Centre de documentation
scientifique

Improving soil moisture profile prediction with the particle Filter-Markov chain Monte Carlo method / Hongxiang Yan in IEEE Transactions on geoscience and remote sensing, vol 53 n° 11 (November 2015)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 53 n° 11 (November 2015) . - pp 6134 - 6147 Titre : Improving soil moisture profile prediction with the particle Filter-Markov chain Monte Carlo method Type de document : Article/Communication Auteurs : Hongxiang Yan, Auteur ; Caleb M. DeChant, Auteur ; Hamid Moradkhani, Auteur Année de publication : 2015 Article en page(s) : pp 6134 - 6147 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] humidité du sol [Termes IGN] image Aqua-AMSR [Termes IGN] méthode de Monte-Carlo par chaînes de Markov Résumé : (Auteur) Satellite soil moisture estimates have received increasing attention over the past decade. This paper examines the applicability of estimating soil moisture states and soil hydraulic parameters through two particle filter (PF) methods: The PF with commonly used sampling importance resampling (PF-SIR) and the PF with recently developed Markov chain Monte Carlo sampling (PF-MCMC) methods. In a synthetic experiment, the potential of assimilating remotely sensed near-surface soil moisture measurements into a 1-D mechanistic soil water model (HYDRUS-1D) using both the PF-SIR and PF-MCMC algorithms is analyzed. The effects of satellite temporal resolution and accuracy, soil type, and ensemble size on the assimilation of soil moisture are analyzed. In a real data experiment, we first validate the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) soil moisture products in the Oklahoma Little Washita Watershed. Aside from rescaling the remotely sensed soil moisture, a bias correction algorithm is implemented to correct the deep soil moisture estimate. Both the ascending and descending AMSR-E soil moisture data are assimilated into the HYDRUS-1D model. The synthetic assimilation results indicated that, whereas both updating schemes showed the ability to correct the soil moisture state and estimate hydraulic parameters, the PF-MCMC scheme is consistently more accurate than PR-SIR. For real data case, the quality of remotely sensed soil moisture impacts the benefits of their assimilation into the model. The PF-MCMC scheme brought marginal gains than the open-loop simulation in RMSE at both surface and root-zone soil layer, whereas the PF-SIR scheme degraded the open-loop simulation. Numéro de notice : A2015-777 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2015.2432067 Date de publication en ligne : 02/06/2015 En ligne : https://doi.org/10.1109/TGRS.2015.2432067 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=78883 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-2015111	SL	Revue	Centre de documentation	Revues en salle	Disponible

A multi-parameter approach to automated building grouping and generalization / Hongxiang Yan in Geoinformatica, vol 12 n° 1 (March - May 2008)  

Public [article]  inGeoinformatica > vol 12 n° 1 (March - May 2008) . - pp 73 - 89 Titre : A multi-parameter approach to automated building grouping and generalization Type de document : Article/Communication Auteurs : Hongxiang Yan, Auteur ; Robert Weibel, Auteur ; B. Yang, Auteur Année de publication : 2008 Article en page(s) : pp 73 - 89 Langues : Anglais (eng) Descripteur : [Termes IGN] détection du bâti [Termes IGN] diagramme de Voronoï [Termes IGN] généralisation cartographique automatisée [Termes IGN] généralisation du bâti [Termes IGN] triangulation de Delaunay [Vedettes matières IGN] Généralisation Résumé : (Auteur) This paper presents an approach to automated building grouping and generalization. Three principles of Gestalt theories, i.e. proximity, similarity, and common directions, are employed as guidelines, and six parameters, i.e. minimum distance, area of visible scope, area ratio, edge number ratio, smallest minimum bounding rectangle (SMBR), directional Voronoi diagram (DVD), are selected to describe spatial patterns, distributions and relations of buildings. Based on these principles and parameters, an approach to building grouping and generalization is developed. First, buildings are triangulated based on Delaunay triangulation rules, by which topological adjacency relations between buildings are obtained and the six parameters are calculated and recorded. Every two topologically adjacent buildings form a potential group. Three criteria from previous experience and Gestalt principles are employed to tell whether a 2-building group is ‘strong,’ ‘average’ or ‘weak.’ The ‘weak’ groups are deleted from the group array. Secondly, the retained groups with common buildings are organized to form intermediate groups according to their relations. After this step, the intermediate groups with common buildings are aggregated or separated and the final groups are formed. Finally, appropriate operators/algorithms are selected for each group and the generalized buildings are achieved. This approach is fully automatic. As our experiments show, it can be used primarily in the generalization of buildings arranged in blocks. Copyright Springer Numéro de notice : A2008-070 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-007-0020-5 En ligne : https://doi.org/10.1007/s10707-007-0020-5 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29065 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
057-08011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

A quantitative description model for direction relations based on direction groups / Hongxiang Yan in Geoinformatica, vol 10 n° 2 (June - August 2006)  

Public [article]  inGeoinformatica > vol 10 n° 2 (June - August 2006) . - pp 177 - 196 Titre : A quantitative description model for direction relations based on direction groups Type de document : Article/Communication Auteurs : Hongxiang Yan, Auteur ; Y. Chu, Auteur ; et al., Auteur Année de publication : 2006 Article en page(s) : pp 177 - 196 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Bases de données localisées [Termes IGN] diagramme de Voronoï [Termes IGN] modèle conceptuel de données localisées [Termes IGN] raisonnement spatial [Termes IGN] système d'information géographique [Termes IGN] triangulation de Delaunay Résumé : (Auteur) The description models for spatial relations, especially those for direction relations, have gained increasing attention in GIS and Cartography community in recent decades. In this paper, such a quantitative model for spatial direction relations is discussed. It has been suggested that people often describe directions between two objects using multiple directions but not a single one; therefore a description model for direction relations should use multiple directions, i.e., direction group. A direction group consists of two components: the azimuths of the normals of direction Voronoi edges between two objects and the corresponding weights of the azimuths. The former can be calculated by means of Delaunay triangulation of the vertices and the points of intersection of the two objects; the latter can be calculated using the common areas of the two objects or the lengths of their direction Voronoi diagram (DVD) edges. The advantages of this model exist in four aspects: (1) direction computations are converted into a 1-dimension space problem and use lines (DVDs) to solve it, therefore direction computation process is simplified; (2) once Dir(A,B), the directions from A to B, is obtained, Dir(B,A) can be got without complex computations; (3) a quantitative direction group can be transformed into a qualitative one easily; (4) quantitative direction relations between objects can be recorded in 2-dimension tables, which is very useful in spatial reasoning. Copyright Springer Numéro de notice : A2006-215 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1007/s10707-006-7578-1 En ligne : https://doi.org/10.1007/s10707-006-7578-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27942 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
057-06021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Automated building generalization based on urban morphology and gestalt theory / Z. Li in International journal of geographical information science IJGIS, vol 18 n° 5 (august 2004)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 18 n° 5 (august 2004) . - pp 513 - 534 Titre : Automated building generalization based on urban morphology and gestalt theory Type de document : Article/Communication Auteurs : Z. Li, Auteur ; Hongxiang Yan, Auteur ; Tinghua Ai, Auteur ; J. Chen, Auteur Année de publication : 2004 Article en page(s) : pp 513 - 534 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse spatiale [Termes IGN] base de données cartographiques [Termes IGN] diagramme de Voronoï [Termes IGN] généralisation cartographique automatisée [Termes IGN] généralisation du bâti [Termes IGN] morphologie mathématique [Termes IGN] reconnaissance de formes [Termes IGN] système d'information géographique [Termes IGN] théorie des graphes [Termes IGN] triangulation de Delaunay [Termes IGN] zone urbaine [Vedettes matières IGN] Généralisation Résumé : (Auteur) Building generalization is a difficult operation due to the complexity of the spatial distribution of buildings and for reasons of spatial recognition. In this study, building generalization is decomposed into two steps, i.e. building grouping and generalization execution. The neighbourhood model in urban morphology provides global constraints for guiding the global partitioning of building sets on the whole map by means of roads and rivers, by which enclaves, blocks, superblocks or neighbourhoods are formed, whereas the local constraints from Gestalt principles provide criteria for the further grouping of enclaves, blocks, superblocks and/or neighbourhoods. In the grouping process, graph theory, Delaunay triangulation and the Voronoi diagram are employed as supporting techniques. After grouping, some useful information, such as the sum of the building's area, the mean separation and the standard deviation of the separation of buildings, is attached to each group. By means of the attached information, an appropriate operation is selected to generalize the corresponding groups. Indeed, the methodology described brings together a number of welldeveloped theories/techniques, including graph theory, Delaunay triangulation, the Voronoi diagram, urban morphology and Gestalt theory, in such a way that multiscale products can be derived. Numéro de notice : A2004-285 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810410001702021 En ligne : https://doi.org/10.1080/13658810410001702021 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26812 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-04051	RAB	Revue	Centre de documentation	En réserve L003	Disponible