Centre de documentation
scientifique

Detecting and visualizing observation hot-spots in massive volunteer-contributed geographic data across spatial scales using GPU-accelerated kernel density estimation / Guiming Zhang in ISPRS International journal of geo-information, vol 11 n° 1 (January 2022)  

Public [article]  inISPRS International journal of geo-information > vol 11 n° 1 (January 2022) . - n° 55 Titre : Detecting and visualizing observation hot-spots in massive volunteer-contributed geographic data across spatial scales using GPU-accelerated kernel density estimation Type de document : Article/Communication Auteurs : Guiming Zhang, Auteur Année de publication : 2022 Article en page(s) : n° 55 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] données localisées des bénévoles [Termes IGN] données massives [Termes IGN] estimation par noyau [Termes IGN] exploration de données géographiques [Termes IGN] géovisualisation [Termes IGN] processeur graphique [Termes IGN] qualité des données [Termes IGN] réseau social [Termes IGN] tâche claire Résumé : (auteur) Volunteer-contributed geographic data (VGI) is an important source of geospatial big data that support research and applications. A major concern on VGI data quality is that the underlying observation processes are inherently biased. Detecting observation hot-spots thus helps better understand the bias. Enabled by the parallel kernel density estimation (KDE) computational tool that can run on multiple GPUs (graphics processing units), this study conducted point pattern analyses on tens of millions of iNaturalist observations to detect and visualize volunteers’ observation hot-spots across spatial scales. It was achieved by setting varying KDE bandwidths in accordance with the spatial scales at which hot-spots are to be detected. The succession of estimated density surfaces were then rendered at a sequence of map scales for visual detection of hot-spots. This study offers an effective geovisualization scheme for hierarchically detecting hot-spots in massive VGI datasets, which is useful for understanding the pattern-shaping drivers that operate at multiple spatial scales. This research exemplifies a computational tool that is supported by high-performance computing and capable of efficiently detecting and visualizing multi-scale hot-spots in geospatial big data and contributes to expanding the toolbox for geospatial big data analytics. Numéro de notice : A2022-091 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi11010055 Date de publication en ligne : 12/01/2022 En ligne : https://doi.org/10.3390/ijgi11010055 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99507 [article]

Motion blur disturbs – the influence of motion-blurred images in photogrammetry / T. Sieberth in Photogrammetric record, vol 29 n° 148 (December 2014 - February 2015)  

Public [article]  inPhotogrammetric record > vol 29 n° 148 (December 2014 - February 2015) . - pp 434 – 453 Titre : Motion blur disturbs – the influence of motion-blurred images in photogrammetry Type de document : Article/Communication Auteurs : T. Sieberth, Auteur ; R. Wackrow, Auteur ; Jim H. Chandler, Auteur Année de publication : 2014 Article en page(s) : pp 434 – 453 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] étalonnage de capteur (imagerie) [Termes IGN] flou [Termes IGN] image à haute résolution [Termes IGN] tâche claire [Termes IGN] traitement d'image Résumé : (Auteur) Unmanned aerial vehicles (UAVs) have become an interesting and active research topic for photogrammetry. Current research is based on images acquired by UAVs which have a high ground resolution and good spectral resolution due to low flight altitudes combined with a high-resolution camera. One of the main problems preventing full automation of data processing of UAV imagery is the unknown degradation effect of blur caused by camera movement during image acquisition. The purpose of this paper is to analyse the influence of blur on photogrammetric image processing. Images with precisely known motion blur were produced to determine the effect. It was found that even small blurs affect normal photogrammetric processes significantly. Although operator intervention might be time consuming, it can ensure that the results are still of acceptable accuracy. Numéro de notice : A2014-649 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12082 Date de publication en ligne : 16/12/2014 En ligne : https://doi.org/10.1111/phor.12082 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75095 [article]

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106-2014041	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Geolocation and stereo height estimation using TerraSAR-X spotlight image data / K. Eldhuset in IEEE Transactions on geoscience and remote sensing, vol 49 n° 10 Tome 1 (October 2011)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 49 n° 10 Tome 1 (October 2011) . - pp 3574 - 3581 Titre : Geolocation and stereo height estimation using TerraSAR-X spotlight image data Type de document : Article/Communication Auteurs : K. Eldhuset, Auteur ; Dan Johan Weydahl, Auteur Année de publication : 2011 Article en page(s) : pp 3574 - 3581 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] coin réflecteur [Termes IGN] géoréférencement direct [Termes IGN] hauteur du bâti [Termes IGN] image TerraSAR-X [Termes IGN] précision du positionnement [Termes IGN] tâche claire Résumé : (Auteur) We have studied the geographic position of several high-resolution spotlight TSX images by investigating the location of deployed radar corner reflectors. Results show that the geolocation accuracy is better than the resolution cell in both azimuth and range directions. The same corner reflectors as well as distinct points on buildings are used to estimate the absolute height from stereo viewing spotlight TSX images to within a few decimeters accuracy. Numéro de notice : A2011-426 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2011.2160951 Date de publication en ligne : 29/07/2011 En ligne : https://doi.org/10.1109/TGRS.2011.2160951 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31205 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-201110A1	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Computational method for the point cluster analysis on networks / K. Sugihara in Geoinformatica, vol 15 n° 1 (January 2011)  

Public [article]  inGeoinformatica > vol 15 n° 1 (January 2011) . - pp 167 - 189 Titre : Computational method for the point cluster analysis on networks Type de document : Article/Communication Auteurs : K. Sugihara, Auteur ; Atsuyuki Okabe, Auteur ; T. Satoh, Auteur Année de publication : 2011 Article en page(s) : pp 167 - 189 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] analyse de groupement [Termes IGN] approche hiérarchique [Termes IGN] distance euclidienne [Termes IGN] réseau [Termes IGN] tâche claire Résumé : (Auteur) We present a general framework of hierarchical methods for point cluster analysis on networks, and then consider individual clustering procedures and their time complexities defined by typical variants of distances between clusters. The distances considered here are the closest-pair distance, the farthest-pair distance, the average distance, the median-pair distance and the radius distance. This paper will offer a menu for users to choose hierarchical clustering algorithms on networks from a time complexity point of view. Numéro de notice : A2011-032 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s10707-009-0092-5 Date de publication en ligne : 03/09/2009 En ligne : https://doi.org/10.1007/s10707-009-0092-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30813 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
057-2011011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

ASTER observations of thermal anomalies preceding the April 2003 eruption of Chikurachki volcano, Kurile Islands, Russia / D. Pieri in Remote sensing of environment, vol 99 n° 1-2 (15 November 2005)  

Public [article]  inRemote sensing of environment > vol 99 n° 1-2 (15 November 2005) . - pp 84 - 94 Titre : ASTER observations of thermal anomalies preceding the April 2003 eruption of Chikurachki volcano, Kurile Islands, Russia Type de document : Article/Communication Auteurs : D. Pieri, Auteur ; Michael Abrams, Auteur Année de publication : 2005 Article en page(s) : pp 84 - 94 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] anomalie thermique [Termes IGN] éruption volcanique [Termes IGN] image Terra-ASTER [Termes IGN] image thermique [Termes IGN] rayonnement infrarouge thermique [Termes IGN] risque naturel [Termes IGN] Russie [Termes IGN] surveillance géologique [Termes IGN] tâche claire Résumé : (Auteur) Chikurachki volcano (Nothern Kurile Islands Chain, Paramushir Island 50° 20'N, 155° 27'E; elevation 1816 m, stratovolcano) has been in a state of unrest for over twenty years. Its most recent eruption that began in April 2003 was preceded by an eruption between January May 2002. Thermal infrared images from the Japanese-United States' Advanced Spacebome Thermal Emission and Reflection Radiometer (ASTER-5 TIR channels, 8-12 um, 90 m/pixel, Noise Equivalent Delta Temperature [NET] 0.1-0.3 K, onboard the U.S. National Aeronautics and Space Administration's Terra polar-orbiting spacecraft) of a snow-covered Chikurachki Volcano taken in January 2003 show muted evidence of thermal activity. ASTER thermal infrared (TIR) images from February 2003, however, indicate warmer areas within the summit crater. Average whole-pixel temperatures of adjacent summit slopes are in the range of 250-252 K, while many summit-crater whole pixel temperatures are 2-6 K greater. A two component Planck solution for the warmer pixels yields a solution of 275-277 K for 10-15% of the Chikurachki summit crater and 285-295 K for 25-35% of a prominent "hotspot'* on its flank. An interpretation of this enhanced pre-eruption heat flow is the presence of surface melt water. The detection in ASTER data of such subtle precursory heat-flow enhancement, even retrospectively, raises important issues for remote monitoring of "dormant" snow-capped volcanoes, especially those that threaten nearby populations, like Mt. Rainier. Numéro de notice : A2005-442 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2005.06.012 En ligne : https://doi.org/10.1016/j.rse.2005.06.012 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27578 [article]

Airborne experimental measurements of the angular variations in surface temperature over urban areas: case study of Marseille (France) / J.P. Lagouarde in Remote sensing of environment, vol 93 n° 4 (15/12/2004)  

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Automated detection of thermal features of active volcanoes by means of infrared AVHRR records / N. Pergola in Remote sensing of environment, vol 93 n° 3 (15/11/2004)  

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Continental scale hotspot observations of Australia at sub-degree angular resolution from POLDER / F. Grant in International Journal of Remote Sensing IJRS, vol 25 n° 18 (September 2004)  

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Bidirectional reflectance of Earth targets: evaluation of analytical models using a large set of spaceborne measurements with emphasis on the Hot Spot / F. Maignan in Remote sensing of environment, vol 90 n° 2 (30/03/2004)  

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Airborne measurement of hot spot reflectance signatures / F. Camacho-De Coca in Remote sensing of environment, vol 90 n° 1 (15/03/2004)  

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Effets radiométriques en milieu urbain à grande échelle et correction des ombres / Gilles Martinoty in Géomatique expert, n° 32 (01/03/2004)

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A comparison of BRDF models for the normalization of satellite optical data to a standard sun-target-sensor geometry / R. Latifovic in IEEE Transactions on geoscience and remote sensing, vol 41 n° 8 (August 2003)  

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Geodynamics / D. Turcotte (2002)

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Observing our environment from space / G. Begni (2002)

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