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Automatic mapping of forest stands based on three-dimensional point clouds derived from terrestrial laser-scanning / Tim Ritter in Forests, vol 8 n° 8 (August 2017)  

Public [article]  inForests > vol 8 n° 8 (August 2017) Titre : Automatic mapping of forest stands based on three-dimensional point clouds derived from terrestrial laser-scanning Type de document : Article/Communication Auteurs : Tim Ritter, Auteur ; Marcel Schwarz, Auteur ; Andreas Tockner, Auteur ; Friedrich Leisch, Auteur ; Arne Nothdurft, Auteur Année de publication : 2017 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Abies alba [Termes IGN] analyse de groupement [Termes IGN] Autriche [Termes IGN] diamètre à hauteur de poitrine [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] Fagus sylvatica [Termes IGN] inventaire forestier (techniques et méthodes) [Termes IGN] Larix decidua [Termes IGN] peuplement forestier [Termes IGN] Picea abies [Termes IGN] Pinus sylvestris [Termes IGN] Préalpes (Europe) [Termes IGN] semis de points [Vedettes matières IGN] Inventaire forestier Résumé : (Auteur) Mapping of exact tree positions can be regarded as a crucial task of field work associated with forest monitoring, especially on intensive research plots. We propose a two-stage density clustering approach for the automatic mapping of tree positions, and an algorithm for automatic tree diameter estimates based on terrestrial laser-scanning (TLS) point cloud data sampled under limited sighting conditions. We show that our novel approach is able to detect tree positions in a mixed and vertically structured stand with an overall accuracy of 91.6%, and with omission- and commission error of only 5.7% and 2.7% respectively. Moreover, we were able to reproduce the stand’s diameter in breast height (DBH) distribution, and to estimate single trees DBH with a mean average deviation of ±2.90 cm compared with tape measurements as reference. Numéro de notice : A2017-876 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/f8080265 Date de publication en ligne : 25/07/2017 En ligne : https://doi.org/10.3390/f8080265 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91195 [article]

Detection of storm losses in alpine forest areas by different methodical approaches using high-resolution satellite data [pixel-based classification and object-oriented classification] / Marcel Schwarz (2001)

Public contenu dans Observing our environment from space / G. Begni (2002) Titre : Detection of storm losses in alpine forest areas by different methodical approaches using high-resolution satellite data [pixel-based classification and object-oriented classification] Type de document : Article/Communication Auteurs : Marcel Schwarz, Auteur ; C. Steinmeier, Auteur ; Lars T. Waser, Auteur Editeur : Lisse et Amsterdam : Balkema (August Aimé) Année de publication : 2001 Conférence : EARSeL 2001, 21st international symposium, Observing our environment from space : news solutions for a new millennium 14/05/2001 16/05/2001 Paris France Importance : pp 251 - 257 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] Alpes [Termes IGN] analyse comparative [Termes IGN] classification [Termes IGN] dommage matériel [Termes IGN] forêt [Termes IGN] image Ikonos [Termes IGN] image SPOT [Termes IGN] risque naturel [Termes IGN] segmentation d'image [Termes IGN] Suisse [Termes IGN] tempête [Termes IGN] texture d'image Résumé : (Auteur) Based on the detection of storm losses in Swiss alpine forest areas, two different digital classification approaches were compared. In contrast to the pixel based classification we investigated an object-oriented classification procedure. The eCognition software package of Definiens offers this possibility. The comparison was performed for images with different spatial resolution - very high resolution images of IKONOS, and images of SPOT in the sharpened mode. The evaluation of the IKONOS image indicated a significantly higher accuracy for the object-oriented classification approach than for the pixel-based method. The eCognition software handles the high level of detail and the associated high texture better than the pixelbased parallelepiped-algorithm. The quality of the pixel-based approach, which takes into account only the spectral information and some derived data-products is limited for very high resolution images. The classification of the SPOT presented approximately the same results for both methods. Numéro de notice : C2001-031 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Communication DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=64939