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Dépouillements

True ortho-image production for forested areas from large-scale aerial photographs / Y. Sheng in Photogrammetric Engineering & Remote Sensing, PERS, vol 69 n° 3 (March 2003)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 69 n° 3 (March 2003) . - pp 259 - 266 Titre : True ortho-image production for forested areas from large-scale aerial photographs Type de document : Article/Communication Auteurs : Y. Sheng, Auteur ; P. Gong, Auteur ; Gregory S. Biging, Auteur Année de publication : 2003 Article en page(s) : pp 259 - 266 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Orthophotographie, orthoimage [Termes IGN] correction des ombres [Termes IGN] couvert forestier [Termes IGN] déformation d'image [Termes IGN] dévers [Termes IGN] forêt [Termes IGN] modèle numérique de surface [Termes IGN] objet géographique 3D [Termes IGN] orthoimage [Termes IGN] orthoimage intégrale [Termes IGN] photographie à grande échelle [Termes IGN] photographie aérienne Résumé : (Auteur) An orthophoto is a fundamental information source in forestry. Orthophoto production is usally based on digital elevation models (DEM) ; however, the elevations of 3D objects suchs as buildings and trees, which are visible in large-scale photos, are not included in DEMs. Recently initiated "true orthophoto" generation has been dedicated to urban scenes, removing the displacement caused by both the terrain and buildings. This paper reports an effort on reducing occlusion and distortion caused by trees in true orthoimage generation for forested areas. Canopy surface models (CMS) depicting both the terrain and tree surfaces were used in forest orthoimage production. Z-buffer techniques were incorporated into indirect orthoimage production to remove occlusion. An angle-based strategy was applied to composite multi-occular images. The proposed techniques were applied in the generation of high-resolution orthoimages of redwood stand with 1:2 400-scale aerial photos. Numéro de notice : A2003-029 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.14358/PERS.69.3.259 En ligne : https://doi.org/10.14358/PERS.69.3.259 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22326 [article]

Mountain pine beetle red-attack forest damage classification using stratified Landsat TM data in British Columbia, Canada / Steven E. Franklin in Photogrammetric Engineering & Remote Sensing, PERS, vol 69 n° 3 (March 2003)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 69 n° 3 (March 2003) . - pp 283 - 288 Titre : Mountain pine beetle red-attack forest damage classification using stratified Landsat TM data in British Columbia, Canada Type de document : Article/Communication Auteurs : Steven E. Franklin, Auteur ; Michael A. Wulder, Auteur ; R.S. Skakun, Auteur ; A.L. Caroll, Auteur Année de publication : 2003 Article en page(s) : pp 283 - 288 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] carte forestière [Termes IGN] cartographie thématique [Termes IGN] classification par maximum de vraisemblance [Termes IGN] Colombie-Britannique (Canada) [Termes IGN] dommage matériel [Termes IGN] image Landsat-TM [Termes IGN] Insecta [Termes IGN] inventaire forestier (techniques et méthodes) [Termes IGN] inventaire forestier étranger (données) [Termes IGN] maladie phytosanitaire [Termes IGN] outil d'aide à la décision [Termes IGN] Pinus contorta [Termes IGN] sylviculture [Termes IGN] système d'information géographique Résumé : (Auteur) The identification and classification of mountain pine beetle, Dentroctonus ponderos (Hopkins), red-attack damage patterns in a mature lodgepole pine (Pinus contorta) forest located in the Forst St-James forest Distric, British Columbia, was accomplished using 1999 Landsat TM satellite imagery, 1999 mountain pine beetle field and aerial survey point data, and GIS forest inventory data. Unrelated variance in the observed spectral response at mountain pine beetle field and aerial survey points was reduced following image stratification with the GIS forest inventory data and removal of other factors uncharacteristic of red-attack damage. Locations of known mountain pine beetle infestation were used to train a maximum-likelihood algorithm ; overall classification accuracy was 73 percent, based on an assessment of 360 independent validation points. If local stand variability is reduced prior to signature generation, accuracies and mao products can be useful for those involved in active forest management decision making regarding mountain pine beetle infestations. Numéro de notice : A2003-030 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.14358/PERS.69.3.283 En ligne : https://doi.org/10.14358/PERS.69.3.283 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22327 [article]

Sampling method and sampling placement: how do they affect the accuracy of remotely sensed maps? / L. Plourde in Photogrammetric Engineering & Remote Sensing, PERS, vol 69 n° 3 (March 2003)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 69 n° 3 (March 2003) . - pp 289 - 297 Titre : Sampling method and sampling placement: how do they affect the accuracy of remotely sensed maps? Type de document : Article/Communication Auteurs : L. Plourde, Auteur ; Russell G. Congalton, Auteur Année de publication : 2003 Article en page(s) : pp 289 - 297 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Orthophotographie, orthoimage [Termes IGN] classification dirigée [Termes IGN] classification non dirigée [Termes IGN] échantillonnage d'image [Termes IGN] estimation de précision [Termes IGN] identification automatique [Termes IGN] précision de détermination de surface [Termes IGN] sylviculture Résumé : (Auteur) The accuracy of remote sensed forest stand maps is traditionnally assessed by comparing a sample of the map data with actual ground conditions. Samples most often comprise clusters of pixels within homogeneous areas , therby avoiding problems associated with accuratly maping "edges" (e.g., transition areas between two forest types). Consequentely, they may well overstimable accuracy, but the degree of overestimation is unknown. This paper examines two important factors regarding accuracy assessment that are not well studied : the effect on estimates of accuracy of (1) the sampling method and (2) the exact placement of the samples. Overall accuracy, normalized accuracy, and the KHAT statistic are computed from error matrices generated from simple random sampling, stratified random sampling, and systematic sampling using totally random sample placement and samples chosen from homogeneous areas only. The results indicate that Kappa appears to be appropriate to use with systematic sampling and stratified random sampling as it is with simple random sampling, but suggest that sample placement may have more of an effect on estimates of accuracy than sampling method alone. Numéro de notice : A2003-031 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.14358/PERS.69.3.289 En ligne : https://doi.org/10.14358/PERS.69.3.289 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22328 [article]