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Ionospheric and receiver DCB-constrained multi-GNSS single-frequency PPP integrated with MEMS inertial measurements / Zhouzheng Gao in Journal of geodesy, vol 91 n° 11 (November 2017)
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Titre : Ionospheric and receiver DCB-constrained multi-GNSS single-frequency PPP integrated with MEMS inertial measurements Type de document : Article/Communication Auteurs : Zhouzheng Gao, Auteur ; Maorong Ge, Auteur ; Wenbin Shen, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 1351 – 1366 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] coordonnées GNSS
[Termes IGN] erreur instrumentale
[Termes IGN] erreur systématique
[Termes IGN] filtre de Kalman
[Termes IGN] GNSS en mode différentiel
[Termes IGN] GPS-INS
[Termes IGN] intégration de données
[Termes IGN] perturbation ionosphérique
[Termes IGN] positionnement ponctuel précis
[Termes IGN] récepteur monofréquence
[Termes IGN] retard ionosphèriqueRésumé : (Auteur) Single-frequency precise point positioning (SF-PPP) is a potential precise positioning technique due to the advantages of the high accuracy in positioning after convergence and the low cost in operation. However, there are still challenges limiting its applications at present, such as the long convergence time, the low reliability, and the poor satellite availability and continuity in kinematic applications. In recent years, the achievements in the dual-frequency PPP have confirmed that its performance can be significantly enhanced by employing the slant ionospheric delay and receiver differential code bias (DCB) constraint model, and the multi-constellation Global Navigation Satellite Systems (GNSS) data. Accordingly, we introduce the slant ionospheric delay and receiver DCB constraint model, and the multi-GNSS data in SF-PPP modular together. In order to further overcome the drawbacks of SF-PPP in terms of reliability, continuity, and accuracy in the signal easily blocking environments, the inertial measurements are also adopted in this paper. Finally, we form a new approach to tightly integrate the multi-GNSS single-frequency observations and inertial measurements together to ameliorate the performance of the ionospheric delay and receiver DCB-constrained SF-PPP. In such model, the inter-system bias between each two GNSS systems, the inter-frequency bias between each two GLONASS frequencies, the hardware errors of the inertial sensors, the slant ionospheric delays of each user-satellite pair, and the receiver DCB are estimated together with other parameters in a unique Kalman filter. To demonstrate its performance, the multi-GNSS and low-cost inertial data from a land-borne experiment are analyzed. The results indicate that visible positioning improvements in terms of accuracy, continuity, and reliability can be achieved in both open-sky and complex conditions while using the proposed model in this study compared to the conventional GPS SF-PPP. Numéro de notice : A2017-706 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-017-1029-7 En ligne : https://doi.org/10.1007/s00190-017-1029-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88087
in Journal of geodesy > vol 91 n° 11 (November 2017) . - pp 1351 – 1366[article]Mapping the height and spatial cover of features beneath the forest canopy at small-scales using airborne scanning discrete return Lidar / Matthew Sumnall in ISPRS Journal of photogrammetry and remote sensing, vol 133 (November 2017)
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Titre : Mapping the height and spatial cover of features beneath the forest canopy at small-scales using airborne scanning discrete return Lidar Type de document : Article/Communication Auteurs : Matthew Sumnall, Auteur ; Thomas R. Fox, Auteur ; Randolph H. Wynne, Auteur ; Valerie A. Thomas, Auteur Année de publication : 2017 Article en page(s) : pp 186 - 200 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] couvert forestier
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] estimation statistique
[Termes IGN] Etats-Unis
[Termes IGN] hauteur des arbres
[Termes IGN] inventaire forestier (techniques et méthodes)
[Termes IGN] lidar à retour d'onde complète
[Termes IGN] Pinophyta
[Termes IGN] Pinus taeda
[Termes IGN] sous-boisRésumé : (Auteur) The objective of the current study was to develop methods for estimating the height and horizontal coverage of the forest understorey using airborne Lidar data in three managed pine plantation forest typical of the south eastern USA. The current project demonstrates a two-step approach applied automatically across a given study site extent. The first operation divided the study site extent into a regularly spaced grid (25 × 25 m) and identified the potential height range of the main Loblolly pine canopy layer for each grid-cell through aggregating Lidar return height measurements into a ‘stack’ of vertical height bins describing the frequency of returns by height. Once height bins were created, the resulting vertical distributions were smoothed with a regression curve line function and the main canopy vertical layer was identified through the detection of local maxima and minima. The second operation sub-divided the 25 × 25 m grid-cell into 1 × 1 m horizontal grid, for which height-bin stacks were created for each cell. Vertical features below the main canopy were then identified at this scale in the same manner as in the previous step, and classified as understorey features if they were lower in height than the 25 × 25 m estimate of the main canopy layer. The heights of the tallest understorey and sub-canopy layers were kept, and used to produce a rasterized map of the understorey layer height at the 1 × 1 m scale. Lidar derived estimates of the 25 × 25 m lowest vertical extent of the coniferous canopy correlated highly with field data (R2 0.87; RMSE 2.1 m). Estimates of understorey horizontal cover ranged from R2 0.80 to 0.90 (RMSE 6.6–11.7%), and maximum understorey layer height ranged from R2 0.69 to 0.80 (RMSE 1.6–3.4 m) for the three study sites. The automated method deployed within the current study proved sufficient in determining the presence and absence of vegetation and artificial structures within the understorey portion of the current forest context, in addition to height and horizontal cover to a reasonable accuracy. Issues were encountered within older stands (e.g. more than 30 years old) where understorey deciduous vegetation layers intersected with the coniferous canopy layer, resulting in an underestimation of sub-dominant heights. Numéro de notice : A2017-726 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2017.10.002 En ligne : https://doi.org/10.1016/j.isprsjprs.2017.10.002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88411
in ISPRS Journal of photogrammetry and remote sensing > vol 133 (November 2017) . - pp 186 - 200[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2017111 RAB Revue Centre de documentation En réserve L003 Disponible 081-2017112 DEP-EAF Revue Nancy Dépôt en unité Exclu du prêt 081-2017113 DEP-EXM Revue Saint-Mandé Dépôt en unité Exclu du prêt 3D building model-assisted snapshot positioning algorithm / Rakesh Kumar in GPS solutions, vol 21 n° 4 (October 2017)
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Titre : 3D building model-assisted snapshot positioning algorithm Type de document : Article/Communication Auteurs : Rakesh Kumar, Auteur ; Mark G. Petovello, Auteur Année de publication : 2017 Article en page(s) : pp 1923 - 1935 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement
[Termes IGN] Calgary
[Termes IGN] compensation par moindres carrés
[Termes IGN] corrélateur
[Termes IGN] lancer de rayons
[Termes IGN] milieu urbain
[Termes IGN] modèle 3D de l'espace urbain
[Termes IGN] positionnement par GNSS
[Termes IGN] récepteur GNSS
[Termes IGN] résidu
[Termes IGN] trajet multipleRésumé : (Auteur) A method for constructively using non-line-of-sight GNSS signals from a snapshot of signal samples for positioning of users in urban areas is presented here. Using a 3D building model and a ray-tracing algorithm, the number of reception paths and the corresponding path delays of reflected signals are predicted, across a rid of candidate positions. These predictions are then used to compute a least squares fit to the GNSS receiver’s correlator outputs, and the position with smallest residuals is selected as the position estimate. Using data collected along 3.5 km of road in downtown Calgary, Canada, where buildings reach heights of over 200 m, the root-mean-square position error is below 10 m in the along-track and across-track directions. Compared to two pseudorange-based receivers, the proposed method yields RMS error improvements of at least 31% in the along-track direction, 63% in the across-track direction, and 53% in the horizontal plane. Numéro de notice : A2017-621 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-017-0661-2 En ligne : https://doi.org/10.1007/s10291-017-0661-2 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86931
in GPS solutions > vol 21 n° 4 (October 2017) . - pp 1923 - 1935[article]Efficient structure from motion for oblique UAV images based on maximal spanning tree expansion / San Jiang in ISPRS Journal of photogrammetry and remote sensing, vol 132 (October 2017)
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Titre : Efficient structure from motion for oblique UAV images based on maximal spanning tree expansion Type de document : Article/Communication Auteurs : San Jiang, Auteur ; Wanshou Jiang, Auteur Année de publication : 2017 Article en page(s) : pp 140 - 161 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] algorithme STA
[Termes IGN] compensation par faisceaux
[Termes IGN] drone
[Termes IGN] image aérienne oblique
[Termes IGN] reconstruction 3D
[Termes IGN] structure-from-motionRésumé : (Auteur) The primary contribution of this paper is an efficient Structure from Motion (SfM) solution for oblique unmanned aerial vehicle (UAV) images. First, an algorithm, considering spatial relationship constraints between image footprints, is designed for match pair selection with the assistance of UAV flight control data and oblique camera mounting angles. Second, a topological connection network (TCN), represented by an undirected weighted graph, is constructed from initial match pairs, which encodes the overlap areas and intersection angles into edge weights. Then, an algorithm, termed MST-Expansion, is proposed to extract the match graph from the TCN, where the TCN is first simplified by a maximum spanning tree (MST). By further analysis of the local structure in the MST, expansion operations are performed on the vertices of the MST for match graph enhancement, which is achieved by introducing critical connections in the expansion directions. Finally, guided by the match graph, an efficient SfM is proposed. Under extensive analysis and comparison, its performance is verified by using three oblique UAV datasets captured with different multi-camera systems. Experimental results demonstrate that the efficiency of image matching is improved, with speedup ratios ranging from 19 to 35, and competitive orientation accuracy is achieved from both relative bundle adjustment (BA) without GCPs (Ground Control Points) and absolute BA with GCPs. At the same time, images in the three datasets are successfully oriented. For the orientation of oblique UAV images, the proposed method can be a more efficient solution. Numéro de notice : A2017-642 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2017.09.004 En ligne : https://doi.org/10.1016/j.isprsjprs.2017.09.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86999
in ISPRS Journal of photogrammetry and remote sensing > vol 132 (October 2017) . - pp 140 - 161[article]Réservation
Réserver ce documentExemplaires(3)
Code-barres Cote Support Localisation Section Disponibilité 081-2017101 RAB Revue Centre de documentation En réserve L003 Disponible 081-2017102 DEP-EAF Revue Nancy Dépôt en unité Exclu du prêt 081-2017103 DEP-EXM Revue Saint-Mandé Dépôt en unité Exclu du prêt Evaluation of NTCM-BC and a proposed modification for single-frequency positioning / Xiaohong Zhang in GPS solutions, vol 21 n° 4 (October 2017)
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Titre : Evaluation of NTCM-BC and a proposed modification for single-frequency positioning Type de document : Article/Communication Auteurs : Xiaohong Zhang, Auteur ; Fujian Ma, Auteur ; Xiaodong Ren, Auteur ; et al., Auteur Année de publication : 2017 Article en page(s) : pp 1535 - 1548 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] atténuation du signal
[Termes IGN] modèle ionosphérique
[Termes IGN] Neustrelitz TEC model NTCM
[Termes IGN] positionnement par GNSS
[Termes IGN] récepteur monofréquence
[Termes IGN] teneur totale en électronsRésumé : (Auteur) Ionospheric delay is a dominant factor that affects the accuracy of single-frequency positioning. Thus, an empirical ionospheric model with high accuracy is very important for single-frequency users. This study proposes a modified empirical broadcast ionospheric model, called MNTCM-BC, based on the Neustrelitz Total Electron Content (TEC) broadcast model NTCM-BC. Nine daily ionospheric coefficients of these models are estimated using datasets of the previous day from 30 globally distributed Global Navigation Satellite System monitor stations, and the prediction performance of the MNTCM-BC is evaluated with the datasets of the current day from all 300 verification stations. The results show that the complex behavior of the ionosphere is well described by the MNTCM-BC, including the visibility of two ionization crests on both sides of the geomagnetic equator and the TEC variations that depend on the local time and geomagnetic latitude. In terms of the prediction accuracy, compared with the NTCM-BC, the main improvement in the MNTCM-BC is achieved in summer, whereas the accuracy is comparable in other seasons. Hence, the following analyses are focused on summer. In the low-solar activity year of 2009, the prediction accuracy of the MNTCM-BC is improved by 0.11 TECU compared with that of the NTCM-BC. As to the high-solar activity year of 2014, the corresponding improvement is 0.35 TECU. In addition, when the number of monitor stations is increased from 30 to 300, the prediction accuracy of two models can be slightly improved by 0.06 TECU in 2009 and 0.13 TECU in 2014, respectively, while reliability enhances. Furthermore, the average three-dimensional positioning accuracy of 160 globally distributed stations for single-frequency point positioning using the Klobuchar model, the NTCM-BC and the MNTCM-BC is 1.83, 1.21 and 1.20 m during quiet day and 3.15, 2.31 and 2.21 m during perturbed day, respectively. Relative to the Klobuchar model and the NTCM-BC, the average accuracy improvements in the MNTCM-BC are about 30 and 3%, respectively. Numéro de notice : A2017-615 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : 10.1007/s10291-017-0631-8 En ligne : https://doi.org/10.1007/s10291-017-0631-8 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=86925
in GPS solutions > vol 21 n° 4 (October 2017) . - pp 1535 - 1548[article]Experiences with the QDaedalus system for astrogeodetic determination of deflections of the vertical / Markus Hauk in Survey review, vol 49 n° 355 (October 2017)
PermalinkHeight uncertainty in digital terrain modelling with unmanned aircraft systems / Stig-Göran Mårtensson in Survey review, vol 49 n° 355 (October 2017)
PermalinkIonospheric correction using NTCM driven by GPS Klobuchar coefficients for GNSS applications / M.M. Hoque in GPS solutions, vol 21 n° 4 (October 2017)
PermalinkMobile precise trigonometric levelling system based on land vehicle: an alternative method for precise levelling / J. Zou in Survey review, vol 49 n° 355 (October 2017)
PermalinkPermalinkPeriodic signals in a pseudo-kinematic GPS coordinate time series depending on the antenna phase centre model – TRM55971.00 TZGD antenna case study / Karol Dawidowicz in Survey review, vol 49 n° 355 (October 2017)
PermalinkReal-time multi-GNSS single-frequency precise point positioning / Peter F. de Bakker in GPS solutions, vol 21 n° 4 (October 2017)
PermalinkAn empirical evaluation of three elevation change symbolization methods along routes in bicycle maps / Annina Brügger in Cartography and Geographic Information Science, Vol 44 n° 5 (September 2017)
PermalinkApplication of the undifferenced GNSS precise positioning in determining coordinates in national reference frames / Grzegorz Krzan in Artificial satellites, vol 52 n° 3 (September 2017)
PermalinkConsumer mass market accelerometers for GNSS anti-spoofing / Sherman Lo in Inside GNSS, vol 12 n° 5 (September - October 2017)
PermalinkDetermination of the ionospheric foF2 using a stand-alone GPS receiver / Dudy D Wijaya in Journal of geodesy, vol 91 n° 9 (September 2017)
PermalinkDocumentation of heritage buildings using close-range UAV images: dense matching issues, comparison and case studies / Arnadi Murtiyoso in Photogrammetric record, vol 32 n° 159 (September 2017)
Permalinkn° 2150 - septembre 2017 - Dossier : Drones et photogrammétrie, survol technique et réglementaire (Bulletin de Géomètre)
PermalinkDrones et photogrammétrie : Un outil dans l’ADN de la profession / Benoît Greuzat in Géomètre, n° 2150 (septembre 2017)
PermalinkEstudio de precision en la aerotriangulacion de bloques de imagenes obtenidas con UAV / Miguel Angel Lopez Gonzalez in Mapping : Teledetección, medio ambiante, cartografía, sistemas de información geográfica, vol 26 n° 185 (septembrie - octubre 2017)
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PermalinkGroup delay variations of GPS transmitting and receiving antennas / Lambert Wanninger in Journal of geodesy, vol 91 n° 9 (September 2017)
PermalinkMulti-dimensional and multi-temporal motion estimation of a beam surface during dynamic testing using low-frame rate digital cameras / I. Detchev in Applied geomatics, vol 9 n° 3 (September 2017)
PermalinkObject tracking with robotic total stations : current technologies and improvements based on image data / Matthias Ehrhart in Journal of applied geodesy, vol 11 n° 3 (September 2017)
PermalinkPerformance evaluation of single-frequency point positioning with GPS, GLONASS, BeiDou and Galileo / L. Pan in Survey review, vol 49 n° 354 (September 2017)
PermalinkPoint cloud refinement with self-calibration of a mobile multibeam lidar sensor / Houssem Nouira in Photogrammetric record, vol 32 n° 159 (September 2017)
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