Centre de documentation
scientifique

Pavement marking retroreflectivity estimation and evaluation using mobile Lidar data / Erzhuo Che in Photogrammetric Engineering & Remote Sensing, PERS, vol 85 n° 8 (August 2019)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 85 n° 8 (August 2019) . - pp 573 - 583 Titre : Pavement marking retroreflectivity estimation and evaluation using mobile Lidar data Type de document : Article/Communication Auteurs : Erzhuo Che, Auteur ; Michael J. Olsen, Auteur ; Christopher E. Parrish, Auteur ; Jaehoon Jung, Auteur Année de publication : 2019 Article en page(s) : pp 573 - 583 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] étalonnage radiométrique [Termes IGN] réflectivité [Termes IGN] régression [Termes IGN] semis de points [Termes IGN] signalisation routière Résumé : (Auteur) Pavement markings are produced with retroreflective materials to enhance visibility for motorists, particularly at night. Retroreflectivity evaluation throughout an extensive highway network for maintenance and asset management purposes is a critical, yet challenging task for transportation agencies because visual evaluation can often be subjective and inconsistent, while field measurement can be time-consuming. Mobile Light Detection and Ranging (Lidar) datasets can potentially provide a safe, cost-effective, and reliable method of performing the required evaluation. This paper presents an empirical model for radiometric calibration of Lidar intensity information from the Leica Pegasus:Two system for pavement marking evaluation. The model was developed using dense handheld retroreflectometer measurements and mobile Lidar data collected in a variety of geometric configurations on a test site consisting of various markings with varying degrees of wear. The quantitative accuracy assessment of the proposed radiometric calibration model for estimating retroreflectivity was conducted to another independent dataset collected in different lanes and system configurations. Numéro de notice : A2019-409 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.14358/PERS.85.8.573 Date de publication en ligne : 01/08/2019 En ligne : https://doi.org/10.14358/PERS.85.8.573 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93540 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
105-2019081	SL	Revue	Centre de documentation	Revues en salle	Disponible

Efficient terrestrial laser scan segmentation exploiting data structure / Hamid Mahmoudabadi in ISPRS Journal of photogrammetry and remote sensing, vol 119 (September 2016)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 119 (September 2016) . - pp 135 - 150 Titre : Efficient terrestrial laser scan segmentation exploiting data structure Type de document : Article/Communication Auteurs : Hamid Mahmoudabadi, Auteur ; Michael J. Olsen, Auteur ; Sinisa Todorovic, Auteur Année de publication : 2016 Article en page(s) : pp 135 - 150 Note générale : Bibliogaphie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] colorimétrie [Termes IGN] densité d'information [Termes IGN] intensité lumineuse [Termes IGN] modèle logique de données [Termes IGN] plus proche voisin, algorithme du [Termes IGN] segmentation [Termes IGN] semis de points [Termes IGN] système de coordonnées [Termes IGN] télémétrie laser terrestre Résumé : (Auteur) New technologies such as lidar enable the rapid collection of massive datasets to model a 3D scene as a point cloud. However, while hardware technology continues to advance, processing 3D point clouds into informative models remains complex and time consuming. A common approach to increase processing efficiently is to segment the point cloud into smaller sections. This paper proposes a novel approach for point cloud segmentation using computer vision algorithms to analyze panoramic representations of individual laser scans. These panoramas can be quickly created using an inherent neighborhood structure that is established during the scanning process, which scans at fixed angular increments in a cylindrical or spherical coordinate system. In the proposed approach, a selected image segmentation algorithm is applied on several input layers exploiting this angular structure including laser intensity, range, normal vectors, and color information. These segments are then mapped back to the 3D point cloud so that modeling can be completed more efficiently. This approach does not depend on pre-defined mathematical models and consequently setting parameters for them. Unlike common geometrical point cloud segmentation methods, the proposed method employs the colorimetric and intensity data as another source of information. The proposed algorithm is demonstrated on several datasets encompassing variety of scenes and objects. Results show a very high perceptual (visual) level of segmentation and thereby the feasibility of the proposed algorithm. The proposed method is also more efficient compared to Random Sample Consensus (RANSAC), which is a common approach for point cloud segmentation. Numéro de notice : A2016-781 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2016.05.015 En ligne : https://doi.org/10.1016/j.isprsjprs.2016.05.015 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82477 [article]

Insights on initial perceptions of geomatics by engineering students in their first GIS course / Michael J. Olsen in SaLIS Surveying and land information science, vol 73 n° 2 (November 2014)

Public [article]  inSaLIS Surveying and land information science > vol 73 n° 2 (November 2014) . - pp 71 - 79 Titre : Insights on initial perceptions of geomatics by engineering students in their first GIS course Type de document : Article/Communication Auteurs : Michael J. Olsen, Auteur ; Tracy Arras, Auteur Année de publication : 2014 Article en page(s) : pp 71 - 79 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] compétence [Termes IGN] Etats-Unis [Termes IGN] formation initiale [Termes IGN] métier [Termes IGN] sondage statistique [Termes IGN] système d'information géographique Résumé : (Auteur) There is much discussion in the U.S. about shrinking enrollments in geomatics and the impact of an insufficient workforce of trained professionals. A key reason for this problem is likely that many students are not aware of the possibility of the interesting dynamic careers in geomatics or other geospatial fields. Those that begin to learn about geomatics can be confused by the widespread, interdisciplinary options available within geomatics, and are perhaps unsure about where to obtain a degree and what career options are available. This paper will discuss the results of a questionnaire given to sophomore civil and construction engineering students on both their first and last days of a geospatial information and Geographic Information Systems (GIS) class; the intent of the questionnaire was to evaluate the effectiveness of the course in exciting students about pursuing additional geomatics education. The questionnaire analysis was not meant to be scientific, but was given solely to obtain a general feel of their interests, career focus, and overall technical skills relevant to geomatics. The questionnaire was used by the faculty to identify approaches to improve exposure to geomatics at the undergraduate level. Despite being enrolled in a GIS course, at the beginning of the course many were unaware of what GIS was and few could provide a descriptive definition of geomatics. At the conclusion of the course, students showed a measureable increase in interest in geomatics. Numéro de notice : A2014-668 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75125 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
121-2014021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Educating students for the extensive range of surveying activities / Daniel T. Gillins in SaLIS Surveying and land information science, vol 73 n° 1 (May 2013)

Public [article]  inSaLIS Surveying and land information science > vol 73 n° 1 (May 2013) . - pp 21 - 30 Titre : Educating students for the extensive range of surveying activities Type de document : Article/Communication Auteurs : Daniel T. Gillins, Auteur ; Michael J. Olsen, Auteur ; Robert J. Schultz, Auteur Année de publication : 2013 Article en page(s) : pp 21 - 30 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] apprentissage (cognition) [Termes IGN] enseignement supérieur [Termes IGN] Etats-Unis [Termes IGN] Fédération Internationale des Géomètres [Termes IGN] métier Résumé : (Auteur) Today's surveyors are regularly involved in a wide range of activities and interface with people from multiple disciplines. For example, the International Federation of Surveyors (FIG) defines eleven detailed activities that surveyors may perform in practice, ranging from collecting and managing spatial data to evaluating and displaying spatial information. The extensive range and interdisciplinary nature of these activities makes it challenging to develop a program that educates students on all of the necessary fundamentals of each activity. This paper discusses important concepts of each activity, as defined by FIG, and presents a matrix-based approach for identifying potential educational courses that teach those concepts. The matrix format is helpful for designing a balanced curriculum because it enables visualization of which concepts are taught the most to which are taught the least. As an example of this approach, graduate geomatics courses (laser scanning, digital terrain modeling, photogrammetry, control surveying, least squares adjustments, boundary law, property surveying, global positioning system theory and practice, kinematic positioning and navigation, and geographic information systems (GIS)) from the School of Civil and Construction Engineering at Oregon State University are evaluated in the matrix format. Numéro de notice : A2014-398 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=73871 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
121-2013011	RAB	Revue	Centre de documentation	En réserve L003	Disponible