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Planar-based adaptive down-sampling of point clouds / Yun-Jou Lin in Photogrammetric Engineering & Remote Sensing, PERS, vol 82 n° 12 (December 2016)
[article]
Titre : Planar-based adaptive down-sampling of point clouds Type de document : Article/Communication Auteurs : Yun-Jou Lin, Auteur ; Ronald R Benziger, Auteur ; Ayman Habib, Auteur Année de publication : 2016 Article en page(s) : pp 955 - 966 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] densité des points
[Termes IGN] segmentation
[Termes IGN] semis de points
[Termes IGN] surface plane
[Termes IGN] traitement automatique de données
[Termes IGN] traitement de données localiséesRésumé : (auteur) Derived point clouds from laser scanners and image-based dense-matching techniques usually include tremendous number of points. Processing (e.g., segmenting) such huge dataset is time-consuming and might not be necessary. For example, a planar surface just needs few points to be defined. In contrast, linear/cylindrical and rough features require more points for reliable modeling since during the data acquisition process, only a portion of linear/cylindrical features is present in the point cloud.
This paper introduces an adaptive down-sampling strategy for removing redundant points from high density planar regions while retaining points in planar areas with sparse points and all the points within linear/cylindrical and rough neighborhoods. To demonstrate the feasibility and performance of the proposed procedure, a comparison of segmentation results using original laser and image-based point clouds as well as the adaptively, uniformly, and point-spacing-based down-sampled point clouds are presented while commenting on the computational efficiency and the segmentation quality.Numéro de notice : A2016-984 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.82.12.955 En ligne : https://doi.org/10.14358/PERS.82.12.955 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83700
in Photogrammetric Engineering & Remote Sensing, PERS > vol 82 n° 12 (December 2016) . - pp 955 - 966[article]Potentialités de l’outil LiDAR pour cartographier les vestiges de la Grande Guerre en milieu intra-forestier (bois des Caures, forêt domaniale de Verdun, Meuse) / Rémi de Matos Machado in EchoGeo, n° 38 (octobre - décembre 2016)
[article]
Titre : Potentialités de l’outil LiDAR pour cartographier les vestiges de la Grande Guerre en milieu intra-forestier (bois des Caures, forêt domaniale de Verdun, Meuse) Type de document : Article/Communication Auteurs : Rémi de Matos Machado, Auteur ; Jean-Paul Amat, Auteur ; Gilles Arnaud-Fassetta, Auteur ; François Bétard, Auteur Année de publication : 2016 Article en page(s) : pp Note générale : bibliographie Langues : Français (fre) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] carte militaire
[Termes IGN] forêt domaniale
[Termes IGN] fortification
[Termes IGN] Meuse (55)
[Termes IGN] utilisateur militaire
[Termes IGN] VerdunRésumé : (auteur) Cent ans après la Grande Guerre, les traces des champs de bataille restent présentes dans les paysages du Nord-Est de la France. En 2013, une prospection par LiDAR aéroporté de la forêt domaniale de Verdun a mis en évidence sous forme d’images 3-D à haute résolution les vestiges de guerre masqués par le manteau forestier. Cette étude explore les potentialités de l’outil LiDAR pour l’analyse et la cartographie des témoins des aménagements militaires dans le bois des Caures (forêt domaniale de Verdun), lieu des premiers combats de la bataille de Verdun (1916). Le traitement d’images combiné à l’analyse de terrain permet d’établir une typologie et une cartographie inédites de la diversité des vestiges, abris et fossés, et de l’organisation du champ de bataille. Numéro de notice : A2016-947 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.4000/echogeo.14791 En ligne : https://doi.org/10.4000/echogeo.14791 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83439
in EchoGeo > n° 38 (octobre - décembre 2016) . - pp[article]Rigorous strip adjustment of UAV-based laserscanning data including time-dependent correction of trajectory errors / Philipp Glira in Photogrammetric Engineering & Remote Sensing, PERS, vol 82 n° 12 (December 2016)
[article]
Titre : Rigorous strip adjustment of UAV-based laserscanning data including time-dependent correction of trajectory errors Type de document : Article/Communication Auteurs : Philipp Glira, Auteur ; Norbert Pfeifer, Auteur ; Gottfried Mandlburger, Auteur Année de publication : 2016 Article en page(s) : pp 945 - 954 Note générale : biblographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] compensation
[Termes IGN] drone
[Termes IGN] erreur systématique
[Termes IGN] espace-temps
[Termes IGN] étalonnage de capteur (imagerie)
[Termes IGN] orientation du capteur
[Termes IGN] paramètre de temps
[Termes IGN] semis de pointsRésumé : (auteur) A new generation of laser scanners mounted on Unmanned Aerial Vehicles (UAVs) have the potential to provide high-quality point clouds of comparatively small areas (a few hectares). The high maneuverability of the UAVs, a typically large field of view of the laser scanners, and a comparatively small measurement range lead to point clouds with very high point density, less occlusions, and low measurement noise. However, due to the limited payload of UAVs, lightweight navigation sensors with a moderate level of accuracy are used to estimate the platform's trajectory. As a consequence, the georeferencing quality of the point clouds is usually sub-optimal; for this, strip adjustment can be performed. The main goal of strip adjustment is to simultaneously optimize the relative and absolute orientation of the strip-wise collected point clouds. This is done by fully re-calibrating the laser scanning system and by correcting systematic measurement errors of the trajectory. In this paper, we extend our previous work on the topic of strip adjustment by the estimation of time-dependent trajectory errors. The errors are thereby modelled by natural cubic splines with constant segment length in time domain. First results confirm the suitability of this flexible correction model by reducing the relative and absolute strip discrepancies to 1.38 cm and 1.65 cm, respectively. Numéro de notice : A2016-983 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.82.12.945 En ligne : https://doi.org/10.14358/PERS.82.12.945 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83699
in Photogrammetric Engineering & Remote Sensing, PERS > vol 82 n° 12 (December 2016) . - pp 945 - 954[article]Statistical inference for forest structural diversity indices using airborne laser scanning data and the k-Nearest Neighbors technique / Matteo Mura in Remote sensing of environment, vol 186 (1 December 2016)
[article]
Titre : Statistical inference for forest structural diversity indices using airborne laser scanning data and the k-Nearest Neighbors technique Type de document : Article/Communication Auteurs : Matteo Mura, Auteur ; Ronald E. McRoberts, Auteur ; Gherardo Chirici, Auteur ; Marco Marchetti, Auteur Année de publication : 2016 Article en page(s) : pp 678 - 686 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] classification barycentrique
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] indice de diversité
[Termes IGN] inférence statistique
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] Italie
[Termes IGN] optimisation (mathématiques)
[Termes IGN] structure d'un peuplement forestierRésumé : (auteur) Forest structural diversity plays a major role for forest management, conservation and restoration and is recognized as a fundamental aspect of forest biodiversity. The assessment, maintenance and restoration of a diversified forest structure have become major foci in the effort to preserve forest ecosystems from loss of biological diversity. However, the assessment of forest biodiversity is difficult because it involves multiple components and is characterized using multiple variables. The objective of the study was to develop a methodological approach for predicting, mapping, and constructing a statistical inference for a multiple-variable index of forest structural diversity. The method included three key components: (i) use of the k-Nearest Neighbors (k-NN) technique, field plot data, and airborne laser scanning metrics to predict multiple forest structural diversity variables simultaneously, (ii) incorporation of multiple diversity variable predictions into a single index, and (iii) construction of a statistically rigorous inference for the population mean of the index. Three structural diversity variables were selected to illustrate the method: growing stock volume and the standard deviations of tree diameter at breast-height and tree height. Optimization of the k-NN technique produced mean relative deviations less in absolute value than 0.04 for predictions for each of the three structural diversity variables, R2 values between 0.50 and 0.66 which were in the range of values reported in the literature, and a confidence interval for the population mean of the index whose half-width was approximately 5% of the mean. Finally, the spatial pattern depicted in the resulting map of forest structural diversity for the study area contributed to validating the proposed method. Numéro de notice : A2016-769 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2016.09.010 En ligne : http://dx.doi.org/10.1016/j.rse.2016.09.010 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82419
in Remote sensing of environment > vol 186 (1 December 2016) . - pp 678 - 686[article]Systematic effects in laser scanning and visualization by confidence regions / Karl Rudolf Koch in Journal of applied geodesy, vol 10 n° 4 (December 2016)
[article]
Titre : Systematic effects in laser scanning and visualization by confidence regions Type de document : Article/Communication Auteurs : Karl Rudolf Koch, Auteur ; Jan Martin Brockmann, Auteur Année de publication : 2016 Article en page(s) : pp 247 – 257 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] carte de confiance
[Termes IGN] covariance
[Termes IGN] densité de probabilité
[Termes IGN] distribution de Gauss
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] ellipsoïde (géodésie)
[Termes IGN] itération
[Termes IGN] matrice de covariance
[Termes IGN] mesure géométrique
[Termes IGN] méthode de Monte-Carlo
[Termes IGN] série temporelle
[Termes IGN] visualisationRésumé : (auteur) A new method for dealing with systematic effects in laser scanning and visualizing them by confidence regions is derived. The standard deviations of the systematic effects are obtained by repeatedly measuring three-dimensional coordinates by the laser scanner. In addition, autocovariance and cross-covariance functions are computed by the repeated measurements and give the correlations of the systematic effects. The normal distribution for the measurements and the multivariate uniform distribution for the systematic effects are applied to generate random variates for the measurements and random variates for the measurements plus systematic effects. Monte Carlo estimates of the expectations and the covariance matrix of the measurements with systematic effects are computed. The densities for the confidence ellipsoid for the measurements and the confidence region for the measurements with systematic effects are obtained by relative frequencies. They only depend on the size of the rectangular volume elements for which the densities are determined. The problem of sorting the densities is solved by sorting distances together with the densities. This allows a visualization of the confidence ellipsoid for the measurements and the confidence region for the measurements with systematic effects. Numéro de notice : A2016-975 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1515/jag-2016-0012 En ligne : https://doi.org/10.1515/jag-2016-0012 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83682
in Journal of applied geodesy > vol 10 n° 4 (December 2016) . - pp 247 – 257[article]Effective number of layers: A new measure for quantifying three-dimensional stand structure based on sampling with terrestrial LiDAR / Martin Ehbrecht in Forest ecology and management, vol 380 (15 november 2016)PermalinkLocalization of a mobile laser scanner via dimensional reduction / Ville V. Lehtola, in ISPRS Journal of photogrammetry and remote sensing, vol 121 (November 2016)PermalinkNon-rigid registration of 3D point clouds under isometric deformation / Xuming Ge in ISPRS Journal of photogrammetry and remote sensing, vol 121 (November 2016)PermalinkRelevé topographique des environnements urbains [article originellement paru dans le numéro mai/juin 2016 de la revue italienne GEOMedia] / Luigi Colombo in Géomatique expert, n° 113 (novembre - décembre 2016)PermalinkThe weight matrix determination of systematic bias calibration for a laser altimeter / Ma Yue in Photogrammetric Engineering & Remote Sensing, PERS, vol 82 n° 11 (November 2016)PermalinkAccuracy of tree geometric parameters depending on the LiDAR data density / Edyta Hadas in European journal of remote sensing, vol 49 n° 1 (2016)PermalinkAn intensity recovery algorithm (IRA) for minimizing the edge effect of LIDAR data / Fabiane Bordin in European journal of remote sensing, vol 49 n° 1 (2016)PermalinkEffect of flying altitude, scanning angle and scanning mode on the accuracy of ALS based forest inventory / Juha Keränen in International journal of applied Earth observation and geoinformation, vol 52 (October 2016)PermalinkEffects of forest structure and airborne laser scanning point cloud density on 3D delineation of individual tree crowns / Kaja Kandare in European journal of remote sensing, vol 49 n° 1 (2016)PermalinkInterurban visibility diagnosis from point clouds / Oscar Iglesias in European journal of remote sensing, vol 49 n° 1 (2016)Permalink