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Titre : Lidar data classification using hierarchical K-means clustering Type de document : Article/Communication Auteurs : Frédéric Bretar, Auteur ; Nicolas David , Auteur ; Nesrine Chehata , Auteur Editeur : International Society for Photogrammetry and Remote Sensing ISPRS Année de publication : 2008 Collection : International Archives of Photogrammetry and Remote Sensing, ISSN 0252-8231 num. 37-B3 Conférence : ISPRS 2008, 21st ISPRS world congress 03/07/2008 11/07/2008 Pékin Chine OA ISPRS Archives Importance : pp 325 - 330 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] analyse de groupement
[Termes IGN] classification ascendante hiérarchique
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] filtrage de points
[Termes IGN] modèle numérique de terrain
[Termes IGN] pente
[Termes IGN] semis de pointsRésumé : (Auteur) This paper deals with lidar point cloud filtering and classification for modelling the Terrain and more generally for scene segmentation. In this study, we propose to use the well-known K-means clustering algorithm that filters and segments (point cloud) data. The K-means clustering is well adapted to lidar data processing, since different feature attributes can be used depending on the desired classes. Attributes may be geometric or textural when processing only 3D-point cloud but also spectral in case of joint use of optical images and lidar data. The algorithm is based on a fixed neighbourhood size that can deal with steep relief covered by dense vegetation, mountainous area and terrains which present micro-relieves. The novelty of our algorithm consists in providing a hierarchical splitting clustering to extract ground points. The number of cluster splits is used to qualify automatically the classification reliability. This point is rarely treated in previous works. Moreover landscape predictors such as slope map are used to locally refine the classification. Finally, the methodology is extended to a multi-scale framework. The hierarchical clustering is processed from coarse DTM resolution to finer one. This implementation improves the algorithm robustness and ensures reliable ground estimation. Quantitative and qualitative results are presented on the ISPRS data set. Numéro de notice : 10664 Affiliation des auteurs : MATIS (1993-2011) Thématique : IMAGERIE Nature : Communication DOI : sans En ligne : https://www.isprs.org/proceedings/XXXVII/congress/3b_pdf/65.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=64215 Documents numériques
en open access
10664_isprs_2008_chehata.pdfAdobe Acrobat PDF Supporting the process of exploring and interpreting space-time multivariate patterns: the visual inquiry toolkit / J. Chen in Cartography and Geographic Information Science, vol 35 n° 1 (January 2008)
[article]
Titre : Supporting the process of exploring and interpreting space-time multivariate patterns: the visual inquiry toolkit Type de document : Article/Communication Auteurs : J. Chen, Auteur ; Alan M. MacEachren, Auteur ; D. Guo, Auteur Année de publication : 2008 Article en page(s) : pp 33 - 50 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique
[Termes IGN] analyse de groupement
[Termes IGN] analyse visuelle
[Termes IGN] données spatiotemporelles
[Termes IGN] mise à l'échelle
[Termes IGN] reconnaissance de formes
[Termes IGN] visualisationRésumé : (Auteur) While many data sets carry geographic and temporal references, our ability to analyze these datasets lags behind our ability to collect them because of the challenges posed by both data complexity and tool scalability issues. This study develops a visual analytics approach that leverages human expertise with visual, computational, and cartographic methods to support the application of visual analytics to relatively large spatio-temporal, multivariate data sets. We develop and apply a variety of methods for data clustering, pattern searching, information visualization, and synthesis. By combining both human and machine strengths, this approach has a better chance to discover novel, relevant, and potentially useful information that is difficult to detect by any of the methods used in isolation. We demonstrate the effectiveness of the approach by applying the Visual Inquiry Toolkit we developed to analyze a data set containing geographically referenced, time-varying and multivariate data for U.S. technology industries. Copyright CaGISociety Numéro de notice : A2008-060 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1559/152304008783475689 En ligne : https://doi.org/10.1559/152304008783475689 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29055
in Cartography and Geographic Information Science > vol 35 n° 1 (January 2008) . - pp 33 - 50[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 032-08011 RAB Revue Centre de documentation En réserve L003 Disponible Regenerating boreal forest structure estimation using SPOT-5 pan-sharpened imagery / A.L. Wunderle in International Journal of Remote Sensing IJRS, vol 28 n°19-20 (October 2007)
[article]
Titre : Regenerating boreal forest structure estimation using SPOT-5 pan-sharpened imagery Type de document : Article/Communication Auteurs : A.L. Wunderle, Auteur ; Steven E. Franklin, Auteur ; X.G. Guo, Auteur Année de publication : 2007 Article en page(s) : pp 4351 - 4364 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] Alberta (Canada)
[Termes IGN] analyse en composantes principales
[Termes IGN] complexité
[Termes IGN] forêt boréale
[Termes IGN] habitat animal
[Termes IGN] image SPOT 5
[Termes IGN] Mammalia
[Termes IGN] pansharpening (fusion d'images)
[Termes IGN] régression
[Termes IGN] texture d'imageRésumé : (Auteur) Forested stand structure is an important target variable within the fields of wildlife ecology. Remote sensing has often been suggested as a viable alternative to time consuming field and aerial investigations to determine forest structural attributes. In this study, 44 stands of recently harvested, regenerating, and old growth forest within the Foothills Model Forest in west-central Alberta were selected to test the ability of pan-sharpened SPOT-5 spectral response to classify stand structure. For each stand, a Structural Complexity Index (SCI) was calculated from field data using principal components analysis. To complement the spectral response data set and further increase accuracy, the normalized difference moisture index (NDMI) and three window sizes (55, 1111, and 2525) of first- (mean and standard deviation) and second-order (homogeneity, entropy, contrast, and correlation) textural measures were calculated over the pan-sharpened image. Stepwise multivariate regression analysis was used to determine the best explanatory model of the SCI using the spectral and textural data. The NDMI, first-order standard deviation and second-order correlation texture measures were better able to explain differences in SCI among the 44 forest stands (r2 = 0.79). The most appropriate window size for the texture measures was 55 indicating that this is a measure only detectable at a very high spatial resolution. The resulting classified SCI values were comparable to the actual field level SCI (r2 = 0.74, p = 0.01) and were limited by the strong variability within stands. Future research may find this measure useful either as a separate parameter or as an indicator of forest age for use in wildlife habitat modelling. Copyright Taylor & Francis Numéro de notice : A2007-447 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160701244849 En ligne : https://doi.org/10.1080/01431160701244849 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28810
in International Journal of Remote Sensing IJRS > vol 28 n°19-20 (October 2007) . - pp 4351 - 4364[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 080-07111 RAB Revue Centre de documentation En réserve L003 Disponible Spatial aspects of MRSA epidemiology: a case study using stochastic simulation, kernel estimation and SaTScan / Lucy Bastin in International journal of geographical information science IJGIS, vol 21 n° 6-7 (july 2007)
[article]
Titre : Spatial aspects of MRSA epidemiology: a case study using stochastic simulation, kernel estimation and SaTScan Type de document : Article/Communication Auteurs : Lucy Bastin, Auteur ; J. Rollason, Auteur ; A. Hilton, Auteur ; et al., Auteur Année de publication : 2007 Article en page(s) : pp 811 - 836 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG
[Termes IGN] analyse de groupement
[Termes IGN] analyse spatiale
[Termes IGN] épidémie
[Termes IGN] estimation par noyau
[Termes IGN] Grande-Bretagne
[Termes IGN] maladie bactérienne
[Termes IGN] simulation
[Termes IGN] surveillance sanitaireRésumé : (Auteur) The identification of disease clusters in space or space-time is of vital importance for public health policy and action. In the case of methicillin-resistant Staphylococcus aureus (MRSA), it is particularly important to distinguish between community and health care-associated infections, and to identify reservoirs of infection. 832 cases of MRSA in the West Midlands (UK) were tested for clustering and evidence of community transmission, after being geo-located to the centroids of UK unit postcodes (postal areas roughly equivalent to Zip+4 zip code areas). An age-stratified analysis was also carried out at the coarser spatial resolution of UK Census Output Areas. Stochastic simulation and kernel density estimation were combined to identify significant local clusters of MRSA (p Numéro de notice : A2007-273 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810601135767 En ligne : https://doi.org/10.1080/13658810601135767 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28636
in International journal of geographical information science IJGIS > vol 21 n° 6-7 (july 2007) . - pp 811 - 836[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 079-07041 RAB Revue Centre de documentation En réserve L003 Disponible 079-07042 RAB Revue Centre de documentation En réserve L003 Disponible Monitoring cross-border trails using airborne digital multispectral imagery and interactive image analysis techniques / L. Cao in Geocarto international, vol 22 n° 2 (June - August 2007)
[article]
Titre : Monitoring cross-border trails using airborne digital multispectral imagery and interactive image analysis techniques Type de document : Article/Communication Auteurs : L. Cao, Auteur ; D. Stow, Auteur ; J. Kaiser, Auteur ; et al., Auteur Année de publication : 2007 Article en page(s) : pp 107 - 125 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse en composantes principales
[Termes IGN] Californie (Etats-Unis)
[Termes IGN] frontière
[Termes IGN] image ADAR
[Termes IGN] image aérienne
[Termes IGN] image multibande
[Termes IGN] immigration
[Termes IGN] Mexique
[Termes IGN] sentierRésumé : (Auteur) The objective of this study was to evaluate image-based procedures for monitoring cross-border foot trails in the US - Mexico border zone in eastern San Diego County using airborne remote sensing techniques. Specifically, digital multi-spectral and multi-temporal imagery from an airborne digital multi-spectral imaging system, digital image processing, and visual image analysis techniques were explored in the context of detecting and delineating new trail features and updating trail GIS layers. Three trail updating approaches: map-to-image (M-I) overlay, map and image-to-image (M/I-I) differencing, map and image-to-image (M/I-I) swiping and two types of spectral transform, PCA and NDVI, were tested and compared. The M-I overlay was found to be the most reliable trail updating approach. The optimal image enhancement method for the M-I overlay approach varied with vegetation structure. PCA imagery yielded better results than NDVI imagery in a highly disturbed area and NDVI imagery performed better in a densely vegetated area. The M/I-I swiping approach was useful for distinguishing misregistered extant trails from new trail features. Copyright Taylor & Francis Numéro de notice : A2007-460 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106040701204073 Date de publication en ligne : 18/06/2007 En ligne : https://doi.org/10.1080/10106040701204073 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28823
in Geocarto international > vol 22 n° 2 (June - August 2007) . - pp 107 - 125[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 059-07021 RAB Revue Centre de documentation En réserve L003 Disponible Evaluating the uncertainty caused by Post Office Box addresses in environmental health studies: A restricted Monte Carlo approach / X. Shi in International journal of geographical information science IJGIS, vol 21 n° 3-4 (march - april 2007)PermalinkNET-DBSCAN: clustering the nodes of a dynamic linear network / Emmanuel Stefanakis in International journal of geographical information science IJGIS, vol 21 n° 3-4 (march - april 2007)PermalinkFFT-enhanced IHS transform method for fusing high-resolution satellite images / Y. Ling in ISPRS Journal of photogrammetry and remote sensing, vol 61 n° 6 (February 2007)PermalinkDEM resolution dependencies of terrain attributes across a landscape / Y. Deng in International journal of geographical information science IJGIS, vol 21 n° 1-2 (january 2007)PermalinkEGC'07, 7èmes journées francophones Extraction et gestion des connaissances, 23 - 26 janvier 2007, Namur, Belgique / Jérôme Euzenat (2007)PermalinkERS-2 SAR and IRS-1C LISS III data fusion: a PCA approach to improve remote sensing based geological interpretation / T.J. Majumdar in ISPRS Journal of photogrammetry and remote sensing, vol 61 n° 5 (January 2007)PermalinkEtude sur la généralisation automatique des carrefours routiers complexes / Jérémy Renard (2007)PermalinkFast cluster polygonization and its applications in data-rich environments / I. Lee in Geoinformatica, vol 10 n° 4 (December 2006)PermalinkAgent-based modelling of shifting cultivation field patterns, Vietnam / M.R. Jepsen in International journal of geographical information science IJGIS, vol 20 n° 9 (october 2006)PermalinkPopulation landscape: a geometric approach to studying spatial patterns of the US urban hierarchy / L. Mu in International journal of geographical information science IJGIS, vol 20 n° 6 (july 2006)Permalink