) and BOC(6,1). The CBOC signal is being transmitted by GIOVE-B to explore its performance, usability, and any possible side effects including its use in receivers designed to track a BOC(1,1) signal. GIOVE-B has now been in orbit for just over one year. How well is it performing? In particular, what can we say about one of GIOVE-B's pioneering features: its E1 CBOC signal? In this month's column, we take a detailed look at a particular monitoring and assessment program set up to examine the GIOVE-B signals and discuss some of its initial CBOC results. The successful operation of this program bodes well for its use in future validation campaigns. Copyright Questex Media Group Numéro de notice : A2009-348 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29978
in GPS world > vol 20 n° 9 (September 2009) . - 8 p. ; pp 28 - 38[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 067-09091 SL Revue Centre de documentation Revues en salle Disponible