Descripteur
Documents disponibles dans cette catégorie (153)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
Etendre la recherche sur niveau(x) vers le bas
Titre : Spatial data quality : from description to application Type de document : Thèse/HDR Auteurs : Pepijn Van Oort, Auteur Editeur : Delft : Netherlands Geodetic Commission NGC Année de publication : 2005 Collection : Netherlands Geodetic Commission Publications on Geodesy, ISSN 0165-1706 num. 60 Importance : 125 p. Format : 17 x 24 cm ISBN/ISSN/EAN : 978-90-6132-295-5 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Infrastructure de données
[Termes IGN] base de données d'occupation du sol
[Termes IGN] covariance
[Termes IGN] données localisées
[Termes IGN] erreur de classification
[Termes IGN] généalogie des données
[Termes IGN] incertitude des données
[Termes IGN] occupation du sol
[Termes IGN] précision de la classification
[Termes IGN] qualité des données
[Termes IGN] terminologie
[Termes IGN] varianceRésumé : (Auteur) The growing availability of spatial data along with growing ease to use the spatial data (thanks to wide-scale adoption of GIS) have made it possible to use spatial data in applications inappropriate considering the quality of the data. As a result, concerns about spatial data quality have increased. To deal with these concerns, it is necessary to (1) formalise and standardise descriptions of spatial data quality and (2) to apply these descriptions in assessing the suitability (fitness for use) of spatial data, before using the data. The aim of this thesis was twofold: (1) to enhance the description of spatial data quality and (2) to improve our understanding of the implications of spatial data quality.
Chapter 1 sets the scene with a discussion on uncertainty and an explanation of why concerns about spatial data quality exist. Knowledge gaps are identified and the chapter concludes with six research questions.
Chapter 2 presents an overview of definitions of spatial data quality. Overall, I found a strong agreement on which elements together define spatial data quality. Definitions appear to differ in two aspects: (1) the location within the meta-data report: some elements occur not in the spatial data quality section but in another section of the meta-data report-, and (2) the explicitness with which elements are recognised as individual elements. For example, the European pre-standard explicitly recognises the element 'homogeneity'. Other standards recognise the importance of documenting the variation in quality, without naming it explicitly as an individual element.
In chapter 3, we quantified the spatial variability in classification accuracy for the agricultural crops in the Dutch national land cover database (LGN). Classification accuracy was significantly correlated with: (1) the crop present according to LGN, (2) the homogeneity of the 8-cell neighbourhood around each cell, (3) the size of the patch in which a cell is located, and (4) the heterogeneity of the landscape in which a cell is located.
In chapter 4, I present methods that use error matrices and change detection error matrices as input to make more accurate land cover change estimates. It was shown that temporal correlation in classification errors has a significant impact and must be taken into account. Producers of lime series land cover data are recommended not only to report error matrices, but also change detection error matrices.
Chapter 5 focuses on positional accuracy and area estimates. From the positional accuracy of vertices delineating polygons, the variance and covariance in area can be derived. Earlier studies derived equations for the variance, this chapter presents a covariance equation. The variance and covariance equation were implemented in a model and applied in a case-study. The case-study consisted of 97 polygons with a small subsidy value (in euros per hectare) assigned to each polygon. With the model we could calculate the uncertainty in the total subsidy value (in euros) of the complete set of polygons as a consequence of uncertainty in the position of vertices.
Chapter 6 explores the relationship between completeness of spatial data and risk in digging activities around underground cables and pipelines. A model is presented for calculating the economic implications of over- and incompleteness. An important element of this model is the relationship between detection lime and costs. The model can be used to calculate the optimal detection time, i.e. the time at which expected costs are at their minimum.
Chapter 7 addresses the question why risk analysis (RA) is so rarely applied to assess the suitability of spatial data prior to using the data. In theory, the use of RA is beneficial because it allows the user to judge if the use of certain spatial data does not produce unacceptable risks. Frequently proposed hypotheses explaining the scarce adoption of RA are all technical and educational. In chapter 7 we propose a new group of hypotheses, based on decision theory. We found that the willingness to spend resources on RA depends (1) on the presence of feedback mechanisms in the decision-making process, (2) on how much is at stake and (3) to a minor extent on how well the decision-making process can be modelled.
Chapter 8 prescrits conclusions on the six research questions (chapters 2-7) and lists recommendations for users, producers and researchers of spatial data. With regard to the description, four recommendations are given. Firstly, spend more effort on documenting the lineage of reference data. Secondly, quantify and report correlation of quality between related data sets. Thirdly, investigate the integration of different forms of uncertainty (error, vagueness, ambiguity). Fourthly, study the implementation and use of spatial data quality standards. With regard to the application of spatial data quality descriptions, I have two main recommendations. Firstly, to continue the line of research followed in this thesis: quantification of implications of spatial data quality, through development of theory along with tangible illustrations in case-studies. Secondly, there is a need for more empirical research into how users cope with spatial data quality.Numéro de notice : 13261 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Thèse étrangère DOI : sans En ligne : https://www.ncgeo.nl/downloads/60Oort.pdf Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54944 Réservation
Réserver ce documentExemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 13261-02 37.00 Livre Centre de documentation Géomatique Disponible 13261-01 37.00 Livre Centre de documentation Géomatique Disponible The development of superspectral approaches for the improvement of land cover classification / M. Gianinetto in IEEE Transactions on geoscience and remote sensing, vol 42 n° 11 (November 2004)
[article]
Titre : The development of superspectral approaches for the improvement of land cover classification Type de document : Article/Communication Auteurs : M. Gianinetto, Auteur ; G. Lechi, Auteur Année de publication : 2004 Article en page(s) : pp 2670 - 2679 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] bande infrarouge
[Termes IGN] capteur imageur
[Termes IGN] classification dirigée
[Termes IGN] cultures
[Termes IGN] filtrage du bruit
[Termes IGN] image EO1-Hyperion
[Termes IGN] image hyperspectrale
[Termes IGN] image MIVIS
[Termes IGN] Italie
[Termes IGN] Kappa de Cohen
[Termes IGN] occupation du sol
[Termes IGN] onde électromagnétique
[Termes IGN] précision de la classification
[Termes IGN] rapport signal sur bruitRésumé : (Auteur) This paper develops a critical review of the hyperspectral splitting of the solar reflected radiation acquired by hyperspectral imaging sensors. The bandwidth used in the range from 2.0-2.5 um by many hyperspectral sensors sometimes is too narrow for land cover classification. In fact, hyperspectral imagers often suffer from low signal-to-noise (SNR) in the short-wave infrared region of the electromagnetic spectrum, resulting in noisy image collection. This paper presents a new methodological approach to the splitting of the solar reflected radiation, called the "superspectral approach" It is based on the principle of increasing the channel bandwidth by increasing the number of wavelengths, to build synthetic spectral bands with higher SNR. The methodology has been applied to the Multispectral Infrared and Visible Imaging Spectrometer (MIVIS) sensor, an airborne hyperspectral scanner used for environmental remote sensing applications in Italy. Interesting results have been achieved in crop classification, processing the Cordenons survey carried out in August 2001 in the northeastern part of Italy. The Spectral Angle Mapper algorithm was used for classification because it is insensitive to shadows. For accuracy assessment, the overall accuracy (OA) and kappa coefficient (k) were calculated and used in the comparison. Using the superspectral approach, an increment in the overall accuracy of about 42 % and an increment in the kappa coefficient of about 51 % were obtained in comparison to the classification accuracy of unprocessed original MIVIS data (OA = 41.21, k = 0.35). A second case study is presented using the National Aeronautics and Space Administration's experimental hyperspectral imager HYPERION. Data acquired over the lake of Garda (Italy) in October 2002 was processed with the superspectral approach. Comparing the simulated HYPERION superspectral bands with the original data, SNR improvements are achieved in the shortwave infrared region (from 0.7-54.2 for 2.012-pm wavelength and from 0.7-64.5 for the 2.365-pm wavelength). The methodology proposed is sensor independent and can be applied to any of the hyperspectral sensors currently available. Numéro de notice : A2004-464 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2004.835347 En ligne : https://doi.org/10.1109/TGRS.2004.835347 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26984
in IEEE Transactions on geoscience and remote sensing > vol 42 n° 11 (November 2004) . - pp 2670 - 2679[article]Réservation
Réserver ce documentExemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 065-04111 RAB Revue Centre de documentation En réserve L003 Disponible Spatial variability in classification accuracy of agricultural crops in the Dutch national land-cover database / A.J.W. Van Oort in International journal of geographical information science IJGIS, vol 18 n° 6 (october 2004)
[article]
Titre : Spatial variability in classification accuracy of agricultural crops in the Dutch national land-cover database Type de document : Article/Communication Auteurs : A.J.W. Van Oort, Auteur ; Arnold K. Bregt, Auteur ; et al., Auteur Année de publication : 2004 Article en page(s) : pp 611 - 626 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie numérique
[Termes IGN] base de données d'occupation du sol
[Termes IGN] base de données localisées
[Termes IGN] classe d'objets
[Termes IGN] cultures
[Termes IGN] données maillées
[Termes IGN] occupation du sol
[Termes IGN] Pays-Bas
[Termes IGN] paysage
[Termes IGN] pixel
[Termes IGN] précision de la classificationRésumé : (Auteur) Variability in per cell classification accuracy is predominantly modelled with landcover class as the explanatory variable, i.e. with users' accuracies from the error matrix. Logistic regression models were developed to include other explanatory variables: heterogeneity in the 3 x 3 window around a cell, the size of the patch and the complexity of the landscape in which a cell is located. It was found that per cell, the probability of correct classification was significantly (a = 0.05) higher for cells with a less heterogeneous neighbourhood, for cells part of larger patches and for cells in regions with a less heterogeneous landscape. To validate the models, a leave-one-out procedure was applied in which the absolute difference between the actual and the model-estimated number of cells correctly classified was summarized over 55 regions in the Netherlands. The sum of differences reduced from 60.9 to 48.1 after adding the variables 'patch size' and 'landscape dominance' to the land-cover class model. Spatial variability thus modelled therefore led to a substantial improvement in the estimation of the per cell classification accuracy. Numéro de notice : A2004-353 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810410001701969 En ligne : https://doi.org/10.1080/13658810410001701969 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26880
in International journal of geographical information science IJGIS > vol 18 n° 6 (october 2004) . - pp 611 - 626[article]Réservation
Réserver ce documentExemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 079-04061 RAB Revue Centre de documentation En réserve L003 Disponible 079-04062 RAB Revue Centre de documentation En réserve L003 Disponible Wavelet for urban spatial feature discrimination: comparisons with fractal, spatial autocorrelation, and spatial co-occurrence approaches / Nina S.N. Lam in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 7 (July 2004)
[article]
Titre : Wavelet for urban spatial feature discrimination: comparisons with fractal, spatial autocorrelation, and spatial co-occurrence approaches Type de document : Article/Communication Auteurs : Nina S.N. Lam, Auteur ; S.W. Myint, Auteur ; J.M. Tyler, Auteur Année de publication : 2004 Article en page(s) : pp 803 - 812 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse fractale
[Termes IGN] autocorrélation spatiale
[Termes IGN] classification dirigée
[Termes IGN] image multibande
[Termes IGN] matrice
[Termes IGN] milieu urbain
[Termes IGN] précision de la classification
[Termes IGN] transformation en ondelettesRésumé : (Auteur) Traditional image processing techniques have proven inadequate for urban mapping using high spatial resolution remote-sensing images. This study examined and evaluated wavelet transforms for urban texture analysis and image classification using high spatial resolution ATLAS imagery. For the purpose of comparison and to evaluate the effectiveness of the wavelet approaches, two different fractal approaches (isarithm and triangular prism), spatial autocorrelation (Moran's I and Geary's C), and spatial co-occurrence matrix of the selected urban classes were examined using 65 X 65, 33 X 33, and 17 X 17 samples with a pixel size of 2.5 m. Results from this study suggest that a multi-band and multi-level wavelet approach can be used to drastically increase the classification accuracy. The fractal techniques did not provide satisfactory classification accuracy. Spatial autocorrelation and spatial co-occurrence techniques were found to be relatively effective when compared to the fractal approaches. It can be concluded that the wavelet transform approach is the most accurate of all four approaches. Numéro de notice : A2004-273 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.70.7.803 En ligne : https://doi.org/10.14358/PERS.70.7.803 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26800
in Photogrammetric Engineering & Remote Sensing, PERS > vol 70 n° 7 (July 2004) . - pp 803 - 812[article]Examining the effect of spatial resolution and texture window size on classification accuracy: an urban environment case / D. Chen in International Journal of Remote Sensing IJRS, vol 25 n° 11 (June 2004)
[article]
Titre : Examining the effect of spatial resolution and texture window size on classification accuracy: an urban environment case Type de document : Article/Communication Auteurs : D. Chen, Auteur ; D.A. Stow, Auteur ; P. Gong, Auteur Année de publication : 2004 Article en page(s) : pp 2177 - 2092 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse comparative
[Termes IGN] classification par maximum de vraisemblance
[Termes IGN] image multibande
[Termes IGN] limite de résolution géométrique
[Termes IGN] limite de résolution spectrale
[Termes IGN] milieu urbain
[Termes IGN] occupation du sol
[Termes IGN] périphérie urbaine
[Termes IGN] précision de la classification
[Termes IGN] San Diego
[Termes IGN] texture d'imageRésumé : (Auteur) The purpose of this paper is to evaluate spatial resolution effects on image classification. Classification maps were generated with a maximum likelihood (ML) classifier applied to three multi-spectral bands and variance texture images. A total of eight urban land use/cover classes were obtained at six spatial resolution levels based on a series of aggregated Colour Infrared Digital Orthophoto Quarter Quadrangle (DOQQ) subsets in urban and rural fringe areas of the San Diego metropolitan area. The classification results were compared using overall and individual classification accuracies. Classification accuracies were shown to be influenced by image spatial resolution, window size used in texture extraction and differences in spatial structure within and between categories. The more heterogeneous arc the land use/cover units and the more fragmented are the landscapes, the finer the resolution required. Texture was more effective for improving the classification accuracy of land use classes at finer resolution levels. For spectrally homogeneous classes, a small window is preferable. But for spectrally heterogeneous classes, a large window size is required. Numéro de notice : A2004-230 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160310001618464 En ligne : https://doi.org/10.1080/01431160310001618464 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26757
in International Journal of Remote Sensing IJRS > vol 25 n° 11 (June 2004) . - pp 2177 - 2092[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04091 RAB Revue Centre de documentation En réserve L003 Exclu du prêt Sub-pixel mapping and sub-pixel sharpening using neural network predicted wavelet coefficients / K.C. Mertens in Remote sensing of environment, vol 91 n° 2 (30/05/2004)PermalinkNonparametric weighted feature extraction for classification / D.A. Landgrebe in IEEE Transactions on geoscience and remote sensing, vol 42 n° 5 (May 2004)PermalinkThematic map comparison: evaluating the statistical significance of differences in classification accuracy / Giles M. Foody in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 5 (May 2004)PermalinkClassification of remotely sensed imagery stochastic gradient boosting as a refinement of classification tree analysis / R. Lawrence in Remote sensing of environment, vol 90 n° 3 (15/04/2004)PermalinkUsing quadtree segmentation to support error modelling in categorical raster data / S. De Bruin in International journal of geographical information science IJGIS, vol 18 n° 2 (march 2004)PermalinkUnsupervised classification of hyperspectral data: an ICA mixture model based approach / Chintan A. Shah in International Journal of Remote Sensing IJRS, vol 25 n° 2 (January 2004)PermalinkPredicting missing field boundaries to increase per-field classification accuracy / Paul Aplin in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 1 (January 2004)PermalinkA Markov random field approach to spatio-temporal contextual image classification / F. Melgani in IEEE Transactions on geoscience and remote sensing, vol 41 n° 11 (November 2003)PermalinkStrategies for integrating information from multiple resolutions into land-use/land-cover classification routines / D.M. Chen in Photogrammetric Engineering & Remote Sensing, PERS, vol 69 n° 11 (November 2003)PermalinkImprovements to urban area characterization using multitemporal and multiangle SAR images / F. Dell'acqua in IEEE Transactions on geoscience and remote sensing, vol 41 n° 9 (September 2003)PermalinkSpectral resolution requirements for mapping urban areas / Martin Herold in IEEE Transactions on geoscience and remote sensing, vol 41 n° 9 (September 2003)PermalinkImpact of topographic normalization on land-cover classification accuracy / S.R. Hale in Photogrammetric Engineering & Remote Sensing, PERS, vol 69 n° 7 (July 2003)PermalinkEvaluation of airborne video data for land-cover classification accuracy assessment / I.T. Grierson in Geocarto international, vol 18 n° 2 (June - August 2003)PermalinkLand cover classification models using Shuttle Imaging Radar (SIR-C) data: a case study in New Hampshire, USA / R. Narayanan in Geocarto international, vol 17 n° 3 (September - November 2002)PermalinkBest-bases feature extraction algorithms for classification of hyperspectral data / Satish Kumar in IEEE Transactions on geoscience and remote sensing, vol 39 n° 7 (July 2001)PermalinkRadar and optical data integration for land-use-land-cover mapping / Barry N. Haack in Photogrammetric Engineering & Remote Sensing, PERS, vol 66 n° 6 (June 2000)PermalinkQualité de l'occupation des sols / José Devers (1998)PermalinkThematic Mapper thermal infrared data in discriminating selected urban features / S.M. Leak in International Journal of Remote Sensing IJRS, vol 11 n° 5 (May 1990)PermalinkThe use of structural information for improving land-cover classification accuracies at the rural-urban fringe / P. Gong in Photogrammetric Engineering & Remote Sensing, PERS, vol 56 n° 1 (january 1990)PermalinkA comparison of classification algorithms in terms of speed and accuracy after the application of a post-classification modal filter / D.J. Booth in International Journal of Remote Sensing IJRS, vol 10 n° 7 (July 1989)Permalink