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Evaluating the performance of using PPK-GPS technique in producing topographic contour map / Ahmed El Shouny in Marine geodesy, vol 40 n° 4 (July 2017)
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Titre : Evaluating the performance of using PPK-GPS technique in producing topographic contour map Type de document : Article/Communication Auteurs : Ahmed El Shouny, Auteur ; Nagy Yakoub, Auteur ; Magdy Hosny, Auteur Année de publication : 2017 Article en page(s) : pp 224 - 238 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] altitude orthométrique
[Termes IGN] analyse comparative
[Termes IGN] carte topographique
[Termes IGN] courbe de niveau
[Termes IGN] données GPS
[Termes IGN] Egypte
[Termes IGN] GPS en mode différentiel
[Termes IGN] Nil (delta du)
[Termes IGN] niveau à bulle
[Termes IGN] post-traitement
[Vedettes matières IGN] AltimétrieRésumé : (Auteur) The Global Positioning System (GPS) is considered as one of the most powerful tools that are used in geodetic works. It is increasingly considered as an alternative tool for conventional surveying techniques. The goal of this research paper is to produce a methodology for generating topographic contour maps using the post-processed kinematic differential GPS technique (PPK-GPS). The performance of this technique is assessed by comparing it with the traditional spirit-leveling technique taking into consideration the accuracy, time, and cost. The study area is located along the Mediterranean coast in the Rosetta area of the middle Delta in Egypt with a total area of about 39 km2. The field work includes 14 control points and about 50,000 PPK observations. In addition, 20 check cross sections that extend along the coastal line from Rosetta to El Burullus cities were observed using both spirit-leveling and GPS-PPK techniques. The results of the comparison indicate that the PPK-GPS technique can be used instead of spirit leveling in producing a topographic contour map with an accuracy of about 20 cm in orthometric height. We find that the PPK-GPS technique reduces the estimated time of leveling works in our study area by about 70%. Numéro de notice : A2017-667 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1080/01490419.2017.1321594 En ligne : https://doi.org/10.1080/01490419.2017.1321594 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=87142
in Marine geodesy > vol 40 n° 4 (July 2017) . - pp 224 - 238[article]A framework for interactive visual analysis of heterogeneous marine data in an integrated problem solving environment / Shuai Liu in Computers & geosciences, vol 104 (July 2017)
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Titre : A framework for interactive visual analysis of heterogeneous marine data in an integrated problem solving environment Type de document : Article/Communication Auteurs : Shuai Liu, Auteur ; Ge Chen, Auteur ; Shifeng Yao, Auteur ; Fenglin Tian, Auteur ; Wei Liu, Auteur Année de publication : 2017 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] base de données marines
[Termes IGN] carte interactive
[Termes IGN] données spatiotemporelles
[Termes IGN] environnement géographique virtuel
[Termes IGN] monde virtuel
[Termes IGN] océanographie spatiale
[Termes IGN] positionnement par Argos
[Termes IGN] visualisation de données
[Vedettes matières IGN] GéovisualisationRésumé : (auteur) This paper presents a novel integrated marine visualization framework which focuses on processing, analyzing the multi-dimension spatiotemporal marine data in one workflow. Effective marine data visualization is needed in terms of extracting useful patterns, recognizing changes, and understanding physical processes in oceanography researches. However, the multi-source, multi-format, multi-dimension characteristics of marine data pose a challenge for interactive and feasible (timely) marine data analysis and visualization in one workflow. And, global multi-resolution virtual terrain environment is also needed to give oceanographers and the public a real geographic background reference and to help them to identify the geographical variation of ocean phenomena. This paper introduces a data integration and processing method to efficiently visualize and analyze the heterogeneous marine data. Based on the data we processed, several GPU-based visualization methods are explored to interactively demonstrate marine data. GPU-tessellated global terrain rendering using ETOPO1 data is realized and the video memory usage is controlled to ensure high efficiency. A modified ray-casting algorithm for the uneven multi-section Argo volume data is also presented and the transfer function is designed to analyze the 3D structure of ocean phenomena. Based on the framework we designed, an integrated visualization system is realized. The effectiveness and efficiency of the framework is demonstrated. This system is expected to make a significant contribution to the demonstration and understanding of marine physical process in a virtual global environment. Numéro de notice : A2017-128 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.cageo.2017.03.021 En ligne : http://doi.org/10.1016/j.cageo.2017.03.021 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84543
in Computers & geosciences > vol 104 (July 2017)[article]Future Space Service of NavIC (IRNSS) Constellation / Parimal Majithiya in Inside GNSS, vol 12 n° 4 (July - August 2017)
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Titre : Future Space Service of NavIC (IRNSS) Constellation Type de document : Article/Communication Auteurs : Parimal Majithiya, Auteur ; Kriti Khatri, Auteur ; S.C. Bera, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 40 - 45 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] antenne
[Termes IGN] Indian Regional Navigation Satellite System
[Termes IGN] signal GNSSRésumé : (auteur) Today many satellite-based navigation systems are providing terrestrial services. In the near future these systems will also contribute for space service. In this article, we’ll discuss navigation service parameters and Space Service Volume (SSV) for the Indian Regional Navigation Satellite System (IRNSS) constellation now known as NavIC (Navigation with Indian Constellation). The simulations are carried out to derive the received signal power level and availability of the number of satellites for users in Geosynchronous Earth Orbit (GEO), High Earth Orbit (HEO), and Medium Earth Orbit (MEO) satellites. Based on antenna characteristics, the IRNSS SSV is defined and simulated. The group delay parameter considerations are also discussed for this service. Here we’ll take a look at the contribution of the NavIC constellation in future space services. Numéro de notice : A2017-582 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans En ligne : http://www.insidegnss.com/node/5568 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86716
in Inside GNSS > vol 12 n° 4 (July - August 2017) . - pp 40 - 45[article]Impact of GPS differential code bias in dual- and triple-frequency positioning and satellite clock estimation / Haojun Li in GPS solutions, vol 21 n° 3 (July 2017)
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Titre : Impact of GPS differential code bias in dual- and triple-frequency positioning and satellite clock estimation Type de document : Article/Communication Auteurs : Haojun Li, Auteur ; Bofeng Li, Auteur ; Lizhi Lou, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 897 – 903 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] code GPS
[Termes IGN] erreur corrélée au temps
[Termes IGN] erreur systématique
[Termes IGN] géodésie spatiale
[Termes IGN] GPS en mode différentiel
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur bifréquence
[Termes IGN] récepteur trifréquence
[Termes IGN] retard ionosphèriqueRésumé : (auteur) The features and differences of various GPS differential code bias (DCB)s are discussed. The application of these biases in dual- and triple-frequency satellite clock estimation is introduced based on this discussion. A method for estimating the satellite clock error from triple-frequency uncombined observations is presented to meet the need of the triple-frequency uncombined precise point positioning (PPP). In order to evaluate the estimated satellite clock error, the performance of these biases in dual- and triple-frequency positioning is studied. Analysis of the inter-frequency clock bias (IFCB), which is a result of constant and time-varying frequency-dependent hardware delays, in ionospheric-free code-based (P1/P5) single point positioning indicates that its influence on the up direction is more pronounced than on the north and east directions. When the IFCB is corrected, the mean improvements are about 29, 35 and 52% for north, east and up directions, respectively. Considering the contribution of code observations to PPP convergence time, the performance of DCB(P1–P2), DCB(P1–P5) and IFCB in GPS triple-frequency PPP convergence is investigated. The results indicate that the DCB correction can accelerate PPP convergence by means of improving the accuracy of the code observation. The performance of these biases in positioning further verifies the correctness of the estimated dual- and triple-frequency satellite clock error. Numéro de notice : A2017-441 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-016-0578-1 En ligne : https://doi.org/10.1007/s10291-016-0578-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86358
in GPS solutions > vol 21 n° 3 (July 2017) . - pp 897 – 903[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)
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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)
PermalinkNew optimal smoothing scheme for improving relative and absolute accuracy of tightly coupled GNSS/SINS integration / Xiaohong Zhang in GPS solutions, vol 21 n° 3 (July 2017)
PermalinkReal-time precise point positioning augmented with high-resolution numerical weather prediction model / Karina Wilgan in GPS solutions, vol 21 n° 3 (July 2017)
PermalinkReview of code and phase biases in multi-GNSS positioning / Martin Håkansson in GPS solutions, vol 21 n° 3 (July 2017)
PermalinkRobust GPS/BDS/INS tightly coupled integration with atmospheric constraints for long-range kinematic positioning / Houzeng Han in GPS solutions, vol 21 n° 3 (July 2017)
Permalinkvol 21 n° 3 - July - September 2017 - Special issue [included] on Map interaction (Bulletin de Geoinformatica) / Christian Kray
PermalinkStatistical comparison and combination of GPS, GLONASS, and multi-GNSS multipath reflectometry applied to snow depth retrieval / Sajad Tabibi in IEEE Transactions on geoscience and remote sensing, vol 55 n° 7 (July 2017)
PermalinkStudy on GPS–PPP precision for short observation sessions / Stefano Gandolfi in GPS solutions, vol 21 n° 3 (July 2017)
PermalinkAn example and analysis for ambiguity resolution in the indoor ZigBee positioning system / Joanna Janicka in Reports on geodesy and geoinformatics, vol 103 n° 1 (June 2017)
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