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Impact of lidar nominal post-spacing on DEM accuracy and flood zone delineation / G.T. Raber in Photogrammetric Engineering & Remote Sensing, PERS, vol 73 n° 7 (July 2007)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 73 n° 7 (July 2007) . - pp 793 - 804 Titre : Impact of lidar nominal post-spacing on DEM accuracy and flood zone delineation Type de document : Article/Communication Auteurs : G.T. Raber, Auteur ; J.R. Jensen, Auteur Année de publication : 2007 Article en page(s) : pp 793 - 804 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique [Termes IGN] données lidar [Termes IGN] inondation [Termes IGN] lasergrammétrie [Termes IGN] modèle hydrographique [Termes IGN] modèle numérique de terrain [Termes IGN] plan de vol [Termes IGN] précision des données [Termes IGN] précision du positionnement [Termes IGN] prise de vue aérienne [Termes IGN] réseau hydrographique [Termes IGN] semis de points Résumé : (Auteur) Lidar data have become a major source of digital terrain information for use in many applications including hydraulic modeling and flood plane mapping. Based on established relationships between sampling intensity and error, nominal post-spacing likely contributes significantly to the error budget. Post-spacing is also a major cost factor during lidar data collection. This research presents methods for establishing a relationship between nominal post-spacing and its effects on hydraulic modeling for flood zone delineation. Lidar data collected at a low post-spacing (approximately 1 to 2 m) over a piedmont study area in North Carolina was systematically decimated to simulate datasets with sequentially higher post-spacing values. Using extensive first-order ground survey information, the accuracy of each DEM derived from these lidar datasets was assessed and reported. Hydraulic analyses were performed utilizing standard engineering practices and modeling software (HEC-RAS). All input variables were held constant in each model run except for the topographic information from the decimated lidar datasets. The results were compared to a hydraulic analysis performed on the un-decimated reference dataset. The sensitivity of the primary model outputs to the variation in nominal post-spacing is reported. The results indicate that base flood elevation does not statistically change over the post-spacing values tested. Conversely, flood zone boundary mapping was found to be sensitive to variations in post-spacing. Copyright ASPRS Numéro de notice : A2007-313 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.73.7.793 En ligne : http://dx.doi.org/10.14358/PERS.73.7.793 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28676 [article]

Creation of digital terrain models using an adaptative Lidar vegetation point removal process / G.T. Raber in Photogrammetric Engineering & Remote Sensing, PERS, vol 68 n° 12 (December 2002)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 68 n° 12 (December 2002) . - pp 1307 - 1315 Titre : Creation of digital terrain models using an adaptative Lidar vegetation point removal process Type de document : Article/Communication Auteurs : G.T. Raber, Auteur ; J.R. Jensen, Auteur ; S.R. Schill, Auteur ; K. Schuckman, Auteur Année de publication : 2002 Article en page(s) : pp 1307 - 1315 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] carte de la végétation [Termes IGN] données lidar [Termes IGN] erreur [Termes IGN] lasergrammétrie [Termes IGN] modèle numérique de terrain [Termes IGN] végétation Résumé : (Auteur) Commercial small-footprint lidar remote sensing has become an established tool for the creation of digital terrain models (DTMs). Unfortunately, even ofter the application of lidar vegetation point removal algorithms, vertical DTM error is not uniform and varies according to land cover. This paper presents the results of the application of an adaptive lidar vegetation removal process to a raw lidar dataset of a small area in North Carolina. This process utilized an existing lidar vegetation point removal algorithm in which the parameters were adaptively adjusted based on a vegetation map. The vegetation map was derived through the exclusive use of the lidar dataset, making the process independent of ancillary data. The vertical error and surface form of the resulting DTM were then compared to DTMs created using traditional techniques. The results indicate that the adaptive method produces a superior DTM. Numéro de notice : A2002-299 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : sans En ligne : https://www.asprs.org/wp-content/uploads/pers/2002journal/december/2002_dec_1307 [...] Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=22210 [article]