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3D vegetation mapping using small-footprint full-waveform airborne laser scanners / W. Wagner in International Journal of Remote Sensing IJRS, vol 29 n° 5 (March 2008)
[article]
Titre : 3D vegetation mapping using small-footprint full-waveform airborne laser scanners Type de document : Article/Communication Auteurs : W. Wagner, Auteur ; Markus Hollaus, Auteur ; et al., Auteur Année de publication : 2008 Article en page(s) : pp 1433 - 1452 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] carte de la végétation
[Termes IGN] données localisées 3D
[Termes IGN] lidar à retour d'onde complète
[Termes IGN] modèle numérique de terrain
[Termes IGN] rayonnement infrarouge
[Termes IGN] semis de points
[Termes IGN] signal laser
[Termes IGN] télémétrie laser aéroportéRésumé : (Auteur) Small-footprint full-waveform airborne laser scanning (ALS) is a remote sensing technique capable of mapping vegetation in three dimensions with a spatial sampling of about 0.5-2 m in all directions. This is achieved by scanning the laser beam across the Earth's surface and by emitting nanosecond-long infrared pulses with a high frequency of typically 50-150 kHz. The echo signals are digitized during data acquisition for subsequent off-line waveform analysis. In addition to delivering the three-dimensional (3D) coordinates of scattering objects such as leaves or branches, full-waveform laser scanners can be calibrated for measuring the scattering properties of vegetation and terrain surfaces in a quantitative way. As a result, a number of physical observables are obtained, such as the width of the echo pulse and the backscatter cross-section, which is a measure of the electromagnetic energy intercepted and re-radiated by objects. The main aim of this study was to build up an understanding of the scattering characteristics of vegetation and the underlying terrain. It was found that vegetation typically causes a broadening of the backscattered pulse, while the backscatter cross-section is usually smaller for canopy echoes than for terrain echoes. These scattering properties allowed classification of the 3D point cloud into vegetation and non-vegetation echoes with an overall accuracy of 89.9% for a dense natural forest and 93.7% for a baroque garden area. In addition, by removing the vegetation echoes before the filtering process, the quality of the digital terrain model could be improved. Copyright Taylor & Francis Numéro de notice : A2008-082 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160701736398 En ligne : https://doi.org/10.1080/01431160701736398 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29077
in International Journal of Remote Sensing IJRS > vol 29 n° 5 (March 2008) . - pp 1433 - 1452[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-08031 RAB Revue Centre de documentation En réserve L003 Exclu du prêt A method to test differences between additional parameter sets with a case study in terrestrial laser scanner self-calibration stability analysis / Derek D. Lichti in ISPRS Journal of photogrammetry and remote sensing, vol 63 n° 2 (March - April 2008)
[article]
Titre : A method to test differences between additional parameter sets with a case study in terrestrial laser scanner self-calibration stability analysis Type de document : Article/Communication Auteurs : Derek D. Lichti, Auteur Année de publication : 2008 Article en page(s) : pp 169 - 180 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] auto-étalonnage
[Termes IGN] compensation par faisceaux
[Termes IGN] erreur systématique
[Termes IGN] orientation du capteur
[Termes IGN] point d'appui
[Termes IGN] reconstruction d'objet
[Termes IGN] stabilité
[Termes IGN] télémètre laser à balayage
[Termes IGN] télémètre laser terrestre
[Termes IGN] test statistiqueRésumé : (Auteur) This paper presents a new method for quantitatively assessing the impact and therefore the significance of differences between sets of additional parameters used to model systematic sensor errors. Focusing on bundle reconstruction at the sensor, simulation-based techniques have recently been proposed as superior methods to standard parameter-space hypothesis testing. This paper experimentally demonstrates the shortcoming of this approach and proposes an improved method that tests the effect of additional parameter differences on object reconstruction, which is generally of primary interest in photogrammetry. Additionally, the arbitrariness in selecting only one or two object space configurations is overcome with the new method by simulating a large number of randomly-generated but realistic control point networks for sensor orientation and a dense grid of points for object reconstruction. The experimental subject of the paper is a Faro 880 terrestrial laser scanner for which 10 sets of calibration parameters have been captured over a 13-month period. While standard parameter-space hypothesis testing indicates the instrument is not stable over this time, the new procedure shows that this is not true in all instances. Copyright ISPRS Numéro de notice : A2008-114 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2007.08.001 En ligne : https://doi.org/10.1016/j.isprsjprs.2007.08.001 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29109
in ISPRS Journal of photogrammetry and remote sensing > vol 63 n° 2 (March - April 2008) . - pp 169 - 180[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-08021 SL Revue Centre de documentation Revues en salle Disponible
Titre : Analysis of full-waveform Lidar data for classification of urban areas Type de document : Article/Communication Auteurs : Uwe Soergel, Auteur ; Frédéric Bretar, Auteur ; Clément Mallet , Auteur Editeur : International Society for Photogrammetry and Remote Sensing ISPRS Année de publication : 2008 Collection : International Archives of Photogrammetry and Remote Sensing, ISSN 0252-8231 num. 37-B3 Conférence : ISPRS 2008, 21st ISPRS world congress 03/07/2008 11/07/2008 Pékin Chine OA ISPRS Archives Importance : pp 85 - 91 Format : 21 x 30 cm Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] classification par séparateurs à vaste marge
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] impulsion laser
[Termes IGN] lidar à retour d'onde complète
[Termes IGN] milieu urbain
[Termes IGN] semis de points
[Termes IGN] signal lidar
[Termes IGN] traitement du signalRésumé : (auteur) In contrast to conventional airborne multi-echo laser scanner systems, full-waveform (FW) lidar systems are able to record the entire emitted and backscattered signal of each laser pulse. Instead of clouds of individual 3D points, FW devices provide connected 1D profiles of the 3D scene, which contain more detailed and additional information about the structure of the illuminated surfaces. This paper is focused on the analysis of FW data in urban areas. The problem of modelling FW lidar signals is first tackled. The standard method assumes the waveform to be the superposition of signal contributions of each scattering object in such a laser beam, which are approximated by Gaussian distributions. This model is suitable in many cases, especially in vegetated terrain. However, since it is not tailored to urban waveforms, the generalized Gaussian model is selected instead here. Then, a pattern recognition method for urban area classification is proposed. A supervised method using Support Vector Machines is performed on the FW point cloud based on the parameters extracted from the post-processing step. Results show that it is possible to partition urban areas in building, vegetation, natural ground and artificial ground regions with high accuracy using only lidar waveforms. Numéro de notice : C2008-022 Affiliation des auteurs : MATIS+Ext (1993-2011) Thématique : IMAGERIE Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : sans En ligne : https://www.isprs.org/proceedings/XXXVII/congress/3_pdf/13.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=64223 Documents numériques
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Titre : Calibration of a terrestrial laser scanner for engineering geodesy Type de document : Thèse/HDR Auteurs : Thorsten Schulz, Auteur Editeur : Zurich : Institut für Geodäsie und Photogrammetrie IGP - ETH Année de publication : 2008 Collection : IGP Mitteilungen, ISSN 0252-9335 num. 96 Importance : 158 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-906467-71-9 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] angle d'incidence
[Termes IGN] balayage laser
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] erreur instrumentale
[Termes IGN] étalonnage d'instrument
[Termes IGN] semis de points
[Termes IGN] télémètre laser terrestre
[Termes IGN] traitement automatique de donnéesIndex. décimale : 35.10 Acquisition d'images Résumé : (Auteur) For several years now, terrestrial laser scanning has become an additional surveying technique in geodesy. Recent developments have improved several aspects of terrestrial laser scanners, e.g. the data acquisition rate, accuracy, and range. Since such instruments are relatively new and constructed by manufacturers who do not have advanced experience in surveying instruments, investigations are needed to assess the quality of the instrumental characteristics and the acquired data. In this way, manufacturers will understand the needs of geodesists and in turn enable geodesists to provide the necessary support in the development of improvements. This thesis has three objectives, the calibration and investigation of a terrestrial laser scanner, the post-processing of point clouds acquired by laser scanners, and applications of terrestrial laser scanning.
The first objective is a comprehensive calibration and investigation of a specific laser scanner, the Imager 5003 of Zoller+Frohlich GmbH (Germany). The investigation and calibration procedures shall give a general impulse for all users of terrestrial laser scanning regarding instrumental and non-instrumental errors, the assessment of the quality of distance and angle measurements, and the influencing parameters. Laser scanners are a black box instrument that produces a huge number of 3D points in the form of a point cloud in a short time. However, it is the surveyor, who has to assess the reliability and quality of the resulting data. Therefore, the potential and the limitations of laser scanner systems must be identified. This is particularly important when a distance measurement is influenced by several parameters that can bias the data. Since laser scanning is an active surveying method, mostly independent of lighting conditions, distance measurements do not require prisms. Thus, surveying of almost every object is conceivable.
The second objective involves post-processing of the point clouds. Terrestrial laser scanning consists not only of data acquisition, but also processing of the acquired 3D data, which include an intensity value of the reflected laser beam. The point clouds define the objects and the data contains nearly all the information about the objects due to the high sampling interval of laser scanners. To produce the final result, data processing needs to be completed and this can be quiet involving, e.g. registration, data filtering, noise reduction, triangulation, and modeling. The ratio between post-processing and data acquisition can be 10:1 or greater, which means ten (or more) days of post-processing follow one day of data acquisition. This aspect of post-processing applies for both static laser scanning and kinematic laser scanning. The only difference is that kinematic laser scanning requires an unique method of registration and geo-referencing.
The third objective examines the applications of terrestrial laser scanning. Laser scanning can be used in different fields of applications, e.g. industrial metrology, cultural heritage, reverse engineering, and engineering geodesy. Due to the increased requirements regarding accuracy engineering geodesy appears to be a challenging field. Therefore, three different applications are presented which verify the successful use of terrestrial laser scanning in engineering geodesy. The first application involves the field of urban water management. A road surface was scanned to derive catchment areas and water flow directions. The second application covers the field of engineering geology. A tunnel during and after excavation was scanned to characterize rock mass structures and to derive displacement maps of surfaces and object points. Since the first two applications are based on static laser scanning, which means the laser scanner did not change in position and orientation during scanning, the third application is a kinematic one, which means the laser scanner was in motion during scanning. Such kinematic applications are of great interest since the performance of laser scanning can be increased significantly. Tunnels and roads are especially appropriate for kinematic laser scanning. The potential of kinematic laser scanning is tested by moving the laser scanner along a track line. The quality is assessed by scanning reference points.Note de contenu : 1 Introduction
1.1 Terrestrial Laser Scanning
1.2 Motivation
1.3 Outline
2 Components of Terrestrial Laser Scanner
2.1 Distance and Reflectance Measurement System
2.1.1 Electromagnetic Waves
2.1.2 Laser
2.1.3 Direct Time-of-Flight
2.1.4 Amplitude-Modulated Continuous Wave (AMCW)
2.1.5 Frequency-Modulated Continuous Wave (FMCW)
2.1.6 Overview of Distance Measurement Techniques in Terrestrial Laser Scanners
2.1.7 Avalanche Photo Diode (APD)
2.1.8 Reflection Principles
2.1.9 Reflectance Models
2.2 Angle Measurement System
2.2.1 Incremental Encoding
2.2.2 Binary Encoding
2.3 Deflection System
2.3.1 Oscillating Mirror
2.3.2 Rotating Mirror
2.3.3 Overview of Deflection Techniques in Terrestrial Laser Scanners
3 Calibration of Terrestrial Laser Scanner
3.1 Laboratories and Tools for Calibration
3.1.1 Calibration Track Line
3.1.2 Test Field of Control Points
3.1.3 Test Field of Observation Pillars
3.1.4 Electronic Unit for Frequency Measurement
3.1.5 Calibration of Spheres
3.2 Distance Measurement System
3.2.1 Static Mode
3.2.2 Scanning Mode
3.2.3 Long-Term Stability
3.2.4 Frequency Stability
3.3 Angle Measurement System
3.3.1 Horizontal Encoder
3.3.2 Vertical Encoder
3.3.3 Angular Resolution
3.4 Instrumental Errors
3.4.1 Eccentricity of Scan Center
3.4.2 Wobble of Vertical axis
3.4.3 Error of Collimation Axis
3.4.4 Error of Horizontal Axis
3.5 Non-Instrumental Errors
3.5.1 Intensity of Laser Beam
3.5.2 Angle of Incidence
3.5.3 Surface Properties of Materials
3.6 Precision and Accuracy of Terrestrial Laser Scanner Data
3.6.1 Single Point Precision
3.6.2 Accuracy of Modeled Objects (Spheres)
4 Static Laser Scanning
4.1 Data Processing
4.1.1 Blunder Detection
4.1.2 Mixed Pixel
4.1.3 Range/Intensity Crosstalk .
4.1.4 Multipath
4.1.5 Noise Reduction
4.2 Registration
4.2.1 Target-Based Registration
4.2.2 Point Cloud Registration
4.3 Modeling and Visualization
4.3.1 Geometrical Primitives
4.3.2 Triangulation
4.3.3 NURBS
4.3.4 CAD
4.3.5 Rendering and Texture Mapping
5 Kinematic Laser Scanning
5.1 Test Trolley on Calibration Track Line
5.1.1 Relative Position and Orientation
5.1.2 Absolute Position and Orientation
5.2 Rotation Time of Rotating Mirror of Laser Scanner
5.2.1 Direct Method
5.2.2 Indirect Method
5.2.3 Discussion and Comparison
5.3 Position-Fixing Using Total Station
5.3.1 Blunder Detection and Smoothing
5.3.2 Polynomial Interpolation
5.3.3 Regression Line
5.3.4 Kalman Filtering
5.4 Synchronisation
6 Applications of Terrestrial Laser Scanning
6.1 Static Application: Road Surface Analysis
6.1.1 Introduction
6.1.2 Method.
6.1.3 Results
6.2 Static Application: Rock Engineering Applications
6.2.1 Introduction
6.2.2 Method.
6.2.3 Results
6.3 Kinematic Application: Test Tunnel
6.3.1 Introduction
6.3.2 Kinematic Model: Regression Line
6.3.3 Kinematic Model: Kalman Filter
6.3.4 Results
7 Summary
7.1 Conclusions
7.2 OutlookNuméro de notice : 13652 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse étrangère En ligne : http://dx.doi.org/10.3929/ethz-a-005368245 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=62557 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 13652-01 35.10 Livre Centre de documentation En réserve M-103 Disponible CAMPINO, a skeletonization method for point cloud processing / Alexander Bucksch in ISPRS Journal of photogrammetry and remote sensing, vol 63 n° 1 (January - February 2008)
[article]
Titre : CAMPINO, a skeletonization method for point cloud processing Type de document : Article/Communication Auteurs : Alexander Bucksch, Auteur ; R. Linderberg, Auteur Année de publication : 2008 Article en page(s) : pp 115 - 127 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] balayage laser
[Termes IGN] segmentation d'image
[Termes IGN] semis de points
[Termes IGN] squelettisation
[Termes IGN] télémètre laser terrestre
[Termes IGN] traitement géométrique de données
[Termes IGN] végétationRésumé : (Auteur) A new algorithm for deriving skeletons and segmentations from point cloud data in O(n) time is explained in this publication. This skeleton is represented as a graph, which can be embedded into the point cloud. The CAMPINO method, (C)ollapsing (A)nd (M)erging (P)rocedures (IN) (O)ctree-graphs, is based on cycle elimination in a graph as derived from an octree based space division procedure. The algorithm is able to extract the skeleton from point clouds generated from either one or multiple viewpoints. The correspondence between the vertices of the graph and the original points of the point cloud is used to derive an initial segmentation of these points. The principle of the algorithm is demonstrated on a synthetic point cloud consisting of 3 connected tori. Initially this algorithm was developed to obtain skeletons from point clouds representing natural trees, measured with the terrestrial laser scanner IMAGER 5003 of Zoller+Fröhlich. The results show that CAMPINO is able to automatically derive realistic skeletons that fit the original point cloud well and are suited as a basis for e.g. further automatic feature extraction or skeleton-based registration. Copyright ISPRS Numéro de notice : A2008-040 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2007.10.004 En ligne : https://doi.org/10.1016/j.isprsjprs.2007.10.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29035
in ISPRS Journal of photogrammetry and remote sensing > vol 63 n° 1 (January - February 2008) . - pp 115 - 127[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-08011 SL Revue Centre de documentation Revues en salle Disponible Coarse orientation of terrestrial laser scans in urban environments / Claus Brenner in ISPRS Journal of photogrammetry and remote sensing, vol 63 n° 1 (January - February 2008)PermalinkDéveloppement et validation d'une méthode de calcul GPS intégrant des mesures de profils de vapeur d'eau en visée multi-angulaire pour l'altimétrie de haute précision / Pierre Bosser (2008)PermalinkInvestigations of high precision terrestrial laser scanning with emphasis on the development of a robust close-range 3D-laser scanning system / Hans Martin Zogg (2008)PermalinkManaging full waveform Lidar data : a challenging task for the forthcoming years / Frédéric Bretar (2008)PermalinkPermalinkProcessing of Raman lidar measurements for water vapor mixing ratio retrieval / Pierre Bosser (2008)Permalinkvol 63 n° 1 - January - February 2008 - Terrestrial laser scanning (Bulletin de ISPRS Journal of photogrammetry and remote sensing) / Derek D. LichtiPermalinkWater vapour intercomparison effort in the frame of the convective and orographically-induced precipitation study / Rohini Bhawar (2008)PermalinkDevelopment of a simulation model to predict Lidar interception in forested environments / N.R. Goodwin in Remote sensing of environment, vol 111 n° 4 (28/12/2007)PermalinkImportant considerations for cranofacial mapping using laser scanners / Z. Majid in Photogrammetric record, vol 22 n° 120 (December 2007 - February 2008)Permalink