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Auteur Q. Zhou |
Documents disponibles écrits par cet auteur (5)
Ajouter le résultat dans votre panier Affiner la recherche Interroger des sources externesGeneralization of DEM for terrain analysis using a compound method / Q. Zhou in ISPRS Journal of photogrammetry and remote sensing, vol 66 n° 1 (January - February 2011)
Titre : Generalization of DEM for terrain analysis using a compound method Type de document : Article/Communication Auteurs : Q. Zhou, Auteur ; Y. Chen, Auteur Année de publication : 2011 Article en page(s) : pp 38 - 45 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] erreur moyenne quadratique
[Termes IGN] généralisation automatique de données
[Termes IGN] généralisation de MNT
[Termes IGN] modèle numérique de surface
[Termes IGN] Triangulated Irregular NetworkRésumé : (Auteur) This paper reports an investigation into the generalization of a grid-based digital elevation model (DEM) for the purpose of terrain analysis. The focus is on the method of restructuring the grid-based surface elevation data to form a triangulated irregular network (TIN) that is optimized to keep the important terrain features and slope morphology with the minimum number of sample points. The critical points of the terrain surface are extracted from the DEM based on their significance, measured not only by their local relief, but also by their importance in identifying inherent geomorphological and drainage features in the DEM. A compound method is proposed by integrating the traditional point-additive and feature-point methods to construct a drainage-constrained TIN. The outcome is then compared with those derived from other selected methods including filtering, point-additive or feature-point algorithms. The results show that the compound approach is capable of taking advantage of both point-additive and feature-point algorithms to maximally keep the terrain features and to maintain RMSE at an acceptable level, while reducing the elevation data points by over 99%. The analytical result also shows that the proposed method outperforms the compared methods with better control in retaining drainage features at the same level of RMSE. Numéro de notice : A2011-015 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2010.08.005 En ligne : https://doi.org/10.1016/j.isprsjprs.2010.08.005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30797
in ISPRS Journal of photogrammetry and remote sensing > vol 66 n° 1 (January - February 2011) . - pp 38 - 45[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 081-2011011 SL Revue Centre de documentation Revues en salle Disponible
Titre : Terrain complexity and uncertainties in grid-based digital terrain analysis Type de document : Article/Communication Auteurs : Q. Zhou, Auteur ; X. Liu, Auteur ; Y. Sun, Auteur Année de publication : 2006 Article en page(s) : pp 1137 - 1147 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] complexité
[Termes IGN] incertitude géométrique
[Termes IGN] modèle d'erreur
[Termes IGN] modèle numérique de terrain
[Termes IGN] pente
[Termes IGN] reliefRésumé : (Auteur) The objective of this research is to study the relationship between terrain complexity and terrain analysis results from grid-based digital elevation models (DEMs). The impact of terrain complexity represented by terrain steepness and orientation on derived parameters such as slope and aspect has been analysed. Experiments have been conducted to quantify the uncertainties created by digital terrain analysis algorithms. The test results show that (a) the RMSE of derived slope and aspect is negatively correlated with slope steepness; (b) the RMSE of derived aspect is more sensitive to terrain complexity than that of derived slope; and (c) the uncertainties in derived slope and aspect tend to be found in flatter areas, and decrease with increasing terrain complexity. The study shows that although primary surface parameters can be well defined mathematically, the implementation of those mathematical models in a GIS environment may generate considerable uncertainties related to terrain complexity. In general, when terrain is rugged with steep slopes, the uncertainty of derived parameters is quite minimal. While in flatter areas, the DEM-based derivatives, particularly the aspect, may contain a great amount of uncertainty, causing significant limitation in applying the analytical results. Copyright Taylor & Francis Numéro de notice : A2006-453 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/13658810600816573 En ligne : https://doi.org/10.1080/13658810600816573 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28177
in International journal of geographical information science IJGIS > vol 20 n° 10 (november 2006) . - pp 1137 - 1147[article]Exemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 079-06101 RAB Revue Centre de documentation En réserve L003 Disponible 079-06102 RAB Revue Centre de documentation En réserve L003 Disponible
Titre : Accuracy analysis of remote sensing change detection by rule-based rationality evaluation with post-classification comparison Type de document : Article/Communication Auteurs : H. Liu, Auteur ; Q. Zhou, Auteur Année de publication : 2004 Article en page(s) : pp 1037 - 1050 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] classification
[Termes IGN] détection de changement
[Termes IGN] estimation de précision
[Termes IGN] image multitemporelle
[Termes IGN] Kappa de Cohen
[Termes IGN] zone urbaineRésumé : (Auteur) Accuracy assessment for remote sensing classification is commonly based on using an error matrix, or confusion table, which needs reference, or 'ground truthing', data to support. When undertaking change detection using numerous multi-temporal images, it is often difficult to make the accuracy assessment by the 'traditional' method, which typically requires simultaneous collection of reference data. In this study, we propose a new approach by arguing change rationality with post-classification comparison. Multitemporal Landsat TM images were classified for land use in an urban fringe area of Beijing, China and the post-classification comparison of these classified images shows change trajectories through the time series. These change trajectories were then analysed by assessing their rationality against a set of logical rules to separate cases of 'real land use change' and possible classification errors. The analvsis results show that the overall accuracy for land use change in the urban fringe area was 86%, with a fuzziness of 7%. Although it is argued that the uncertainty, still exists on classification accuracy assessed by this method. It nevertheless provides an alternative approach for more reasonable assessment when ideal simultaneous 'ground truthing' is not available. Numéro de notice : A2004-081 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/0143116031000150004 En ligne : https://doi.org/10.1080/0143116031000150004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26609
in International Journal of Remote Sensing IJRS > vol 25 n° 5 (March 2004) . - pp 1037 - 1050[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04051 RAB Revue Centre de documentation En réserve L003 Exclu du prêt
Titre : Error assessment of grid-based flow routing algorithms used in hydrological models Type de document : Article/Communication Auteurs : Q. Zhou, Auteur ; X. Liu, Auteur Année de publication : 2002 Article en page(s) : pp 819 - 842 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] erreur
[Termes IGN] modèle hydrographique
[Termes IGN] modèle numérique de surface
[Termes IGN] pente
[Termes IGN] ruissellementRésumé : (Auteur) This paper reports an investigation on the accuracy of gridbased routing algorithms used in hydrological models. A quantitative methodology has been developed for objective and dataindependent assessment of errors generated from the algorithms that extract hydrological parameters from gridded DEM. The generic approach is to use artificial surfaces that can be described by a mathematical model, thus the 'true' output value can be predetermined to avoid uncertainty caused by uncontrollable data errors. Four mathematical surfaces based on all ellipsoid (representing convex slopes), an inverse ellipsoid (representing concave slopes), saddle and plane were generated and the theoretical 'true' value of the Specific Catchment Area (SCA) at any given point on the surfaces could be computed using mathematical inference. Based on these models, tests were made on a number of algorithms for SCA computation. The actual output values from these algorithms on the convex, concave, saddle and plane surfaces were compared with the theoretical 'true' values, and the errors were then analysed statistically. The strengths and weaknesses of the selected algorithms are also discussed. Numéro de notice : A2002-261 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/13658810210149425 En ligne : https://doi.org/10.1080/13658810210149425 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22172
in International journal of geographical information science IJGIS > vol 16 n° 8 (december 2002) . - pp 819 - 842[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 079-02081 RAB Revue Centre de documentation En réserve L003 Disponible
Titre : Optimal spatial decision making using GIS: a prototype of a Real Estate Geographical Information System (REGIS) Type de document : Article/Communication Auteurs : T.Q. Zeng, Auteur ; Q. Zhou, Auteur Année de publication : 2001 Article en page(s) : pp 307 - 321 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique
[Termes IGN] aide à la décision
[Termes IGN] immobilier (secteur)
[Termes IGN] logique floue
[Termes IGN] sous ensemble flou
[Termes IGN] système d'information géographiqueRésumé : (Auteur) In the real estate business, it is a common understanding that the value and potential of a property are fundamentally determined by its location. This emphasises the significance of spatial factors in decision making in real estate. A geographical information system (GIS) is undoubtedly useful in this decision making. This paper reports on the development of a prototype real estate GIS (REGIS) by integrating fuzzy set (FZ) theory, a rule-based system (RBS) and GIS. The role of this system in the real estate business is in assisting decision makers for sellers and buyers, as well as property managers. For real estate agencies, the system can be used as an aid to selling and managing properties. For the buyers, the REGIS can function as a consultant in their decision making in purchasing properties. Methodologies are demonstrated using case studies. Developed as a generic tool with capabilities to deal with uncertainties, this prototype REGIS can also be applied to other fields, which involves optimal spatial decision making. Numéro de notice : A2001-040 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article DOI : 10.1080/136588101300304034 En ligne : https://doi.org/10.1080/136588101300304034 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=21742
in International journal of geographical information science IJGIS > vol 15 n° 4 (june 2001) . - pp 307 - 321[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 079-01041 RAB Revue Centre de documentation En réserve L003 Disponible
