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Fast computation of general forward gravitation problems / Fabien Casenave in Journal of geodesy, vol 90 n° 7 (July 2016)
[article]
Titre : Fast computation of general forward gravitation problems Type de document : Article/Communication Auteurs : Fabien Casenave , Auteur ; Laurent Métivier , Auteur ; Gwendoline Pajot-Métivier , Auteur ; Isabelle Panet , Auteur Année de publication : 2016 Article en page(s) : pp 655 – 675 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] France (géographie physique)
[Termes IGN] masse de la Terre
[Termes IGN] potentiel de pesanteur terrestre
[Termes IGN] vitesseRésumé : (auteur) We consider the well-known problem of the forward computation of the gradient of the gravitational potential generated by a mass density distribution of general 3D geometry. Many methods have been developed for given geometries, and the computation time often appears as a limiting practical issue for considering large or complex problems. In this work, we develop a fast method to carry out this computation, where a tetrahedral mesh is used to model the mass density distribution. Depending on the close- or long-range nature of the involved interactions, the algorithm automatically switches between analytic integration formulae and numerical quadratic formulae, and relies on the Fast Multipole Method to drastically increase the computation speed of the long-range interactions. The parameters of the algorithm are empirically chosen for the computations to be the fastest possible while guarantying a given relative accuracy of the result. Computations that would load many-core clusters for days can now be carried out on a desk computer in minutes. The computation of the contribution of topographical masses to the Earth’s gravitational field at the altitude of the GOCE satellite and over France are proposed as numerical illustrations of the method. Numéro de notice : A2016-427 Affiliation des auteurs : LASTIG LAREG (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-016-0900-2 Date de publication en ligne : 08/04/2016 En ligne : http://dx.doi.org/ 10.1007/s00190-016-0900-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81321
in Journal of geodesy > vol 90 n° 7 (July 2016) . - pp 655 – 675[article]Identifying a low-frequency oscillation in Galileo IOV pseudorange rates / Daniele Borio in GPS solutions, vol 20 n° 3 (July 2016)
[article]
Titre : Identifying a low-frequency oscillation in Galileo IOV pseudorange rates Type de document : Article/Communication Auteurs : Daniele Borio, Auteur ; Ciro Gioia, Auteur ; Neil Mitchison, Auteur Année de publication : 2016 Article en page(s) : pp 363 - 372 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] étalonnage en vol
[Termes IGN] Galileo
[Termes IGN] horloge atomique
[Termes IGN] mesurage de pseudo-distance
[Termes IGN] oscillateur
[Termes IGN] performance
[Termes IGN] vitesseRésumé : (Auteur) Galileo, the European global navigation satellite system, is in its in-orbit validation phase and the four satellites which have been available for some months now have allowed a preliminary analysis of the system performance. Previous studies have showed that Galileo will be able to provide pseudorange measurements more accurate than those provided by GPS. However, a similar improvement was not found for pseudorange rate observations in the velocity domain. This fact stimulated additional analysis of the velocity domain, and, in particular, an unintended oscillatory component was identified as the main error source in the velocity solution. The magnitude of such oscillation is less than 10 cm/s, and its period is in the order of few minutes. A methodology was developed to identify oscillatory components in the Galileo IOV pseudorange rate observables, and it was verified that the measurements from Galileo IOV PFM and Galileo IOV FM2 are affected by a small oscillatory disturbance. This disturbance stems from the architecture adopted for combining the frequency references provided by the two active clocks present in the Galileo satellites. The issue has been solved in Galileo IOV FM3 and Galileo IOV FM4, and the oscillatory component has been eliminated. We also propose a methodology for removing this unwanted component from the final velocity solution and for determining the performance that Galileo will be able to achieve. The analysis shows that Galileo velocity solution will provide a root-mean-square error of about 8 cm/s even in the limited geometry conditions achieved using only four satellites. This shows the potential of Galileo also in the determination of user velocity. Numéro de notice : A2016-630 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-015-0443-7 En ligne : http://dx.doi.org/10.1007/s10291-015-0443-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81833
in GPS solutions > vol 20 n° 3 (July 2016) . - pp 363 - 372[article]Interactive discovery of sequential patterns in time series of wind data / Norhakim Yusof in International journal of geographical information science IJGIS, vol 30 n° 7- 8 (July - August 2016)
[article]
Titre : Interactive discovery of sequential patterns in time series of wind data Type de document : Article/Communication Auteurs : Norhakim Yusof, Auteur ; Raul Zurita-Milla, Auteur ; Menno-Jan Kraak, Auteur ; Bas Retsios, Auteur Année de publication : 2016 Article en page(s) : pp 1486 - 1506 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG
[Termes IGN] carte interactive
[Termes IGN] direction
[Termes IGN] météorologie
[Termes IGN] vent
[Termes IGN] visualisation de données statistiques
[Termes IGN] vitesseRésumé : (Auteur) Wind speed and direction vary over space and time due to the interactions between different pressures and temperature gradients within the atmospheric layers. Near the earth’s surface, these interactions are modulated by topography and artificial structures. Hence, characterizing wind behaviour over large areas and long periods is a complex but essential task for various energy-related applications. In this study, we present a novel approach to discover wind patterns by integrating sequential pattern mining and interactive visualization techniques. The approach relies on the use of the Linear time Closed pattern Miner sequence algorithm in conjunction with a time sliding window that allows the discovery of all sequential patterns present in the data. These patterns are then visualized using integrated 2D and 3D coordinated multiple views and visually explored to gain insight into the characteristics of the wind from a spatial, temporal and attribute (type of wind pattern) point of view. This proposed approach is used to analyse 10 years of hourly wind speed and direction data for 29 weather stations in the Netherlands. The results show that there are 15 main sequential patterns in the data. The spatial task shows that weather stations located in the same region do not necessarily experience similar wind pattern. For within the selected time interval, similar wind patterns can be observed in different stations and in the same station at different times of occurrence. The attribute task discovered that the repetitive occurrences of chosen pattern indicate as regular wind behaviour at different weather stations that persisted continuously over time. The results of these tasks show that the proposed interactive discovery facilitates the understanding of wind dynamics in space and time. Numéro de notice : A2016-316 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2015.1135928 En ligne : http://dx.doi.org/10.1080/13658816.2015.1135928 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80936
in International journal of geographical information science IJGIS > vol 30 n° 7- 8 (July - August 2016) . - pp 1486 - 1506[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 079-2016042 RAB Revue Centre de documentation En réserve L003 Disponible 079-2016041 RAB Revue Centre de documentation En réserve L003 Disponible Measurement of surface changes in a scaled-down landslide model using high-speed stereo image sequences / Tiantian Feng in Photogrammetric Engineering & Remote Sensing, PERS, vol 82 n° 7 (juillet 2016)
[article]
Titre : Measurement of surface changes in a scaled-down landslide model using high-speed stereo image sequences Type de document : Article/Communication Auteurs : Tiantian Feng, Auteur ; Huan Mi, Auteur ; Marco Scaioni, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 547 - 557 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] cartographie d'urgence
[Termes IGN] Chine
[Termes IGN] détection de changement
[Termes IGN] effondrement de terrain
[Termes IGN] gestion prévisionnelle
[Termes IGN] modèle de simulation
[Termes IGN] modèle stéréoscopique
[Termes IGN] photogrammétrie métrologique
[Termes IGN] séquence d'images
[Termes IGN] surveillance géologique
[Termes IGN] vitesseRésumé : (Auteur) Construction of scaled-down landslide models is an important means for landslide study. The objective of this study is to develop an innovative non-contact photogrammetric system to meet the challenge for monitoring the fast surface deformation of a laboratory-simulated landslide, which can detect pre-failure events and the final failure, provide sectional and overall surface deformation patterns, and generate speed maps during the rapid slope failure. We proposed an event detector based on altered surface features in the slower SLRC (single-lensreflex camera) image sequence to detect pre-failure events, while a combined analysis tool used the surface velocity fields and deformation areas based on fast HSCS (high-speed stereocamera system) stereo image sequences to reveal fast-changing landslide behavior during the short final failure. The introduced surface change detector uses the percentage of sliding block areas, percentage of changed features, and average speeds. It successfully detected four pre-failure local collapse events and the final slope failure; the extent of surface changes reached its maximum to accumulate energy 1.5 seconds before the failure when the average speed of changed features achieved its peak of 0.8 m/s. The developed system achieved a position accuracy of 3.8 mm and a speed accuracy of 0.11 m/s. The analysis result demonstrated a time period of 66 minutes before the failure which is confirmed by significant signals from both imaging and contact sensors and is important for landslide early warning. A field implementation scheme in western China will be designed and realized in the near future. Numéro de notice : A2016-516 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.82.7.547 En ligne : http://dx.doi.org/10.14358/PERS.82.7.547 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81587
in Photogrammetric Engineering & Remote Sensing, PERS > vol 82 n° 7 (juillet 2016) . - pp 547 - 557[article]Evidence of postseismic deformation signal of the 2007 m8.5 Bengkulu earthquake and the 2012 m8.6 Indian ocean earthquake in southern Sumatra, Indonesia, based on GPS data / Satrio Muhammad Alif in Journal of applied geodesy, vol 10 n° 2 (June 2016)
[article]
Titre : Evidence of postseismic deformation signal of the 2007 m8.5 Bengkulu earthquake and the 2012 m8.6 Indian ocean earthquake in southern Sumatra, Indonesia, based on GPS data Type de document : Article/Communication Auteurs : Satrio Muhammad Alif, Auteur ; Irwan Meilano, Auteur ; Endra Gunawan, Auteur ; Joni Efendi, Auteur Année de publication : 2016 Article en page(s) : pp 103 - 108 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] analyse diachronique
[Termes IGN] coordonnées GPS
[Termes IGN] déformation de la croute terrestre
[Termes IGN] faille géologique
[Termes IGN] Sumatra
[Termes IGN] vitesseRésumé : (auteur) GPS data in southern Sumatra, Indonesia, indicate crustal deformation associated to subduction zone and inland fault of Great Sumatran Fault (GSF). We analyze these deformation characteristics using campaign and continuous GPS data available in southern Sumatra from 2006–2014. After removing the effect of GSF in southern Sumatra and coseismic displacements of 2007 Bengkulu and 2012 Indian Ocean earthquake, we find that GPS sites experienced northwest-ward direction. These GPS velocities correspond to postseismic deformation of the 2007 Bengkulu earthquake and the 2012 Indian Ocean earthquake. We analyze strain using these velocities, and we find that postseismic strains in southern Sumatra are in the range of 0.8–20 nanostrain. Numéro de notice : A2016-558 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1515/jag-2015-0019 En ligne : http://dx.doi.org/10.1515/jag-2015-0019 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81737
in Journal of applied geodesy > vol 10 n° 2 (June 2016) . - pp 103 - 108[article]Towards reliable velocities of permanent GNSS stations / Janusz Bogusz in Reports on geodesy and geoinformatics, vol 100 (May 2016)PermalinkClarifying the ambiguities: Examining the interoperability of precise point positioning products / Garrett Seepersad in GPS world, vol 27 n° 3 (March 2016)PermalinkCouplage de mesures GNSS et inertielles pour de la navigation pédestre dans les bâtiments / Sylvain Chable in XYZ, n° 146 (mars - mai 2016)PermalinkMIDAS robust trend estimator for accurate GPS station velocities without step detection / Geoffrey Blewitt in Journal of geophysical research : Solid Earth, vol 121 n° 3 (March 2016)PermalinkReal time monitoring ground motion using GPS with real time corrections / R. Tu in Survey review, vol 48 n° 347 (March 2016)PermalinkA comprehensive cartographic approach to evacuation map creation for Hurricane Ike in Galveston County, Texas / Yin-Hsuen Chen in Cartography and Geographic Information Science, Vol 43 n° 1 (January 2016)PermalinkCorrection de nuages de points lidar embarqué sur véhicule pour la reconstruction d’environnement 3D vaste / Pierre Merriaux (2016)PermalinkPermalinkSpatio-temporal traffic video data archiving and retrieval system / Hang Yue in Geoinformatica, vol 20 n° 1 (January - March 2016)PermalinkDevelopment and operational analysis of an all-fiber coherent doppler Lidar system for wind sensing and aerosol profiling / Sameh Abdelazim in IEEE Transactions on geoscience and remote sensing, vol 53 n° 12 (December 2015)PermalinkMapping slope movements in Alpine environments using TerraSAR-X interferometric methods / Chloé Barboux in ISPRS Journal of photogrammetry and remote sensing, vol 109 (November 2015)PermalinkMulti-method monitoring of Glacier d’Argentière dynamics / Lionel Benoit in Annals of Glaciology, vol 56 n° 70 (October 2015)PermalinkPlanning unobstructed paths in traffic-aware spatial networks / Shuo Shang in Geoinformatica, vol 19 n° 4 (October - December 2015)PermalinkCalculation of position and velocity of GLONASS satellite based on analytical theory of motion / W. Goral in Artificial satellites, vol 50 n° 3 (September 2015)PermalinkThe full-scale avalanche test-site at Lautaret Pass (French Alps) / Emmanuel Thibert in Cold regions science and technology, vol 115 (July 2015)PermalinkPermalinkNetwork-based estimation of time-dependent noise in GPS position time series / Ksenia Dimitrieva in Journal of geodesy, vol 89 n° 6 (June 2015)PermalinkKALREF, a Kalman filter and time series approach to the International Terrestrial Reference Frame realization / Xiaoping Wu in Journal of geophysical research : Solid Earth, vol 120 n° 5 (May 2015)PermalinkHow does a GNSS receiver estimate velocity? / Salvatore Gaglione in Inside GNSS, vol 10 n° 2 (March - April 2015)PermalinkReal-time high-precision earthquake monitoring using single-frequency GPS receivers / Min Li in GPS solutions, vol 19 n° 1 (January 2015)Permalink