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A rigorous cylinder-based self-calibration approach for terrestrial laser scanners / Ting On Chan in ISPRS Journal of photogrammetry and remote sensing, vol 99 (January 2015)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 99 (January 2015) . - pp 84 - 99 Titre : A rigorous cylinder-based self-calibration approach for terrestrial laser scanners Type de document : Article/Communication Auteurs : Ting On Chan, Auteur ; Derek D. Lichti, Auteur ; David Belton, Auteur Année de publication : 2015 Article en page(s) : pp 84 - 99 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] étalonnage d'instrument [Termes IGN] étalonnage géométrique [Termes IGN] lasergrammétrie [Termes IGN] télémètre laser terrestre Résumé : (Auteur) Existing self-calibration methods for terrestrial laser scanners are predominantly point-based and plane-based. In this paper, we present a new cylinder-based self-calibration method with its variants for several scanners having different architectures and scanning mechanisms. The method not only increases the flexibility of in situ self-calibration, but also its rigor because of reduced functional dependencies between adjustment parameters. Based on the analysis of linear dependencies between columns of the design matrices for both the cylindrical and planar models, it is shown that using the vertical cylindrical model is advantageous over using the planar model as some high linear dependencies can be avoided. The proposed method and its variants were first applied to two simulated datasets, to compare their effectiveness, and then to three real datasets captured by three different types of scanners are presented: a Faro Focus 3D (a phase-based panoramic scanner); a Velodyne HDL-32E (a pulse-based multi spinning beam scanner); and a Leica ScanStation C10 (a dual operating-mode scanner). The experimental results show that the proposed method can properly estimate the additional parameters with high precision. More importantly, no high correlations were found between the additional parameters and other parameters when the network configuration is strong. The overall results indicate that the proposed calibration method is rigorous and flexible. Numéro de notice : A2014-636 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2014.11.003 En ligne : https://doi.org/10.1016/j.isprsjprs.2014.11.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75062 [article]

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081-2015011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Structural dynamic deflection measurement with range cameras / Xiaojuan Qi in Photogrammetric record, vol 29 n° 145 (March - May 2014)  

Public [article]  inPhotogrammetric record > vol 29 n° 145 (March - May 2014) . - pp 89 - 107 Titre : Structural dynamic deflection measurement with range cameras Type de document : Article/Communication Auteurs : Xiaojuan Qi, Auteur ; Derek D. Lichti, Auteur ; Mamdouh El-Badry, Auteur ; Ting On Chan, Auteur ; et al., Auteur Année de publication : 2014 Article en page(s) : pp 89 - 107 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] déformation d'édifice [Termes IGN] photogrammétrie terrestre [Termes IGN] surveillance d'ouvrage [Termes IGN] télémétrie Résumé : (Auteur) Time-of-flight range cameras offer numerous advantages for the measurement of dynamic phenomena, thanks to their ability to directly measure three-dimensional coordinates of objects at video rates using only one sensor. This paper reports the results of an investigation into the development of a range camera based system for measuring the deflection of reinforced concrete beams subjected to cyclic fatigue loading. New data segmentation methods and reconstruction algorithms have been developed to reconstruct the time-dependent displacement of the beam with sub-millimetre amplitude and millihertz-level frequency precision and accuracy in all three dimensions along the entire beam length. Moreover, sub-millimetre changes in displacement measurements due to stiffness degradation caused by fatigue are also reported. Numéro de notice : A2014-157 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12047 Date de publication en ligne : 21/02/2014 En ligne : https://doi.org/10.1111/phor.12047 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=33062 [article]

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106-2014011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Multi-feature based boresight self-calibration of a terrestrial mobile mapping system / Ting On Chan in ISPRS Journal of photogrammetry and remote sensing, vol 82 (August 2013)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 82 (August 2013) . - pp 112 - 124 Titre : Multi-feature based boresight self-calibration of a terrestrial mobile mapping system Type de document : Article/Communication Auteurs : Ting On Chan, Auteur ; Derek D. Lichti, Auteur ; Craig L. Glennie, Auteur Année de publication : 2013 Article en page(s) : pp 112 - 124 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] angle de visée [Termes IGN] auto-étalonnage [Termes IGN] compensation par moindres carrés [Termes IGN] étalonnage in situ [Termes IGN] ligne de visée [Termes IGN] semis de points [Termes IGN] système de numérisation mobile Résumé : (Auteur) This paper presents a multi-feature based system calibration method for estimating the boresight angles of a land-based mobile mapping system (MMS) comprised of multiple two dimensional (2D) scanners. The method invokes a least-squares adjustment (LSA) to simultaneously estimate several sets of boresight angles for multiple laser scanners incorporated in an MMS as well as the parameters associated with one or more types of geometric features. This is achieved by constraining the groups of feature point clouds captured by multiple runs to fit their corresponding geometric models in such a way that the weighted sum of squares of adjustment residuals is minimized. The method is particularly suitable for in situ calibration because the geometric features involved are commonly occurring structures (e.g. building façades, bridge surfaces, highway signs and hanging power cables) that are usually captured during the actual survey. In addition to using a planar feature model for calibration, a novel and rigorous three-dimensional (3D) catenary curve model is proposed for geometric modelling of hanging cables to augment the calibration. The proposed calibrations were examined with several different combinations of groups of planar and catenary features and the resulting analysis suggests that the in situ calibrations are effective when compared to the manufacturer’s dedicated calibration, with the overall point cloud accuracies for plane fitting being 5.5 cm and 5.4 cm for the vertical and horizontal directions, respectively. It has been successfully demonstrated that the proposed method can be used in a scene having no building façades but only some long hanging cables and horizontal ground surfaces. This is particularly useful for rural areas or inter-city/provincial highways where building façades cannot commonly be captured. Parameter correlations in the calibrations were also addressed. It has also been shown that using catenary features in addition to planar features for the calibration can help de-correlate some parameters and improve the overall accuracy. The in situ nature and the high flexibility of integrating different features of the calibration make the proposed method straightforward for most end-users. Numéro de notice : A2013-424 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2013.04.005 En ligne : https://doi.org/10.1016/j.isprsjprs.2013.04.005 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32562 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
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