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ERTK: extra-wide-lane RTK of triple-frequency GNSS signals / Bofeng Li in Journal of geodesy, vol 91 n° 9 (September 2017)
[article]
Titre : ERTK: extra-wide-lane RTK of triple-frequency GNSS signals Type de document : Article/Communication Auteurs : Bofeng Li, Auteur ; Zhen Li, Auteur ; Zhiteng Zhang, Auteur ; Yu’an Tan, Auteur Année de publication : 2017 Article en page(s) : pp 1031 – 1047 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse comparative
[Termes IGN] données BeiDou
[Termes IGN] données Galileo
[Termes IGN] filtrage du signal
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] précision centimétrique
[Termes IGN] propagation ionosphérique
[Termes IGN] récepteur trifréquence
[Termes IGN] résolution d'ambiguïté
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Triple-frequency signals have thus far been available for all satellites of BeiDou and Galileo systems and for some GPS satellites. The main benefit of triple-frequency signals is their formation of extra-wide-lane (EWL) combinations whose ambiguities can be instantaneously fixed for several 10–100 km baselines. Yet, this benefit has not been fully exploited and only used as a constraint for narrow-lane (NL) ambiguity resolution (AR) in most previous studies. In this study, we comprehensively investigate the real-time kinematic (RTK) capabilities of EWL observations, also referred to as EWL RTK (ERTK). We begin by mathematically expressing the ease of EWL AR and the difficulty of NL AR, respectively, using a numerical demonstration. We then present the mathematical models for ERTK including the ionosphere-ignored, ionosphere-float and ionosphere-smoothed types. The experiments are conducted using a four-station network of real triple-frequency BeiDou data with baseline lengths from 33 to 75 km. The results show that the ionosphere-ignored ERTK achieves real-time solutions with a horizontal accuracy of about 10 cm. Although the ionosphere-float ERTK solutions are very noisy, they can be quickly improved at the centimetre level by further applying the ionosphere-smoothed model. Note that such accurate results are very promising and already satisfy many applications without complicated NL AR. To the best of our knowledge, this is the first comprehensive study to make full use of EWL observations of triple-frequency signals on RTK. Numéro de notice : A2017-464 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1006-1 En ligne : https://doi.org/10.1007/s00190-017-1006-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86410
in Journal of geodesy > vol 91 n° 9 (September 2017) . - pp 1031 – 1047[article]Improving BeiDou real-time precise point positioning with numerical weather models / Cuixian Lu in Journal of geodesy, vol 91 n° 9 (September 2017)
[article]
Titre : Improving BeiDou real-time precise point positioning with numerical weather models Type de document : Article/Communication Auteurs : Cuixian Lu, Auteur ; Xingxing Li, Auteur ; Florian Zus, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 1019–1029 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] données BeiDou
[Termes IGN] données météorologiques
[Termes IGN] positionnement ponctuel précis
[Termes IGN] précision du positionnement
[Termes IGN] retard troposphérique
[Termes IGN] temps réel
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) Precise positioning with the current Chinese BeiDou Navigation Satellite System is proven to be of comparable accuracy to the Global Positioning System, which is at centimeter level for the horizontal components and sub-decimeter level for the vertical component. But the BeiDou precise point positioning (PPP) shows its limitation in requiring a relatively long convergence time. In this study, we develop a numerical weather model (NWM) augmented PPP processing algorithm to improve BeiDou precise positioning. Tropospheric delay parameters, i.e., zenith delays, mapping functions, and horizontal delay gradients, derived from short-range forecasts from the Global Forecast System of the National Centers for Environmental Prediction (NCEP) are applied into BeiDou real-time PPP. Observational data from stations that are capable of tracking the BeiDou constellation from the International GNSS Service (IGS) Multi-GNSS Experiments network are processed, with the introduced NWM-augmented PPP and the standard PPP processing. The accuracy of tropospheric delays derived from NCEP is assessed against with the IGS final tropospheric delay products. The positioning results show that an improvement in convergence time up to 60.0 and 66.7% for the east and vertical components, respectively, can be achieved with the NWM-augmented PPP solution compared to the standard PPP solutions, while only slight improvement in the solution convergence can be found for the north component. A positioning accuracy of 5.7 and 5.9 cm for the east component is achieved with the standard PPP that estimates gradients and the one that estimates no gradients, respectively, in comparison to 3.5 cm of the NWM-augmented PPP, showing an improvement of 38.6 and 40.1%. Compared to the accuracy of 3.7 and 4.1 cm for the north component derived from the two standard PPP solutions, the one of the NWM-augmented PPP solution is improved to 2.0 cm, by about 45.9 and 51.2%. The positioning accuracy for the up component improves from 11.4 and 13.2 cm with the two standard PPP solutions to 8.0 cm with the NWM-augmented PPP solution, an improvement of 29.8 and 39.4%, respectively. Numéro de notice : A2017-463 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1005-2 En ligne : https://doi.org/10.1007/s00190-017-1005-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86409
in Journal of geodesy > vol 91 n° 9 (September 2017) . - pp 1019–1029[article]Maintaining real-time precise point positioning during outages of orbit and clock corrections / Ahmed El-Mowafy in GPS solutions, vol 21 n° 3 (July 2017)
[article]
Titre : Maintaining real-time precise point positioning during outages of orbit and clock corrections Type de document : Article/Communication Auteurs : Ahmed El-Mowafy, Auteur ; Manoj Deo, Auteur ; Nobuaki Kubo, Auteur Année de publication : 2017 Article en page(s) : pp 937 – 947 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] horloge
[Termes IGN] International GNSS Service
[Termes IGN] international GPS service for geodynamics
[Termes IGN] interruption du signal
[Termes IGN] orbitographie
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] positionnement ponctuel précis
[Termes IGN] précision décimétrique
[Termes IGN] prévisionRésumé : (auteur) The precise point positioning (PPP) is a popular positioning technique that is dependent on the use of precise orbits and clock corrections. One serious problem for real-time PPP applications such as natural hazard early warning systems and hydrographic surveying is when a sudden communication break takes place resulting in a discontinuity in receiving these orbit and clock corrections for a period that may extend from a few minutes to hours. A method is presented to maintain real-time PPP with 3D accuracy less than a decimeter when such a break takes place. We focus on the open-access International GNSS Service (IGS) real-time service (RTS) products and propose predicting the precise orbit and clock corrections as time series. For a short corrections outage of a few minutes, we predict the IGS-RTS orbits using a high-order polynomial, and for longer outages up to 3 h, the most recent IGS ultra-rapid orbits are used. The IGS-RTS clock corrections are predicted using a second-order polynomial and sinusoidal terms. The model parameters are estimated sequentially using a sliding time window such that they are available when needed. The prediction model of the clock correction is built based on the analysis of their properties, including their temporal behavior and stability. Evaluation of the proposed method in static and kinematic testing shows that positioning precision of less than 10 cm can be maintained for up to 2 h after the break. When PPP re-initialization is needed during the break, the solution convergence time increases; however, positioning precision remains less than a decimeter after convergence. Numéro de notice : A2017-442 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-016-0583-4 En ligne : https://doi.org/10.1007/s10291-016-0583-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86360
in GPS solutions > vol 21 n° 3 (July 2017) . - pp 937 – 947[article]Ne plus négliger le recul des falaises méditerranéennes / Marielle Mayo in Géomètre, n° 2149 (juillet - août 2017)
[article]
Titre : Ne plus négliger le recul des falaises méditerranéennes Type de document : Article/Communication Auteurs : Marielle Mayo, Auteur Année de publication : 2017 Article en page(s) : pp 46 - 49 Langues : Français (fre) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] analyse diachronique
[Termes IGN] Bureau de recherches géologiques et minières
[Termes IGN] données lidar
[Termes IGN] effondrement de terrain
[Termes IGN] gestion des risques
[Termes IGN] littoral méditerranéen
[Termes IGN] orthoimage
[Termes IGN] précision centimétrique
[Termes IGN] surveillance du littoralRésumé : (auteur) Minimisé par des habitants trop confiants, le risque lié à l'érosion a été confirmé par le projet Valse, qui a mis en lumière le grignotage de la côte depuis des millénaires. Numéro de notice : A2017-393 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85908
in Géomètre > n° 2149 (juillet - août 2017) . - pp 46 - 49[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 063-2017071 RAB Revue Centre de documentation En réserve L003 Disponible Review of code and phase biases in multi-GNSS positioning / Martin Håkansson in GPS solutions, vol 21 n° 3 (July 2017)
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Titre : Review of code and phase biases in multi-GNSS positioning Type de document : Article/Communication Auteurs : Martin Håkansson, Auteur ; Anna B. O. Jensen, Auteur ; Milan Horemuz, Auteur ; Gunnar Hedling, Auteur Année de publication : 2017 Article en page(s) : pp 849 - 860 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] code GNSS
[Termes IGN] correction du signal
[Termes IGN] données GNSS
[Termes IGN] modèle ionosphérique
[Termes IGN] phase GNSS
[Termes IGN] positionnement par GNSS
[Termes IGN] précision du positionnement
[Termes IGN] récepteur GNSS
[Termes IGN] résolution d'ambiguïtéRésumé : (auteur) A review of the research conducted until present on the subject of Global Navigation Satellite System (GNSS) hardware-induced phase and code biases is here provided. Biases in GNSS positioning occur because of imperfections and/or physical limitations in the GNSS hardware. The biases are a result of small delays between events that ideally should be simultaneous in the transmission of the signal from a satellite or in the reception of the signal in a GNSS receiver. Consequently, these biases will also be present in the GNSS code and phase measurements and may there affect the accuracy of positions and other quantities derived from the observations. For instance, biases affect the ability to resolve the integer ambiguities in Precise Point Positioning (PPP), and in relative carrier phase positioning when measurements from multiple GNSSs are used. In addition, code biases affect ionospheric modeling when the Total Electron Content is estimated from GNSS measurements. The paper illustrates how satellite phase biases inhibit the resolution of the phase ambiguity to an integer in PPP, while receiver phase biases affect multi-GNSS positioning. It is also discussed how biases in the receiver channels affect relative GLONASS positioning with baselines of mixed receiver types. In addition, the importance of code biases between signals modulated onto different carriers as is required for modeling the ionosphere from GNSS measurements is discussed. The origin of biases is discussed along with their effect on GNSS positioning, and descriptions of how biases can be estimated or in other ways handled in the positioning process are provided. Numéro de notice : A2017-438 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-016-0572-7 En ligne : https://doi.org/10.1007/s10291-016-0572-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86348
in GPS solutions > vol 21 n° 3 (July 2017) . - pp 849 - 860[article]PermalinkLes géomètres du CERN et les faisceaux de particules / Dominique Missiaen in Géomètre, n° 2148 (juin 2017)PermalinkGNSS antenna caused near-field interference effect in Precise Point Positioning results / Karol Dawidowicz in Artificial satellites, vol 52 n° 2 (June 2017)PermalinkEvaluation of the range accuracy and the radiometric calibration of multiple terrestrial laser scanning instruments for data interoperability / Kim Calders in IEEE Transactions on geoscience and remote sensing, vol 55 n° 5 (May 2017)PermalinkGalileo face à une panne d'horloge / Anonyme in Géomètre, n° 2147 (mai 2017)PermalinkControl quality of open source Digital Elevation Models (DEMs) in Tunisia / Noamen Rebaï in Revue internationale de géomatique, vol 27 n° 2 (avril - juin 2017)PermalinkPrecision on board : orbit determination of LEO satellites with real-time corrections / André Hauschild in GPS world, vol 28 n° 4 (April 2017)PermalinkLa BD Topage prend source / Marielle Mayo in Géomètre, n° 2145 (mars 2017)PermalinkBias compensation for rational function model based on total least squares / Anzhu Yu in Photogrammetric record, vol 32 n° 157 (March - May 2017)PermalinkCalcul du quasi-géoïde QGF16 et de la grille de conversion altimétrique RAF16 : état d'avancement et perspectives / François L'écu in XYZ, n° 150 (mars - mai 2017)Permalink