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Determining optimal photogrammetric adjustment of images obtained from a fixed-wing UAV / Karolina Pargiela in Photogrammetric record, Vol 36 n° 175 (September 2021)
Titre : Determining optimal photogrammetric adjustment of images obtained from a fixed-wing UAV Type de document : Article/Communication Auteurs : Karolina Pargiela, Auteur ; Antoni Rzonca, Auteur Année de publication : 2021 Article en page(s) : pp 285 - 302 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] acquisition d'images
[Termes IGN] chevauchement
[Termes IGN] compensation par faisceaux
[Termes IGN] image captée par drone
[Termes IGN] obturateur
[Termes IGN] point d'appui
[Termes IGN] Pologne
[Termes IGN] positionnement cinématique en temps réel
[Termes IGN] structure-from-motion
[Termes IGN] système de numérisation mobileRésumé : (auteur) Photogrammetry with unmanned aerial vehicles (UAVs) has become a source of data with extensive applications. The accuracy is of utmost significance, yet the intention is also to find the best possible solutions for data acquisition in economic terms. The objective of the research was the analysis of various variants of the bundle block adjustment. The analysis concerns data which is diversified with respect to the type of shutter (rolling/global), the measurement of external orientation elements, the overlap and the number of ground control points (GCPs). Numéro de notice : A2021-691 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/phor.12377 Date de publication en ligne : 07/08/2021 En ligne : https://doi.org/10.1111/phor.12377 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98487
in Photogrammetric record > Vol 36 n° 175 (September 2021) . - pp 285 - 302[article]
Titre : Optimising drone flight planning for measuring horticultural tree crop structure Type de document : Article/Communication Auteurs : Yu-Hsuan Tu, Auteur ; Stuart Phinn, Auteur ; Kasper Johansen, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : pp 83 - 96 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] correction d'image
[Termes IGN] détection d'arbres
[Termes IGN] distorsion d'image
[Termes IGN] étalonnage de chambre métrique
[Termes IGN] horticulture
[Termes IGN] image captée par drone
[Termes IGN] MicMac
[Termes IGN] obturateur
[Termes IGN] photogrammétrie aérienne
[Termes IGN] plan de vol
[Termes IGN] point d'appui
[Termes IGN] qualité d'image
[Termes IGN] Queensland (Australie)
[Termes IGN] semis de pointsRésumé : (Auteur) In recent times, multi-spectral drone imagery has proved to be a useful tool for measuring tree crop canopy structure. In this context, establishing the most appropriate flight planning variable settings is an essential consideration due to their controls on the quality of the imagery and derived maps of tree and crop biophysical properties. During flight planning, variables including flight altitude, image overlap, flying direction, flying speed and solar elevation, require careful consideration in order to produce the most suitable drone imagery. Previous studies have assessed the influence of individual variables on image quality, but the interaction of multiple variables has yet to be examined. This study assesses the influence of several flight variables on measures of data quality in each processing step, i.e. photo alignment, point cloud densification, 3D model building, and ortho-mosaicking. The analysis produced a drone flight planning and image processing workflow that delivers accurate measurements of tree crops, including the tie point quality, densified point cloud density, and the measurement accuracy of height and plant projective cover derived from individual trees within a commercial avocado orchard. Results showed that flying along the hedgerow, at high solar elevation and with low image pitch angles improved the data quality. Optimal flying speed needs to be set to achieve the required forward overlap. The impacts of each image acquisition variable are discussed in detail and protocols for flight planning optimisation for three scenarios with different drone settings are suggested. Establishing protocols that deliver optimal image acquisitions for the collection of drone data over horticultural tree crops, will create greater confidence in the accuracy of subsequent algorithms and resultant maps of biophysical properties. Numéro de notice : A2020-044 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2019.12.006 Date de publication en ligne : 18/12/2019 En ligne : https://doi.org/10.1016/j.isprsjprs.2019.12.006 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94524
in ISPRS Journal of photogrammetry and remote sensing > vol 160 (February 2020) . - pp 83 - 96[article]Exemplaires(3)
Code-barres Cote Support Localisation Section Disponibilité 081-2020021 RAB Revue Centre de documentation En réserve L003 Disponible 081-2020023 DEP-RECP Revue LASTIG Dépôt en unité Exclu du prêt 081-2020022 DEP-RECF Revue Nancy Dépôt en unité Exclu du prêt
Titre : A two-step approach for the correction of rolling shutter distortion in UAV photogrammetry Type de document : Article/Communication Auteurs : Yilin Zhou Année de publication : 2020 Projets : 1-Pas de projet / Article en page(s) : pp 51 - 66 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] capteur aérien
[Termes IGN] compensation par faisceaux
[Termes IGN] correction
[Termes IGN] création de zone intermédiaire
[Termes IGN] distorsion d'image
[Termes IGN] étalonnage en vol
[Termes IGN] image captée par drone
[Termes IGN] MicMac
[Termes IGN] obturateur
[Termes IGN] photogrammétrie aérienneRésumé : (Auteur) The use of consumer grade unmanned aerial vehicles (UAV) is becoming more and more ubiquitous in photogrammetric applications. A large proportion of consumer grade UAVs are equipped with CMOS image sensor and rolling shutter. When imaging with a rolling shutter camera, the image sensor is exposed line by line, which can introduce additional distortions in image space since the UAV navigates at a relatively high speed during aerial acquisitions. In this paper, we propose (1) an approach to calibrate the readout time of rolling shutter camera, (2) a two-step method to correct the image distortion introduced by this effect. The two-step method makes assumption that during exposure, the change of camera orientation is negligible with respect to the change of camera position, which is often the case when camera is fixed on a stabilized mount. Firstly, the camera velocity is estimated from the results of an initial bundle block adjustment; then, one camera pose per scan-line of the image sensor is recovered and image observations are corrected. To evaluate the performance of the proposed method, four datasets of block and corridor configurations are acquired with the DJI Mavic 2 Pro and its original Hasselbald L1D-20c camera. The proposed method is implemented in MicMac, a free, open-source photogrammetric software; comparisons are carried out with other two mainstream software, AgiSoft MetaShape and Pix4D, which also have the functionality of rolling shutter effect correction. For block configuration datasets, the three software give comparable results. AgiSoft Metashape and Pix4D are sensitive to the flight configuration and encounter difficulties when processing datasets in corridor configurations. The proposed method shows good robustness both in block and corridor configurations, and is the only method that works in corridor configuration. After the application of the rolling shutter effect correction, the 3D accuracy is improved by 30–60% in block configuration and 15–25% in corridor configuration. A further improvement can be expected if a precise dating of image is available or if the camera positions can be directly extracted from GNSS data. Numéro de notice : A2020-018 Affiliation des auteurs : LASTIG MATIS+Ext (2012-2019) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2019.11.020 Date de publication en ligne : 16/12/2019 En ligne : https://doi.org/10.1016/j.isprsjprs.2019.11.020 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94456
in ISPRS Journal of photogrammetry and remote sensing > vol 160 (February 2020) . - pp 51 - 66[article]Exemplaires(3)
Code-barres Cote Support Localisation Section Disponibilité 081-2020021 RAB Revue Centre de documentation En réserve L003 Disponible 081-2020023 DEP-RECP Revue LASTIG Dépôt en unité Exclu du prêt 081-2020022 DEP-RECF Revue Nancy Dépôt en unité Exclu du prêt
Titre : Simulation and analysis of photogrammetric UAV image blocks - Influence of camera calibration error Type de document : Article/Communication Auteurs : Yilin Zhou Année de publication : 2020 Projets : 1-Pas de projet / Article en page(s) : n° 22 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] bloc d'images
[Termes IGN] compensation par faisceaux
[Termes IGN] effet thermique
[Termes IGN] étalonnage de chambre métrique
[Termes IGN] image captée par drone
[Termes IGN] obturateur
[Termes IGN] prise de vue aérienneRésumé : (auteur) Unmanned aerial vehicles (UAV) are increasingly used for topographic mapping. The camera calibration for UAV image blocks can be performed a priori or during the bundle block adjustment (self-calibration). For an area of interest with flat scene and corridor configuration, the focal length of camera is highly correlated with the height of the camera. Furthermore, systematic errors of camera calibration accumulate on the longer dimension and cause deformation. Therefore, special precautions must be taken when estimating camera calibration parameters. In order to better investigate the impact of camera calibration errors, a synthetic, error-free aerial image block is generated to simulate several issues of interest. Firstly, the erroneous focal length in the case of camera pre-calibration is studied. Nadir images are not able to prevent camera poses from drifting to compensate for the erroneous focal length, whereas the inclusion of oblique images brings significant improvement. Secondly, the case where the focal length varies gradually (e.g., when the camera subject to temperature changes) is investigated. The neglect of this phenomenon can substantially degrade the 3D measurement accuracy. Different flight configurations and flight orders are analyzed, the combination of oblique and nadir images shows better performance. At last, the rolling shutter effect is investigated. The influence of camera rotational motion on the final accuracy is negligible compared to that of the translational motion. The acquisition configurations investigated are not able to mitigate the degradation introduced by the rolling shutter effect. Other solutions such as correcting image measurements or including camera motion parameters in the bundle block adjustment should be exploited. Numéro de notice : A2020-415 Affiliation des auteurs : LASTIG MATIS (2012-2019) Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/rs12010022 Date de publication en ligne : 19/12/2019 En ligne : https://doi.org/10.3390/rs12010022 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95503
in Remote sensing > vol 12 n° 1 (January 2020) . - n° 22[article]100% automatic metrology with UAV photogrammetry and embedded GPS, and its application in dike monitoring / Yilin Zhou (2019)
Titre : 100% automatic metrology with UAV photogrammetry and embedded GPS, and its application in dike monitoring Titre original : Métrologie 100 % automatique par photogrammétrie aéroportée légère et GPS de précision permanent et embarqué : application au suivi de digues Type de document : Thèse/HDR Auteurs : Yilin Zhou Editeur : Champs/Marne : Université Paris-Est Marne-la-Vallée UPEM Année de publication : 2019 Importance : 181 p. Format : 21 x 30 cm Note générale : bibliographie
Thèse de Doctorat de l'Université Paris-Est, Sciences et Technologies de l'Information GéographiqueLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] angle nadiral
[Termes IGN] digue
[Termes IGN] données GNSS
[Termes IGN] effet thermique
[Termes IGN] étalonnage de chambre métrique
[Termes IGN] image aérienne
[Termes IGN] image aérienne oblique
[Termes IGN] image captée par drone
[Termes IGN] modélisation 3D
[Termes IGN] obturateur
[Termes IGN] photogrammétrie métrologique
[Termes IGN] point d'appui
[Termes IGN] réseau fluvialIndex. décimale : THESE Thèses et HDR Résumé : (auteur) The development of unmanned aerial vehicle (UAV) platform makes it nowadays a valuable source of data for inspection, surveillance, mapping and 3D modeling issues. UAV photogrammetry opens various new applications in close-range aerial domain and introduces a low-cost alternative to classical manned vehicle photogrammetry. Corridor mapping, one of the fields with substantial importance for UAV photo-grarnmetry, is largely demanded in the surveillance and management of infrastructure assets — highways, railways, waterways and pipelines. Due to the special geometry of the scene, corridor mapping is one case that needs taking precautions. Errors accumu-late easily on the longer dimension of the scene and a bowl effect is often observed; the flatness of the scene introduces strong correlations between parameters to be determi-ned, these two factors together, make it more difficult to obtain high accuracy results in corridor configuration than in classical ones. This thesis is a research project initiated by the CNR, a river concessionary, which has the responsibility of the maintenance and surveillance of its hydraulic facilities, more particularly the dikes. The objective is to apply UAV photogrammetry, which is faster, cheaper and offers a 3D dense reconstruction of the scene, to the monitoring of dikes. While maintaining a high surveying accuracy, a reduced field work, i.e. the number of ground control points (GCPs) is expected. In the first place, simulations are carried out to gain an insight of several problems of corridor mapping that impact the final accuracy. Then, thorough investigations are conducted on three aspects that interest us the most. The first study focuses on the aerial acquisition geometry, discussions are given on the influence of oblique images, nadir images of different flight heights as well as the possibility of an in-flight camera calibration and its application on unfavourable acquisition geometry. The second study aims to improve the acquisition performance for high-end metric cameras. The image deformation introduced by camera temperature variation is investigated and modelled. A method for the correction of this thermal effect is proposed, its performance is eva-luated on both terrestrial and aerial datasets of corridor configuration. The last study interests in the rolling shutter effect for consumer-grade cameras, which is commonly seen in UAV platforms on the market. Two methods are presented to calibrate the camera readout time, a property that is often not given by camera manufacturers. A two-step method is proposed for the correction of rolling shutter effect, its performance is evaluated in both block and corridor configurations. Note de contenu : 1- Introduction en français
2- Introduction
3- State of the art
4- Simulation and analysis
5- Study of aerial acquisition geometry
6- Study of thermal effect
7- Study of rolling shutter effect
8- Conclusion and perspectiveNuméro de notice : 25522 Affiliation des auteurs : LASTIG LOEMI (2012-2019) Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Géophysique : Paris-Est : 2019 Organisme de stage : LaSTIG (IGN) nature-HAL : Thèse DOI : sans Date de publication en ligne : 11/02/2020 En ligne : https://hal.science/tel-02474315v2/ Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94383 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 25522-01 THESE Livre Centre de documentation Thèses Disponible PermalinkLes mesures sur photographies aériennes : étude critique des facteurs limitant leur précision, 1. [Texte] / J. Hazan (ca : 1962)
PermalinkPermalinkPermalinkPermalinkCoup d'œil d'ensemble sur la photogrammétrie aérienne et terrestre, 2. Les appareils de redressement et de restitution des photographies, applications de la photogrammétrie à l'établissement des plans et des cartes / Raymond Martin (1940)
PermalinkPermalinkPermalinkPermalinkCongrès International de la Photographie, 23 - 28 juillet 1900, Exposition Universelle, Paris, France, 1. Procès-verbaux, rapports, notes et documents divers / Sosthène Pector (1901)
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