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Towards the empirical determination of correlations in terrestrial laser scanner range observations and the comparison of the correlation structure of different scanners / Berit Schmitz in ISPRS Journal of photogrammetry and remote sensing, Vol 182 (December 2021)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > Vol 182 (December 2021) . - pp 228 - 241 Titre : Towards the empirical determination of correlations in terrestrial laser scanner range observations and the comparison of the correlation structure of different scanners Type de document : Article/Communication Auteurs : Berit Schmitz, Auteur ; Heiner Kulhmann, Auteur ; Christoph Holst, Auteur Année de publication : 2021 Article en page(s) : pp 228 - 241 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] angle d'incidence [Termes IGN] anisotropie [Termes IGN] corrélation automatique de points homologues [Termes IGN] distance euclidienne [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] matrice de covariance [Termes IGN] modèle stochastique [Termes IGN] semis de points [Termes IGN] télémétrie laser terrestre Résumé : (auteur) The determination of a fully populated variance-covariance matrix (VCM) of a point cloud acquired with a terrestrial laser scanner (TLS) is not straightforward as physical correlations between TLS observations are not sufficiently known. Ignoring correlations leads to biased estimates, wrong modeling of surfaces, or the misinterpretation of geometric changes. For this reason, this study aims at progressing the empirical determination of correlations in TLS range observations by investigating short-scale correlations (mm to cm) of TLS rangefinders. Therefore, two methods are proposed to determine spatial correlations between TLS range observations. Both methods are evaluated for simulated laser scans, and then applied to empirical data of four different terrestrial laser scanners. The results demonstrate that short-scale correlations exist, and it is possible to quantify the relevant parameters to fill the VCM. It also shows that the correlation differs between the scanners and with the distance. Furthermore, we analyze the change of the correlation length with changing scanning configurations such as distance, incidence angle, and reflectivity with the result that this must be considered while applying the aforementioned methods to point clouds of large objects. All in all, this study trustfully quantifies physical short-scale correlations yielding from the rangefinder and suggests a guideline to apply this to point clouds of large objects. Numéro de notice : A2021-853 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2021.10.012 Date de publication en ligne : 10/11/2021 En ligne : https://doi.org/10.1016/j.isprsjprs.2021.10.012 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99043 [article]

Exemplaires(3)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
081-2021121	SL	Revue	Centre de documentation	Revues en salle	Disponible
081-2021123	DEP-RECP	Revue	LASTIG	Dépôt en unité	Exclu du prêt
081-2021122	DEP-RECF	Revue	Nancy	Dépôt en unité	Exclu du prêt

Deformation analysis of a reference wall towards the uncertainty investigation of terrestrial laser scanners / Berit Schmitz in Journal of applied geodesy, vol 15 n° 3 (July 2021)  

Public [article]  inJournal of applied geodesy > vol 15 n° 3 (July 2021) . - pp 189-206 Titre : Deformation analysis of a reference wall towards the uncertainty investigation of terrestrial laser scanners Type de document : Article/Communication Auteurs : Berit Schmitz, Auteur ; Heiner Kuhlmann, Auteur ; Christoph Holst, Auteur Année de publication : 2021 Article en page(s) : pp 189-206 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] déformation d'édifice [Termes IGN] déformation géométrique [Termes IGN] données laser [Termes IGN] incertitude géométrique [Termes IGN] matrice de covariance [Termes IGN] modèle de déformation tectonique [Termes IGN] modèle stochastique [Termes IGN] mur [Termes IGN] qualité des données [Termes IGN] tachéomètre électronique [Termes IGN] télémètre laser terrestre Résumé : (Auteur) The perfect knowledge about the scanned object’s geometry is essential for the empirical analysis of the stochastic properties of terrestrial laser scanners (TLSs). The Bonn reference wall is intended to be used as a reference for TLS quality investigations. Therefore, it is necessary to know the geometry of the wall at each time of scanning to avoid the misinterpretation of possible movements as systematic effects in the scanner. For this reason, we investigate the stability of the Bonn reference wall in this study. This includes the definition of a geodetic datum, the quantification of displacements, and the establishment of a suited deformation model. Since we discover a movement of about 1 mm within one day and up to 7 mm over the year, it is necessary to establish a cause-response deformation model to correct the wall movements in the scans. This study proposes two dynamic deformation models to compensate for the movements of the wall within one day and within a year. Our results show that it is better to measure the initial geometry of the wall each day since 89 % of the relative movements can be reduced to a maximum of 0.25 mm with a standard deviation of 0.16 mm (0.23 mm without modeling). If the shape is not initially known each day, the standard deviation of the displacements can be reduced from 1.10 mm to 0.61 mm, but the largest residuals still amount up to 2.5 mm, which is not sufficient for stochastic TLS investigations. Numéro de notice : A2021-467 Affiliation des auteurs : non IGN Thématique : IMAGERIE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1515/jag-2020-0025 Date de publication en ligne : 25/03/2021 En ligne : https://doi.org/10.1515/jag-2020-0025 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98103 [article]