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Postprocessing synchronization of a laser scanning system aboard a UAV / Marcela do Valle Machado in Photogrammetric Engineering & Remote Sensing, PERS, vol 85 n° 10 (October 2019)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 85 n° 10 (October 2019) . - pp 753 - 763 Titre : Postprocessing synchronization of a laser scanning system aboard a UAV Type de document : Article/Communication Auteurs : Marcela do Valle Machado, Auteur ; Antonio Maria Garcia Tommaselli, Auteur ; Fernanda Magri Torres, Auteur ; Mariana Batista Campos, Auteur Année de publication : 2019 Article en page(s) : pp 753 - 763 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] décalage d'horloge [Termes IGN] données altimétriques [Termes IGN] données lidar [Termes IGN] image captée par drone [Termes IGN] méthode des moindres carrés [Termes IGN] positionnement inertiel [Termes IGN] post-traitement [Termes IGN] précision altimétrique [Termes IGN] semis de points [Termes IGN] signal GNSS [Termes IGN] synchronisation [Termes IGN] télémétrie laser aéroporté [Termes IGN] trajectoire (véhicule non spatial) Résumé : (Auteur) Synchronization of airborne laser scanning devices is a critical process that directly affects data accuracy. This process can be more challenging with low-cost airborne laser scanning (ALS) systems because some device connections from off-the-shelf sensors are less stable. An alternative to synchronization is performing a postprocessing clock correction. This article presents a technique for postprocessing synchronization (off-line) that estimates clock differences based on the correlation between the signals from the global navigation satellite system (GNSS) trajectory and the light detection and ranging (lidar) range, followed by refinement with a least-squares method. The correlation between signals was automatically estimated considering the planned flight maneuvers, in a flat terrain, to produce altimetric trajectory variations. Experiments were performed with an Ibeo LUX laser unit integrated with a NovAtel SPAN-IGM-S1 inertial navigation system that was transported by an unmanned aerial vehicle (UAV). The planimetric and altimetric accuracies of the point cloud obtained with the proposed postprocessing synchronization technique were 28 cm and 10 cm, respectively, at a flight height of 35 m. Numéro de notice : A2019-523 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.14358/PERS.85.10.753 Date de publication en ligne : 01/10/2019 En ligne : https://doi.org/10.14358/PERS.85.10.753 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93994 [article]

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105-2019101	SL	Revue	Centre de documentation	Revues en salle	Disponible

Geometric model and assessment of a dual‐fisheye imaging system / Mariana Batista Campos in Photogrammetric record, vol 33 n° 162 (June 2018)  

Public [article]  inPhotogrammetric record > vol 33 n° 162 (June 2018) . - pp 243 - 263 Titre : Geometric model and assessment of a dual‐fisheye imaging system Type de document : Article/Communication Auteurs : Mariana Batista Campos, Auteur ; Antonio Maria Garcia Tommaselli, Auteur ; José Marcato, Auteur ; Eija Honkavaara, Auteur Année de publication : 2018 Article en page(s) : pp 243 - 263 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] chambre panoramique [Termes IGN] compensation par faisceaux [Termes IGN] élément d'orientation interne [Termes IGN] étalonnage de chambre métrique [Termes IGN] lentille [Termes IGN] panorama sphérique Résumé : (Auteur) This paper presents a technique for the calibration of a 360° dual imaging system (Ricoh Theta S) composed of two cameras with fisheye lenses specially mounted in a common structure. The experiments are based on calibration with a bundle adjustment using the equidistant fisheye lens model and relative orientation stability constraints, such as distance, base elements and rotation matrix between individual cameras’ coordinate systems. As a result, an equidistant mathematical model using the Conrady–Brown lens distortion model was shown to be suitable for estimating the interior and relative orientation parameters of the Ricoh Theta S. The main contribution presented in this work is a simultaneous bundle adjustment approach with stability constraints on base elements and rotation matrix angles, which achieved accuracies comparable with conventional photogrammetric calibration with perspective cameras. Numéro de notice : A2018-225 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1111/phor.12240 Date de publication en ligne : 15/05/2018 En ligne : https://doi.org/10.1111/phor.12240 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90046 [article]

Automatic shadow detection in aerial and terrestrial images / Vander Luis de Souza Freitas in Boletim de Ciências Geodésicas, vol 23 n° 4 (oct - dec 2017)    

Public [article]  inBoletim de Ciências Geodésicas > vol 23 n° 4 (oct - dec 2017) . - pp 578 - 590 Titre : Automatic shadow detection in aerial and terrestrial images Type de document : Article/Communication Auteurs : Vander Luis de Souza Freitas, Auteur ; Barbara Maximino da Fonseca Reis, Auteur ; Antonio Maria Garcia Tommaselli, Auteur Année de publication : 2017 Article en page(s) : pp 578 - 590 Note générale : bibliographie Langues : Portugais (por) Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] détection d'ombre [Termes IGN] image aérienne [Termes IGN] image terrestre Résumé : (auteur) Shadows exist in almost all aerial and outdoor images, and they can be useful for estimating Sun position estimation or measuring object size. On the other hand, they represent a problem in processes such as object detection/recognition, image matching, etc., because they may be confused with dark objects and change the image radiometric properties. We address this problem on aerial and outdoor color images in this work. We use a filter to find low intensities as a first step. For outdoor color images, we analyze spectrum ratio properties to refine the detection, and the results are assessed with a dataset containing ground truth. For the aerial case we validate the detections depending of the hue component of pixels. This stage takes into account that, in deep shadows, most pixels have blue or violet wavelengths because of an atmospheric scattering effect. Numéro de notice : A2017-757 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1590/S1982-21702017000400038 En ligne : http://dx.doi.org/10.1590/S1982-21702017000400038 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89112 [article]

Documents numériques

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Automatic measurement of control points for aerial image orientation / Adilson Berveglieri in Photogrammetric record, vol 32 n° 158 (June - july 2017)  

Public [article]  inPhotogrammetric record > vol 32 n° 158 (June - july 2017) . - pp 141 - 159 Titre : Automatic measurement of control points for aerial image orientation Type de document : Article/Communication Auteurs : Adilson Berveglieri, Auteur ; Antonio Maria Garcia Tommaselli, Auteur Année de publication : 2017 Article en page(s) : pp 141 - 159 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] appariement d'images [Termes IGN] calcul automatique [Termes IGN] compensation par bloc [Termes IGN] image aérienne [Termes IGN] image terrestre [Termes IGN] objectif grand angulaire [Termes IGN] orientation d'image [Termes IGN] point d'appui [Termes IGN] précision des mesures Résumé : (Auteur) This paper presents an automatic workflow for measuring natural ground control points (GCPs) in aerial images. The approach is based on the acquisition of multi-scale fisheye vertical terrestrial images over distinguishable areas to automatically generate georeferenced image patches. These are matched with aerial images using correspondence techniques and then used as ground control. The technique was assessed using a bundle block adjustment, indicating an accuracy based on check points of approximately 1/5 of the ground sample distance (GSD) in planimetry and 1 GSD in elevation. Automatic GCP measurements thus improved the final accuracy in comparison with manual measurement. Numéro de notice : A2017-362 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12190 En ligne : http:dx.doi.org/10.1111/phor.12190 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85773 [article]

Geometric calibration of a hyperspectral frame camera / Raquel A. de Oliveira in Photogrammetric record, vol 31 n° 155 (September - November 2016)  

Public [article]  inPhotogrammetric record > vol 31 n° 155 (September - November 2016) . - pp 325 - 347 Titre : Geometric calibration of a hyperspectral frame camera Type de document : Article/Communication Auteurs : Raquel A. de Oliveira, Auteur ; Antonio Maria Garcia Tommaselli, Auteur ; Eija Honkavaara, Auteur Année de publication : 2016 Article en page(s) : pp 325 - 347 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] étalonnage de capteur (imagerie) [Termes IGN] étalonnage géométrique [Termes IGN] filtre adaptatif [Termes IGN] image hyperspectrale [Termes IGN] interféromètre Résumé : (Auteur) Recently, miniaturised hyperspectral sensors operable from small unmanned airborne vehicle platforms have entered the market. The emerging hyperspectral imaging technologies, based on frame cameras and tuneable filters, are attractive alternatives to hyperspectral pushbroom sensors. This paper addresses the geometric calibration process of a hyperspectral frame camera based on a Fabry–Perot interferometer. However, the addition of more optical elements in front of the image sensor can affect the parameters related to the internal geometry of the camera, and a deficiency in knowledge regarding these parameters can have a critical effect on the accuracy of 3D measurements in photogrammetric applications. The experiments focused on assessing the self-calibrating bundle adjustment to verify the behaviour of the interior parameters, considering different spectral bands. The results indicated that the applied self-calibration method can accurately characterise the interior parameters of this camera and that one set of parameters is required for each internal sensor. Numéro de notice : A2016-724 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12153 Date de publication en ligne : 24/08/2016 En ligne : https://doi.org/10.1111/phor.12153 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82256 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
106-2016031	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Locating control points in aerial images with a multi-scale approach based on terrestrial image patches / Adilson Berveglieri in Photogrammetric record, vol 30 n° 149 (March - May 2015)  

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Exterior orientation of hyperspectral frame images collected with UAV for forest applications / Adilson Berveglieri (2015)  

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Exterior orientation of CBERS-2B imagery using multi-feature control and orbital data / José Marcato in ISPRS Journal of photogrammetry and remote sensing, vol 79 (May 2013)  

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A semi-automatic method for indirect orientation of aerial images using ground control lines extracted from airborne laser scanner data / D. Rodrigues Dos Santos in Revue Française de Photogrammétrie et de Télédétection, n° 198 - 199 (Septembre 2012)  

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The influence of subpixel measurement on digital camera calibration / Mauricio Galo in Revue Française de Photogrammétrie et de Télédétection, n° 198 - 199 (Septembre 2012)  

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Determination of the indirect orientation of orbital pushbroom images using control straight lines / Antonio Maria Garcia Tommaselli in Photogrammetric record, vol 25 n° 130 (June - August 2010)  

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A photogrammetric method for single image orientation and measurement / Antonio Maria Garcia Tommaselli in Photogrammetric Engineering & Remote Sensing, PERS, vol 71 n° 6 (June 2005)  

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