Centre de documentation
scientifique

Algebraic method to speed up robust algorithms: example of laser-scanned point clouds / B. Palancz in Survey review, vol 49 n° 357 (December 2017)  

Public [article]  inSurvey review > vol 49 n° 357 (December 2017) . - pp 408 - 418 Titre : Algebraic method to speed up robust algorithms: example of laser-scanned point clouds Type de document : Article/Communication Auteurs : B. Palancz, Auteur ; Joseph L. Awange, Auteur ; T. Lovas, Auteur ; R. Lewis, Auteur ; B. Molnar, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 408 - 418 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] bases de Gröbner [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] méthode du maximum de vraisemblance (estimation) [Termes IGN] Ransac (algorithme) [Termes IGN] reconstruction d'objet [Termes IGN] semis de points [Termes IGN] valeur aberrante Résumé : (auteur) Surface reconstruction from point clouds generated by laser scanning technology has become a fundamental task in many fields of geosciences, such as robotics, computer vision, digital photogrammetry, computational geometry, digital building modelling, forest planning and operational activities. Point clouds produced by laser scanning, however, are limited due to the occurrence of occlusions, multiple reflectance and noise, and off-surface points (outliers), thus necessitating the need for robust fitting techniques. In this contribution, a fast, non-iterative and data invariant algebraic algorithm with constant O(1) complexity that fits planes to point clouds in the total least squares sense using Gaussian-type error distribution is proposed. The maximum likelihood estimator method is used, resulting in a multivariate polynomial system that is solved in an algebraic way. It is shown that for plane fitting when datasets are affected heavily by outliers, the proposed algebraic method can be embedded into the framework of robust methods like the Danish or the RANdom SAmple Consensus methods and computed in parallel to provide rigorous algebraic fitting with significantly reduced running times. Compared to the embedded traditional singular value decomposition and principal component analysis approaches, the performance of the proposed algebraic algorithm demonstrated its efficiency on both synthetic data and real laser-scanned measurements. The evaluation of a symbolic algebraic formula is practically independent of the values of its coefficients; however, the computation of the coefficients depends on the complexity of the data. Since the main advantage of the symbolic solution is its non-requirement of numerical iteration, the data complexity will have weak influence on the speed-up. The novelty of the proposed method is the use of algebraic technique in a robust plane fitting algorithm that could be applied to remote sensing data analysis/delineation/classification. In general, the method could be applied to most plane fitting problems in the geoscience field. Numéro de notice : A2017-755 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/00396265.2016.1183939 En ligne : https://doi.org/10.1080/00396265.2016.1183939 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89109 [article]

Laser scanning in deformation measurements / A. Berenyi in GIM international, vol 23 n° 3 (March 2009)

Public [article]  inGIM international > vol 23 n° 3 (March 2009) . - pp 17 - 21 Titre : Laser scanning in deformation measurements Type de document : Article/Communication Auteurs : A. Berenyi, Auteur ; T. Lovas, Auteur Année de publication : 2009 Article en page(s) : pp 17 - 21 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] auscultation d'ouvrage [Termes IGN] déformation d'édifice [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] Hongrie [Termes IGN] pont [Termes IGN] surveillance d'ouvrage [Termes IGN] télémétrie laser terrestre Résumé : (Auteur) State-of-the-art geodetic and remote sensing techniques can prove their potential through particular engineering applications. Here we discuss load test measurements of bridges over the Danube. Prior to the particular bridge surveying projects, accuracy analysis was carried out in the laboratory. We describe the shortcomings and limitations of remote sensing and propose the joint application of traditional and remote sensing technologies. We also provide recommendations for further applications of laser scanning in deformation measurement of structures. Copyright Reed Business Numéro de notice : A2009-050 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29680 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
061-09031	RAB	Revue	Centre de documentation	En réserve L003	Disponible

The potential of low-end imus for mobile mapping systems / A. Barsi in Revue Française de Photogrammétrie et de Télédétection, n° 185 (Mars 2007)  

Public [article]  inRevue Française de Photogrammétrie et de Télédétection > n° 185 (Mars 2007) . - pp 91 - 94 Titre : The potential of low-end imus for mobile mapping systems Type de document : Article/Communication Auteurs : A. Barsi, Auteur ; T. Lovas, Auteur ; I. Kertesz, Auteur Année de publication : 2007 Conférence : ISPRS 2006, Commission 1 Symposium, From sensors to imagery 03/07/2006 06/07/2006 Champs-sur-Marne [Paris Marne-la-Vallée] France OA ISPRS Archives Article en page(s) : pp 91 - 94 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] acquisition de données [Termes IGN] centrale inertielle [Termes IGN] chaussée [Termes IGN] détection automatique [Termes IGN] filtre de Kalman [Termes IGN] GPS-INS [Termes IGN] Hongrie [Termes IGN] instrument de photogrammétrie [Termes IGN] réseau routier [Termes IGN] système de numérisation mobile Résumé : (Auteur) Due to the decreasing prices of the sensors and equipments, mobile mapping technologies are widely used even in the commercial area (e.g. transportation) in the 21st century. The road networks often cannot cope with the increased traffic load; moreover, the roads in bad condition reduce the overall capacity of a network. Pavement condition is a central aspect of road transportation infrastructure management, and is particularly highlighted in Hungary; the loss in travel time, the damage in vehicles results in significant indignation in society and gives an everyday topic for the actual political life. Scheduling road construction works requires effective monitoring of road conditions and the various components of a particular network have to be classified by quality. This paper introduces a complex road pavement measurement system designed primarily for pothole and crack detection. The system, installed in a vehicle is composed of a navigation unit, image acquisition module and a photogrammetric image-processing subsystem. The navigation unit consists of an integrated GPS/INS system; the trajectory and attitude of the vehicle at the required accuracy is provided by a Kalman filter. All the sensors and a high-speed computer are mounted on a pick-up. The low-end inertial measurement units (IMUs) have continued to improve in the last years, which broadened their application fields. The paper discusses the experimental results of the IMUs. First we compared the performance of two low-end IMUs on various road surfaces (wavy pavement, potholes etc.); secondly we analyzed their impact on the application. The obtained results have proved the potential of these types of sensors for this kind of road engineering applications. Copyright SFPT Numéro de notice : A2007-403 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans En ligne : https://www.isprs.org/proceedings/XXXVI/part1/Papers/PS3-51.pdf Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28766 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
018-07011	RAB	Revue	Centre de documentation	En réserve L003	Disponible