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The soil moisture active passive validation experiment 2012 (SMAPVEX12): Prelaunch calibration and validation of the SMAP Soil moisture algorithms / Heather McNairn in IEEE Transactions on geoscience and remote sensing, vol 53 n° 5 (mai 2015)
[article]
Titre : The soil moisture active passive validation experiment 2012 (SMAPVEX12): Prelaunch calibration and validation of the SMAP Soil moisture algorithms Type de document : Article/Communication Auteurs : Heather McNairn, Auteur ; Thomas J. Jackson, Auteur ; Grant Wiseman, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 2784 - 2801 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] analyse de données
[Termes IGN] bande L
[Termes IGN] étalonnage
[Termes IGN] étalonnage de capteur (imagerie)
[Termes IGN] humidité du sol
[Termes IGN] image aérienne
[Termes IGN] image radar
[Termes IGN] Soil Moisture Active Passive
[Termes IGN] télédétection en hyperfréquence
[Termes IGN] test de performanceRésumé : (auteur) The National Aeronautics and Space Administration (NASA) Soil Moisture Active Passive (SMAP) satellite is scheduled for launch in January 2015. In order to develop robust soil moisture retrieval algorithms that fully exploit the unique capabilities of SMAP, algorithm developers had identified a need for long-duration combined active and passive L-band microwave observations. In response to this need, a joint Canada-U.S. field experiment (SMAPVEX12) was conducted in Manitoba (Canada) over a six-week period in 2012. Several times per week, NASA flew two aircraft carrying instruments that could simulate the observations the SMAP satellite would provide. Ground crews collected soil moisture data, crop measurements, and biomass samples in support of this campaign. The objective of SMAPVEX12 was to support the development, enhancement, and testing of SMAP soil moisture retrieval algorithms. This paper details the airborne and field data collection as well as data calibration and analysis. Early results from the SMAP active radar retrieval methods are presented and demonstrate that relative and absolute soil moisture can be delivered by this approach. Passive active L-band sensor (PALS) antenna temperatures and reflectivity, as well as backscatter, closely follow dry down and wetting events observed during SMAPVEX12. The SMAPVEX12 experiment was highly successful in achieving its objectives and provides a unique and valuable data set that will advance algorithm development. Numéro de notice : A2015-631 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2014.2364913 En ligne : https://doi.org/10.1109/TGRS.2014.2364913 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=78119
in IEEE Transactions on geoscience and remote sensing > vol 53 n° 5 (mai 2015) . - pp 2784 - 2801[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 065-2015051 RAB Revue Centre de documentation En réserve L003 Disponible A Galileo IOV assessment: measurement and position domain / Ciro Gioia in GPS solutions, vol 19 n° 2 (April 2015)
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Titre : A Galileo IOV assessment: measurement and position domain Type de document : Article/Communication Auteurs : Ciro Gioia, Auteur ; Daniele Borio, Auteur ; Antonio Angrisano, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 187 - 199 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] GIOVE (satellite)
[Termes IGN] mesurage de pseudo-distance
[Termes IGN] test de performanceRésumé : (auteur) The European GNSS, Galileo, is currently in its in-orbit validation (IOV) phase where four satellites are finally available for computing the user position. In this phase, the analysis of the measurements and position velocity and time (PVT) obtained from the IOV satellites can provide insight into the potentialities of the Galileo system. A methodology is suggested for the analysis of the Galileo IOV pseudorange and pseudorange rates collected from the E1 and E5 frequencies. Several days of data were collected and processed to determine figures of merit such as root mean square and maximum errors of the Galileo observables. From the analysis, it emerges that Galileo is able to achieve better accuracy than GPS. A thorough analysis of the PVT performance is also carried out using broadcast ephemerides. Galileo and GPS PVTs are compared under similar geometry conditions showing the potential of the Galileo system. Numéro de notice : A2015-206 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-014-0379-3 En ligne : https://doi.org/10.1007/s10291-014-0379-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76020
in GPS solutions > vol 19 n° 2 (April 2015) . - pp 187 - 199[article]GMOBench: Benchmarking generic moving objects / Jianqiu Xu in Geoinformatica, vol 19 n° 2 (April - June 2015)
[article]
Titre : GMOBench: Benchmarking generic moving objects Type de document : Article/Communication Auteurs : Jianqiu Xu, Auteur ; Ralf Hartmut Güting, Auteur ; Xiaolin Qin, Auteur Année de publication : 2015 Article en page(s) : pp 227 - 276 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] arbre-R
[Termes IGN] base de données orientée objet
[Termes IGN] implémentation (informatique)
[Termes IGN] index spatial
[Termes IGN] mobilité humaine
[Termes IGN] mobilité urbaine
[Termes IGN] objet mobile
[Termes IGN] point de repère
[Termes IGN] requête spatiale
[Termes IGN] test de performanceRésumé : (auteur) In real world scenarios, people’s movement include several environments rather than one, for example, road network, pavement areas and indoor. This imposes a new challenge for moving objects database that the complete trip needs to be managed by a database system. In the meantime, novel queries regarding different transportation modes should also be supported. Since existing methods are limited to trips in a single environment and do not support queries on moving objects with different transportation modes, new technologies are essentially needed in a database system. In this paper, we introduce a benchmark called GMOBench that aims to evaluate the performance of a database system managing moving objects in different environments. GMOBench is settled in a realistic scenario and is comprised of three components: (1) a data generator with the capability of creating a scalable set of trips representing the complete movement of humans (both indoor and outdoor); (2) a set of carefully designed and benchmark queries; (3) Mode-RTree, an index structure for managing generic moving objects. The generator defines some parameters so that users can control the characteristics of results. We create the benchmark data in such a way that the dataset can mirror important characteristics and real world distributions of human mobility. Efficient access methods and optimization techniques are developed for query processing. In particular, we propose an index structure called Mode-RTree to manage moving objects in different environments. By employing the proposed index, the cost of benchmark queries is greatly reduced. GMOBench is implemented in a real database system to have a practical result. We perform an extensive experimental study on comprehensive datasets to evaluate the performance. The results show that by using the Mode-RTree we achieve significant performance improvement over the baseline method, demonstrating the effectiveness and efficiency of our approaches. Numéro de notice : A2015-488 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s10707-014-0211-9 Date de publication en ligne : 26/06/2014 En ligne : https://doi.org/10.1007/s10707-014-0211-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77281
in Geoinformatica > vol 19 n° 2 (April - June 2015) . - pp 227 - 276[article]Performance analysis of radial basis function networks and multi-layer perceptron networks in modeling urban change: a case study / Hossein Shafizadeh-Moghadam in International journal of geographical information science IJGIS, vol 29 n° 4 (April 2015)
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Titre : Performance analysis of radial basis function networks and multi-layer perceptron networks in modeling urban change: a case study Type de document : Article/Communication Auteurs : Hossein Shafizadeh-Moghadam, Auteur ; Julian Hagenauer, Auteur ; Manuchehr Farajzadeh, Auteur ; Marco Helbich, Auteur Année de publication : 2015 Article en page(s) : pp 606 - 623 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] apprentissage automatique
[Termes IGN] Bombay
[Termes IGN] croissance urbaine
[Termes IGN] fonction de base radiale
[Termes IGN] milieu urbain
[Termes IGN] modèle de simulation
[Termes IGN] Perceptron multicouche
[Termes IGN] performance
[Termes IGN] test de performance
[Termes IGN] urbanisationRésumé : (Auteur) The majority of cities are rapidly growing. This makes the monitoring and modeling of urban change’s spatial patterns critical to urban planners, decision makers, and environment protection activists. Although a wide range of methods exists for modeling and simulating urban growth, machine learning (ML) techniques have received less attention despite their potential for producing highly accurate predictions of future urban extents. The aim of this study is to investigate two ML techniques, namely radial basis function network (RBFN) and multi-layer perceptron (MLP) networks, for modeling urban change. By predicting urban change for 2010, the models’ performance is evaluated by comparing results with a reference map and by using a set of pertinent statistical measures, such as average spatial distance deviation and figure of merit. The application of these techniques employs the case study area of Mumbai, India. The results show that both models, which were tested using the same explanatory variables, produced promising results in terms of predicting the size and extent of future urban areas. Although a close match between RBFN and MLP is observed, RBFN demonstrates higher spatial accuracy of prediction. Accordingly, RBFN was utilized to simulate urban change for 2020 and 2030. Overall, the study provides evidence that RBFN is a robust and efficient ML technique and can therefore be recommended for land use change modeling. Numéro de notice : A2015-589 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2014.993989 En ligne : http://www.tandfonline.com/doi/full/10.1080/13658816.2014.993989 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77875
in International journal of geographical information science IJGIS > vol 29 n° 4 (April 2015) . - pp 606 - 623[article]Forming a global monitoring mechanism and a spatiotemporal performance model for geospatial services / Jizhe Xia in International journal of geographical information science IJGIS, vol 29 n° 3 (March 2015)
[article]
Titre : Forming a global monitoring mechanism and a spatiotemporal performance model for geospatial services Type de document : Article/Communication Auteurs : Jizhe Xia, Auteur ; Chaowei Yang, Auteur ; K. Liu, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 375 - 396 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web
[Termes IGN] architecture orientée services
[Termes IGN] données massives
[Termes IGN] évaluation
[Termes IGN] informatique en nuage
[Termes IGN] infrastructure mondiale des données localisées
[Termes IGN] modèle conceptuel de données spatio-temporelles
[Termes IGN] service web géographique
[Termes IGN] test de performanceRésumé : (Auteur) Geographic information service (GIService) has become popular in the last decade to develop applications for addressing global challenges. Performance is one of the most important criteria to help users select distributed online GIService for developing geospatial applications including natural hazards and emergency responses. However, performance accuracy is limited by the single-location-based evaluation mechanism while service performance is dynamic in space and time between end-users and services. We propose a spatiotemporal performance evaluation mechanism to improve the accuracy. Specially, a cloud and volunteer computing mechanism is proposed to collect performance information of globally distributed GIServices. A global spatiotemporal performance model is designed to integrate spatiotemporal dynamics for better performance evaluation for users from different regions at different times. This model is tested to support GIService selection in global spatial data infrastructures (SDIs). The experiment confirms that the proposed model provides more accurate evaluations for global users and better supports geospatial resource utilizations in SDIs than previous mechanisms. The methodology can be adopted to improve the services of other regional and global distributed operational systems. Numéro de notice : A2015-583 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2014.968783 En ligne : http://www.tandfonline.com/doi/full/10.1080/13658816.2014.968783 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77869
in International journal of geographical information science IJGIS > vol 29 n° 3 (March 2015) . - pp 375 - 396[article]Gravity field processing with enhanced numerical precision for LL-SST missions / Ilias Daras in Journal of geodesy, vol 89 n° 2 (February 2015)PermalinkBenchmarking framework for SAR despeckling / Gerardo Di Martino in IEEE Transactions on geoscience and remote sensing, vol 52 n° 3 (March 2014)PermalinkComparaison des dendromètres Vertex III et Trupulse 200b pour la mesure de la hauteur totale des arbres / Sylvain Gaudin in Revue forestière française, vol 66 n° 2 (mars - avril 2014)PermalinkA PET project from Finland / Sarang Thrombe in GPS world, vol 25 n° 3 (March 2014)PermalinkLe positionnement par satellite : les nouveaux récepteurs améliorent-ils les performances sous couvert forestier ? / Alain Munoz in Rendez-vous techniques, n° 43 (Mars 2014)PermalinkMultiple-entity based classification of airborne laser scanning data in urban areas / S. Xu in ISPRS Journal of photogrammetry and remote sensing, vol 88 (February 2014)PermalinkPermalinkAnalyses aux limites des scanners laser terrestres : Alter 2, auscultation via scanner laser terrestre. 1ère partie / Vincent Barras in XYZ, n° 137 (décembre 2013 - février 2014)PermalinkPerformance evaluation of USTEC product for single-frequency precise point positioning / Mahmoud Abd-El-Rahman in Geomatica, vol 67 n° 4 (December 2013)PermalinkScanners laser terrestres en conditions réelles : Alter 2, auscultation via scanner laser terrestre. 2ème partie / Vincent Barras in XYZ, n° 137 (décembre 2013 - février 2014)Permalink