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A quelles altitudes se trouvent les horloges atomiques de l'observatoire de Paris ? / Xavier Collilieux in XYZ, n° 156 (septembre - novembre 2018)
[article]
Titre : A quelles altitudes se trouvent les horloges atomiques de l'observatoire de Paris ? Type de document : Article/Communication Auteurs : Xavier Collilieux , Auteur ; Pacôme Delva, Auteur ; Laurent Heydel , Auteur ; Guillaume Lion , Auteur ; Fabien Bergerault, Auteur ; Raphaëlle Delaugerre, Auteur ; Loïc Evrard, Auteur ; Sylvain Gonnet, Auteur ; Damien Pesce, Auteur ; Patrice Prezat, Auteur Année de publication : 2018 Projets : 1-Pas de projet / Article en page(s) : pp 26 - 30 Note générale : Bibliographie Langues : Français (fre) Descripteur : [Termes IGN] altitude
[Termes IGN] chronométrie
[Termes IGN] fréquence
[Termes IGN] horloge atomique
[Termes IGN] métrologie
[Termes IGN] nivellement direct
[Termes IGN] Observatoire de Paris
[Termes IGN] positionnement par GNSS
[Termes IGN] potentiel de pesanteur terrestre
[Vedettes matières IGN] AltimétrieRésumé : (Auteur) L’exactitude des horloges optiques permet d’envisager dans le futur leur utilisation pour déterminer des différences d’altitudes à une précision centimétrique. Les développements actuels consistent à comparer les fréquences d’horloges en cours de développement. Ainsi, la mise en place de protocoles de comparaison constitue une première étape. Aujourd’hui, c’est encore au géomètre, au moyen des techniques traditionnelles, de déterminer l’altitude des horloges pour permettre ces comparaisons et fournir une mesure de référence. Cet article décrit les opérations de nivellement effectuées par l’IGN à l’Observatoire de Paris dans le contexte de projets scientifiques européens impliquant le laboratoire SYRTE de l’Observatoire de Paris. Numéro de notice : A2018-394 Affiliation des auteurs : ENSG+Ext (2012-2019) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueNat DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90830
in XYZ > n° 156 (septembre - novembre 2018) . - pp 26 - 30[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 112-2018031 RAB Revue Centre de documentation En réserve L003 Disponible Determining inter-system bias of GNSS signals with narrowly spaced frequencies for GNSS positioning / Yumiao Tian in Journal of geodesy, vol 92 n° 8 (August 2018)
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Titre : Determining inter-system bias of GNSS signals with narrowly spaced frequencies for GNSS positioning Type de document : Article/Communication Auteurs : Yumiao Tian, Auteur ; Zhizhao Liu, Auteur ; Maorong Ge, Auteur ; Frank Neitzel, Auteur Année de publication : 2018 Article en page(s) : pp 873 - 887 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] ambiguïté entière
[Termes IGN] double différence
[Termes IGN] erreur systématique inter-systèmes
[Termes IGN] fréquence
[Termes IGN] positionnement par GNSS
[Termes IGN] signal GLONASS
[Termes IGN] signal GNSS
[Termes IGN] signal GPSRésumé : (Auteur) Relative positioning using multi-GNSS (global navigation satellite systems) can improve accuracy, reliability, and availability compared to the use of a single constellation system. Intra-system double-difference (DD) ambiguities (ISDDAs) refer to the DD ambiguities between satellites of a single constellation system and can be fixed to an integer to derive the precise fixed solution. Inter-system ambiguities, which denote the DD ambiguities between different constellation systems, can also be fixed to integers on overlapping frequencies, once the inter-system bias (ISB) is removed. Compared with fixing ISDDAs, fixing both integer intra- and inter-system DD ambiguities (IIDDAs) means an increase of positioning precision through an integration of multiple GNSS constellations. Previously, researchers have studied IIDDA fixing with systems of the same frequencies, but not with systems of different frequencies. Integer IIDDAs can be determined from single-difference (SD) ambiguities, even if the frequencies of multi-GNSS signals used in the positioning are different. In this study, we investigated IIDDA fixing for multi-GNSS signals of narrowly spaced frequencies. First, the inter-system DD models of multi-GNSS signals of different frequencies are introduced, and the strategy for compensating for ISB is presented. The ISB is decomposed into three parts: 1) a float approximate ISB number that can be considered equal to the ISB of code pseudorange observations and thus can be estimated through single point positioning (SPP); 2) a number that is a multiple of the GNSS signal wavelength; and 3) a fractional ISB part, with a magnitude smaller than a single wavelength. Then, the relationship between intra- and inter-system DD ambiguity RATIO values and ISB was investigated by integrating GPS L1 and GLONASS L1 signals. In our numerical analyses with short baselines, the ISB parameter and IIDDA were successfully fixed, even if the number of observed satellites in each system was small. Numéro de notice : A2018-456 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1100-4 Date de publication en ligne : 14/12/2017 En ligne : https://doi.org/10.1007/s00190-017-1100-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91053
in Journal of geodesy > vol 92 n° 8 (August 2018) . - pp 873 - 887[article]Comparative analysis of multi-constellation GNSS single-frequency precise point positioning / Mahmoud Abd Rabbou in Survey review, vol 50 n° 361 (July 2018)
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Titre : Comparative analysis of multi-constellation GNSS single-frequency precise point positioning Type de document : Article/Communication Auteurs : Mahmoud Abd Rabbou, Auteur ; Adel El-Shazly, Auteur ; Kamal Ahmed, Auteur Année de publication : 2018 Article en page(s) : pp 373 - 382 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] analyse comparative
[Termes IGN] positionnement par BeiDou
[Termes IGN] positionnement par Galileo
[Termes IGN] positionnement par GLONASS
[Termes IGN] positionnement par GPS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur GNSS
[Termes IGN] récepteur monofréquenceRésumé : (Auteur) We develop new single-frequency PPP models, which combine the observations of the current GNSS constellations, including GPS, GLONASS, Galileo and BeiDou. Four single-frequency GNSS PPP models are developed, namely, the undifferenced single-frequency GNSS PPP model, the undifferenced ionosphere-free (IF) code and phase model known as quasi-phase model, the between-satellite-single-difference model (BSSD) and the between-satellite-single-difference ionosphere-free (BSSDIF) model. The IGS final precise products are used to account for the orbital and clock errors. For both undifferenced and BSSD models, the IGS final global ionospheric maps (GIM) model is used to correct the ionospheric delay. The GNSS inter-system biases are treated as additional unknowns in the estimation process for the undifferenced models, while a loosely coupled technique is used for the BSSD models. Various GNSS combinations are considered in the assessment for each PPP model, including GPS/GLONASS, GPS/Galileo, GPS/BeiDou and quad-constellation GNSS observations. It is shown that the multi-GNSS observations enhance the PPP solution accuracy in comparison with the GPS-only solution. Furthermore, the use of IF-PPP technique enhances the positioning accuracy by 25, 20, 24, 20 and 19% compared with the GIM-based PPP model for the GPS-only, GPS/GLONASS, GPS/Galileo, GPS/BeiDou and quad-GNSS combinations, respectively, for 1 h of GNSS data processing. In addition, an average of 15% positioning accuracy improvement can be obtained when the BSSD techniques are used compared with the undifferenced techniques. However, for 6 h of processing, comparable positioning accuracy can be obtained from all four single-frequency models. Numéro de notice : A2018-445 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00396265.2017.1296628 Date de publication en ligne : 13/03/2017 En ligne : https://doi.org/10.1080/00396265.2017.1296628 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91030
in Survey review > vol 50 n° 361 (July 2018) . - pp 373 - 382[article]Differential positioning based on the orthogonal transformation algorithm with GNSS multi-system / Xiao Liang in GPS solutions, vol 22 n° 3 (July 2018)
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Titre : Differential positioning based on the orthogonal transformation algorithm with GNSS multi-system Type de document : Article/Communication Auteurs : Xiao Liang, Auteur ; Zhigang Huang, Auteur ; Honglei Qin, Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] ambiguïté entière
[Termes IGN] erreur instrumentale
[Termes IGN] erreur systématique
[Termes IGN] filtre de Kalman
[Termes IGN] méthode des moindres carrés
[Termes IGN] positionnement différentiel
[Termes IGN] résolution d'ambiguïté
[Termes IGN] simple différence
[Vedettes matières IGN] Traitement de données GNSSRésumé : (Auteur) Combining global navigation satellite systems (GNSSs) will significantly increase the number of visible satellites and, thus, will improve the geometry of observed satellites, resulting in improved positioning reliability and accuracy. We focus on GNSS multi-system differential positioning based on a single-system orthogonal transformation algorithm. The orthogonal transformation algorithm using single-difference measurements is proposed to avoid the high correlation between measurements and the unnecessary prominence to the reference satellite in double-difference positioning. In addition, the algorithm uses a more straightforward recursive least squares method to avoid the effect of uncertainties of the Kalman filter. We discuss the model differences between combined system positioning and single-system positioning and verify that the combining observations of different systems should start to be used after clock biases have been reduced, respectively. Moreover, as to rising and setting of satellites in multi-system differential positioning, we propose to use matrix transform to separate the setting satellites of combined systems at an epoch. This can avoid the correlation of initial integer ambiguity vectors of different systems. The experimental results show that the proposed method can handle the change of satellites automatically and combine multiple systems for reliable and accuracy differential positioning. The method especially outperforms the basic single-system orthogonal transformation positioning and traditional multi-system double-difference positioning in a complex environment. Numéro de notice : A2018-371 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-018-0754-6 Date de publication en ligne : 02/07/2018 En ligne : https://doi.org/10.1007/s10291-018-0754-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90763
in GPS solutions > vol 22 n° 3 (July 2018)[article]A fully automatic approach to register mobile mapping and airborne imagery to support the correction of plateform trajectories in GNSS-denied urban areas / Phillipp Jende in ISPRS Journal of photogrammetry and remote sensing, vol 141 (July 2018)
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Titre : A fully automatic approach to register mobile mapping and airborne imagery to support the correction of plateform trajectories in GNSS-denied urban areas Type de document : Article/Communication Auteurs : Phillipp Jende, Auteur ; Francesco Nex, Auteur ; Markus Gerke, Auteur ; M. George Vosselman, Auteur Année de publication : 2018 Article en page(s) : pp 86 - 99 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] appariement géométrique
[Termes IGN] extraction de traits caractéristiques
[Termes IGN] filtre de Wallis
[Termes IGN] GNSS assisté pour la navigation
[Termes IGN] image aérienne
[Termes IGN] image terrestre
[Termes IGN] orientation d'image
[Termes IGN] orthoimage
[Termes IGN] point d'appui
[Termes IGN] précision décimétrique
[Termes IGN] système de numérisation mobile
[Termes IGN] zone urbaineRésumé : (Auteur) Mobile Mapping (MM) solutions have become a significant extension to traditional data acquisition methods over the last years. Independently from the sensor carried by a platform, may it be laser scanners or cameras, high-resolution data postings are opposing a poor absolute localisation accuracy in urban areas due to GNSS occlusions and multipath effects. Potentially inaccurate position estimations are propagated by IMUs which are furthermore prone to drift effects. Thus, reliable and accurate absolute positioning on a par with MM's high-quality data remains an open issue. Multiple and diverse approaches have shown promising potential to mitigate GNSS errors in urban areas, but cannot achieve decimetre accuracy, require manual effort, or have limitations with respect to costs and avail-ability. This paper presents a fully automatic approach to support the correction of MM imaging data based on correspondences with airborne nadir images. These correspondences can be employed to correct the MM plat-form's orientation by an adjustment solution. Unlike MM as such, aerial images do not suffer from GNSS oc-clusions, and their accuracy is usually verified by employing well-established methods using ground control points. However, a registration between MM and aerial images is a non-standard matching scenario, and requires several strategies to yield reliable and accurate correspondences. Scale, perspective and content strongly vary between both image sources, thus traditional feature matching methods may fail. To this end, the registration process is designed to focus on common and clearly distinguishable elements, such as road markings, manholes, or kerbstones. With a registration accuracy of about 98%, reliable tie information between MM and aerial data can be derived. Even though, the adjustment strategy is not covered in its entirety in this paper, accuracy results after adjustment will be presented. It will be shown that a decimetre accuracy is well achievable in a real data test scenari Numéro de notice : A2018-285 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2018.04.017 Date de publication en ligne : 30/04/2018 En ligne : https://doi.org/10.1016/j.isprsjprs.2018.04.017 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90397
in ISPRS Journal of photogrammetry and remote sensing > vol 141 (July 2018) . - pp 86 - 99[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2018071 RAB Revue Centre de documentation En réserve L003 Disponible 081-2018073 DEP-EXM Revue LASTIG Dépôt en unité Exclu du prêt 081-2018072 DEP-EAF Revue Nancy Dépôt en unité Exclu du prêt Odometer, low-cost inertial sensors, and four-GNSS data to enhance PPP and attitude determination / Zhouzheng Gao in GPS solutions, vol 22 n° 3 (July 2018)PermalinkPositioning stability improvement with inter-system biases on multi-GNSS PPP / Byung-Kyu Choi in Journal of applied geodesy, vol 12 n° 3 (July 2018)PermalinkPrecise orbit determination of the Sentinel-3A altimetry satellite using ambiguity-fixed GPS carrier phase observations / Oliver Montenbruck in Journal of geodesy, vol 92 n° 7 (July 2018)PermalinkWestern Pyrenees geodetic deformation study using the Guipuzcoa GNSS network / Adriana Martin in Journal of applied geodesy, vol 12 n° 3 (July 2018)PermalinkAdvancement of close range photogrammetry with a portable panoramic image mapping system (PPIMS) / Yung-Chuan Chen in Photogrammetric record, vol 33 n° 162 (June 2018)PermalinkGPS receiver phase biases estimable in PPP-RTK networks : dynamic characterization and impact analysis / Baocheng Zhang in Journal of geodesy, vol 92 n° 6 (June 2018)PermalinkMulti-GNSS phase delay estimation and PPP ambiguity resolution : GPS, BDS, GLONASS, Galileo / Xingxing Li in Journal of geodesy, vol 92 n° 6 (June 2018)PermalinkNavigation hybride en couplage serré associant amers célestes et terrestres par la méthode du plan des sommets / Yves Robin-Jouan in XYZ, n° 155 (juin - août 2018)PermalinkOn the impact of GNSS ambiguity resolution: geometry, ionosphere, time and biases / Amir Khodabandeh in Journal of geodesy, vol 92 n° 6 (June 2018)PermalinkPerformance of absolute real-time multi-GNSS kinematic positioning / Kamil Kazmierski in Artificial satellites, vol 53 n° 2 (June 2018)Permalink