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Understanding collective human movement dynamics during large-scale events using big geosocial data analytics / Junchuan Fan in Computers, Environment and Urban Systems, vol 87 (May 2021)
[article]
Titre : Understanding collective human movement dynamics during large-scale events using big geosocial data analytics Type de document : Article/Communication Auteurs : Junchuan Fan, Auteur ; Kathleen Stewart, Auteur Année de publication : 2021 Article en page(s) : n° 101605 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] collecte de données
[Termes IGN] données GPS
[Termes IGN] données issues des réseaux sociaux
[Termes IGN] données localisées des bénévoles
[Termes IGN] données massives
[Termes IGN] dynamique spatiale
[Termes IGN] échantillonnage de données
[Termes IGN] éclipse solaire
[Termes IGN] estimation par noyau
[Termes IGN] Etats-Unis
[Termes IGN] événement
[Termes IGN] géolocalisation
[Termes IGN] migration humaine
[Termes IGN] mobilité territoriale
[Termes IGN] téléphonie mobileRésumé : (auteur) Conventional approaches for modeling human mobility pattern often focus on human activity and movement dynamics in their regular daily lives and cannot capture changes in human movement dynamics in response to large-scale events. With the rapid advancement of information and communication technologies, many researchers have adopted alternative data sources (e.g., cell phone records, GPS trajectory data) from private data vendors to study human movement dynamics in response to large-scale natural or societal events. Big geosocial data such as georeferenced tweets are publicly available and dynamically evolving as real-world events are happening, making it more likely to capture the real-time sentiments and responses of populations. However, precisely-geolocated geosocial data is scarce and biased toward urban population centers. In this research, we developed a big geosocial data analytical framework for extracting human movement dynamics in response to large-scale events from publicly available georeferenced tweets. The framework includes a two-stage data collection module that collects data in a more targeted fashion in order to mitigate the data scarcity issue of georeferenced tweets; in addition, a variable bandwidth kernel density estimation(VB-KDE) approach was adopted to fuse georeference information at different spatial scales, further augmenting the signals of human movement dynamics contained in georeferenced tweets. To correct for the sampling bias of georeferenced tweets, we adjusted the number of tweets for different spatial units (e.g., county, state) by population. To demonstrate the performance of the proposed analytic framework, we chose an astronomical event that occurred nationwide across the United States, i.e., the 2017 Great American Eclipse, as an example event and studied the human movement dynamics in response to this event. However, this analytic framework can easily be applied to other types of large-scale events such as hurricanes or earthquakes. Numéro de notice : A2021-275 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/SOCIETE NUMERIQUE Nature : Article DOI : 10.1016/j.compenvurbsys.2021.101605 Date de publication en ligne : 05/02/2021 En ligne : https://doi.org/10.1016/j.compenvurbsys.2021.101605 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97358
in Computers, Environment and Urban Systems > vol 87 (May 2021) . - n° 101605[article]Integer phase clock method with single-satellite ambiguity fixing and its application in LEO satellite orbit determination / Kai Shao in Acta Geodaetica et Cartographica Sinica, vol 50 n° 4 ([20/04/2021])
[article]
Titre : Integer phase clock method with single-satellite ambiguity fixing and its application in LEO satellite orbit determination Type de document : Article/Communication Auteurs : Kai Shao, Auteur ; Bin Yi, Auteur ; Houzhe Zhang, Auteur ; Defeng Gu, Auteur Année de publication : 2021 Article en page(s) : pp 487 - 495 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] bande K
[Termes IGN] orbite basse
[Termes IGN] orbitographie
[Termes IGN] phase
[Termes IGN] phase GNSS
[Termes IGN] résolution d'ambiguïtéRésumé : (auteur) Fixing single-satellite GPS carrier phase ambiguity could significantly improve the orbit accuracy of low earth orbit (LEO) satellite. Currently, the CNES/CLS, Wuhan University and CODE have published GPS integer phase clock products applied to single-satellite ambiguity fixing. In this paper, the integer phase clock method is used for single-satellite ambiguity fixing, and it is applied to the precise orbit determination of LEO satellite. Then, the application performances of integer phase clock products provided by different agencies in single-satellite ambiguity fixing and LEO satellite orbit determination are compared and analyzed. For GRACE-FO formation satellites, about 94% ambiguities could be fixed based on different products provided by the three agencies. Orbit solutions generated using the products from the three agencies can achieve an RMS of around 0.9 cm checked by satellite laser ranging data. Compared with ambiguity-float orbit solutions, the accuracy of absolute orbit determination with single-satellite ambiguity fixing is improved by about 30%. After fixing single-satellite ambiguities using the different products provided by CNES/CLS, WHU and CODE, respectively, the RMS of K-band ranging validation residuals for relative orbit solutions are reduced from 5.7, 5.4 and 5.3 mm to 2.1、 2.0 and 1.5 mm, respectively. The results show that the integer phase clock products provided by different agencies have similar performances in the single-satellite ambiguity fixing and orbit determination of GRACE-FO satellite. Numéro de notice : A2021-310 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.11947/j.AGCS.2021.20200302 Date de publication en ligne : 20/04/2021 En ligne : https://doi.org/10.11947/j.AGCS.2021.20200302 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97755
in Acta Geodaetica et Cartographica Sinica > vol 50 n° 4 [20/04/2021] . - pp 487 - 495[article]Automatic atmospheric correction for shortwave hyperspectral remote sensing data using a time-dependent deep neural network / Jian Sun in ISPRS Journal of photogrammetry and remote sensing, vol 174 (April 2021)
[article]
Titre : Automatic atmospheric correction for shortwave hyperspectral remote sensing data using a time-dependent deep neural network Type de document : Article/Communication Auteurs : Jian Sun, Auteur ; Fangcao Xu, Auteur ; Guido Cervone, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 117 - 131 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] apprentissage profond
[Termes IGN] classification par réseau neuronal convolutif
[Termes IGN] correction atmosphérique
[Termes IGN] détection de cible
[Termes IGN] image hyperspectrale
[Termes IGN] modèle de transfert radiatif
[Termes IGN] rayonnement solaire
[Termes IGN] réflectivitéRésumé : (auteur) Atmospheric correction is an essential step in hyperspectral imaging and target detection from spectrometer remote sensing data. State-of-the-art atmospheric correction approaches either require extensive filed experiments or prior knowledge of atmospheric characteristics to improve the predicted accuracy, which are computational expensive and unsuitable for real time application. To take full advantages of remote sensing observation in quickly and reliably acquiring data for a large area, an automatic and efficient processing tool is required for atmospheric correction. In this paper, we propose a time-dependent neural network for automatic atmospheric correction and target detection using multi-scan hyperspectral data under different elevation angles. In addition to the total radiance, the collection day and time are also incorporated to improve the time-dependency of the network and represent the seasonal and diurnal characteristics of atmosphere and solar radiation. Results show that the proposed network has the capacity to accurately provide atmospheric characteristics and estimate precise reflectivity spectra with 95,72% averaged accuracy for different materials, including vegetation, sea ice, and ocean. Additional experiments are designed to investigate the network’s temporal dependency and performance on missing data. The error analysis confirms that our proposed network is capable of estimating atmospheric characteristics under both seasonally and diurnally varying environments and handling the influence of missing data. Both the predicted results and error analysis are promising and demonstrate that our network has the ability of providing accurate atmospheric correction and target detection in real time. Numéro de notice : A2021-208 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2021.02.007 Date de publication en ligne : 24/02/2021 En ligne : https://doi.org/10.1016/j.isprsjprs.2021.02.007 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97186
in ISPRS Journal of photogrammetry and remote sensing > vol 174 (April 2021) . - pp 117 - 131[article]Réservation
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[article]
Titre : POD of small LEO satellites based on precise real-time MADOCA and SBAS-aided PPP corrections Type de document : Article/Communication Auteurs : Amir Allahvirdi-Zadeh, Auteur ; Kan Wang, Auteur ; Ahmed El-Mowafy, Auteur Année de publication : 2021 Article en page(s) : 14 p. Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Techniques orbitales
[Termes IGN] données GNSS
[Termes IGN] horloge du satellite
[Termes IGN] orbite basse
[Termes IGN] orbitographie par GNSS
[Termes IGN] positionnement ponctuel précis
[Termes IGN] temps réelRésumé : (Auteur) For real-time precise orbit determination (POD) of low earth orbit (LEO) satellites, high-accuracy global navigation satellite system (GNSS) orbit and clock products are necessary in real time. Recently, the Japanese multi-GNSS advanced demonstration of orbit and clock analysis precise point positioning (PPP) service and the new generation of the Australian/New Zealand satellite-based augmentation system (SBAS)-aided PPP service provide free and precise GNSS products that are directly broadcast through the navigation and geostationary earth orbit satellites, respectively. With the high quality of both products shown in this study, a 3D accuracy of centimeters can be achieved in the post-processing mode for the reduced-dynamic orbits of small LEO satellites having a duty cycle down to 40% and at sub-dm to dm level for the kinematic orbits. The results show a promising future for high-accuracy real-time POD onboard LEO satellites benefiting from the precise free-of-charge PPP corrections broadcast by navigation systems or SBAS. Numéro de notice : A2021-091 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10291-020-01078-8 Date de publication en ligne : 11/01/2021 En ligne : https://doi.org/10.1007/s10291-020-01078-8 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96880
in GPS solutions > vol 25 n° 2 (April 2021) . - 14 p.[article]
Titre : Assessment of renewable energy resources with remote sensing Type de document : Monographie Auteurs : Fernando Ramos Martins, Éditeur scientifique Editeur : Bâle [Suisse] : Multidisciplinary Digital Publishing Institute MDPI Année de publication : 2021 Importance : 244 p. Format : 16 x 23 cm ISBN/ISSN/EAN : 978-3-0365-0481-0 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] apprentissage automatique
[Termes IGN] climat
[Termes IGN] détection des nuages
[Termes IGN] données lidar
[Termes IGN] énergie éolienne
[Termes IGN] énergie géothermique
[Termes IGN] énergie renouvelable
[Termes IGN] énergie solaire
[Termes IGN] Extreme Gradient Machine
[Termes IGN] hydroélectricité
[Termes IGN] image GOES
[Termes IGN] Matlab
[Termes IGN] prévision météorologique
[Termes IGN] rayonnement solaire
[Termes IGN] réseau neuronal artificiel
[Termes IGN] semis de pointsRésumé : (éditeur) The book “Assessment of Renewable Energy Resources with Remote Sensing" focuses on disseminating scientific knowledge and technological developments for the assessment and forecasting of renewable energy resources using remote sensing techniques. The eleven papers inside the book provide an overview of remote sensing applications on hydro, solar, wind and geothermal energy resources and their major goal is to provide state of art knowledge to contribute with the renewable energy resource deployment, especially in regions where energy demand is rapidly expanding. Renewable energy resources have an intrinsic relationship with local environmental features and the regional climate. Even small and fast environment and/or climate changes can cause significant variability in power generation at different time and space scales. Methodologies based on remote sensing are the primary source of information for the development of numerical models that aim to support the planning and operation of an electric system with a substantial contribution of intermittent energy sources. In addition, reliable data and knowledge on renewable energy resource assessment are fundamental to ensure sustainable expansion considering environmental, financial and energetic security. Note de contenu : 1- Enhancement of cloudless skies frequency over a large tropical reservoir in Brazil
2- On the land-sea contrast in the surface solar radiation (SSR) in the Baltic region
3- Real-time automatic cloud detection using a low-cost sky camera
4- Attenuation factor estimation of direct normal irradiance combining sky camera images and mathematical models in an inter-tropical area
5- Multistep-ahead solar radiation forecasting scheme based on the light gradient boosting machine: A case study of Jeju Island
6- Modified search strategies assisted crossover whale optimization algorithm with selection operator for parameter extraction of solar photovoltaic models
7- Industry experience of developing day-ahead photovoltaic plant forecasting system based on machine learning
8- The global wind resource observed by scatterometer
9- Coastal wind measurements using a single scanning LiDAR
10- Characterizing geological heterogeneities for geothermal purposes through combined geophysical prospecting methods
11- A computational workflow for generating a voxel-based design approach based on subtractive shading envelopes and attribute information of point cloud dataNuméro de notice : 28653 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Recueil / ouvrage collectif DOI : 10.3390/books978-3-0365-0481-0 En ligne : https://doi.org/10.3390/books978-3-0365-0481-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99795 Determination of the lunar body tide from global laser altimetry data / Robin N. Thor in Journal of geodesy, vol 95 n° 1 (January 2021)PermalinkProjet ROYMAGE : une horloge optique transportable pour des applications géodésiques et géophysiques [diaporama] / Guillaume Lion (2021)PermalinkROYMAGE Project: a transportable clock for geodetic and geophysical applications / Guillaume Lion (2021)PermalinkSBAS-aided GPS positioning with an extended ionosphere map at the boundaries of WAAS service area / Mingyu Kim in Remote sensing, vol 13 n° 1 (January-1 2021)PermalinkReference system origin and scale realization within the future GNSS constellation “Kepler” / Susanne Glaser in Journal of geodesy, vol 94 n° 12 (December 2020)PermalinkIntegrated processing of ground- and space-based GPS observations: improving GPS satellite orbits observed with sparse ground networks / Wen Huang in Journal of geodesy, vol 94 n° 10 (October 2020)PermalinkSensor tasking for search and catalog maintenance of geosynchronous space objects / Han Cai in Acta Astronautica, vol 175 (October 2020)PermalinkCrater detection and registration of planetary images through marked point processes, multiscale decomposition, and region-based analysis / David Solarna in IEEE Transactions on geoscience and remote sensing, vol 58 n° 9 (September 2020)PermalinkNovel communication channel model for signal propagation and loss through layered earth / David O. LeVan in IEEE Transactions on geoscience and remote sensing, vol 58 n° 8 (August 2020)PermalinkOrbit and clock analysis of BDS-3 satellites using inter-satellite link observations / Xin Xie in Journal of geodesy, vol 94 n° 7 (July 2020)Permalink