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Mapping with small UAS: A point cloud accuracy assessment / Charles K. Toth in Journal of applied geodesy, vol 9 n° 4 (December 2015)  

Public [article]  inJournal of applied geodesy > vol 9 n° 4 (December 2015) . - pp 213 - 226 Titre : Mapping with small UAS: A point cloud accuracy assessment Type de document : Article/Communication Auteurs : Charles K. Toth, Auteur ; Grzegorz Jóźków, Auteur ; Dorota A. Grejner-Brzezinska, Auteur Année de publication : 2015 Article en page(s) : pp 213 - 226 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] analyse comparative [Termes IGN] caractérisation [Termes IGN] drone [Termes IGN] géoréférencement direct [Termes IGN] image optique [Termes IGN] qualité des données [Termes IGN] semis de points Résumé : (auteur) Interest in using inexpensive Unmanned Aerial System (UAS) technology for topographic mapping has recently significantly increased. Small UAS platforms equipped with consumer grade cameras can easily acquire high-resolution aerial imagery allowing for dense point cloud generation, followed by surface model creation and orthophoto production. In contrast to conventional airborne mapping systems, UAS has limited ground coverage due to low flying height and limited flying time, yet it offers an attractive alternative to high performance airborne systems, as the cost of the sensors and platform, and the flight logistics, is relatively low. In addition, UAS is better suited for small area data acquisitions and to acquire data in difficult to access areas, such as urban canyons or densely built-up environments. The main question with respect to the use of UAS is whether the inexpensive consumer sensors installed in UAS platforms can provide the geospatial data quality comparable to that provided by conventional systems. This study aims at the performance evaluation of the current practice of UAS-based topographic mapping by reviewing the practical aspects of sensor configuration, georeferencing and point cloud generation, including comparisons between sensor types and processing tools. The main objective is to provide accuracy characterization and practical information for selecting and using UAS solutions in general mapping applications. The analysis is based on statistical evaluation as well as visual examination of experimental data acquired by a Bergen octocopter with three different image sensor configurations, including a GoPro HERO3+ Black Edition, a Nikon D800 DSLR and a Velodyne HDL-32. In addition, georeferencing data of varying quality were acquired and evaluated. The optical imagery was processed by using three commercial point cloud generation tools. Comparing point clouds created by active and passive sensors by using different quality sensors, and finally, by different commercial software tools, provides essential information for the performance validation of UAS technology. Numéro de notice : A2015--010 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1515/jag-2015-0017 En ligne : http://dx.doi.org/10.1515/jag-2015-0017 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80762 [article]

Positioning in challenging environments using ultra-wideband sensor networks / Zoltan Koppanyi in GPS world, vol 26 n° 3 (March 2015)  

Public [article]  inGPS world > vol 26 n° 3 (March 2015) Titre : Positioning in challenging environments using ultra-wideband sensor networks Type de document : Article/Communication Auteurs : Zoltan Koppanyi, Auteur ; Charles K. Toth, Auteur ; Dorota A. Grejner-Brzezinska, Auteur Année de publication : 2015 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement [Termes IGN] GNSS assisté pour la navigation [Termes IGN] onde radioélectrique [Termes IGN] positionnement en intérieur [Termes IGN] réseau de capteurs Résumé : (auteur) [...] Conventional radio transmissions use a variety of modulation techniques but most involve varying the amplitude, frequency and/or phase of a sinusoidal carrier wave. But in the late 1960s, it was shown that one could generate a signal as a sequence of very short pulses, which results in the signal energy being spread over a large part of the radio spectrum. Initially called pulse radio, the technique has become known as impulse radio ultra-wideband or just ultra-wideband (UWB) for short and by the 1990s a variety of practical transmission and reception technologies had been developed. The use of large transmission bandwidths offers a number of benefits, including accurate ranging and that application in particular is being actively developed for positioning and navigation in environments that are challenging to GNSS such as indoors and built-up areas. In this month’s column, we take a look at the work being carried out in this area by a team of researchers at The Ohio State University. Numéro de notice : A2015-265 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT/SOCIETE NUMERIQUE Nature : Article DOI : sans En ligne : http://gpsworld.com/innovation-where-are-we/ Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=76315 [article]

Challenged positions: Dynamic sensor network, distributed GPS aperture, and inter-nodal ranging signals / Dorota A. Grejner-Brzezinska in GPS world, vol 21 n° 9 (September 2010)

Public [article]  inGPS world > vol 21 n° 9 (September 2010) . - pp 35 - 42 Titre : Challenged positions: Dynamic sensor network, distributed GPS aperture, and inter-nodal ranging signals Type de document : Article/Communication Auteurs : Dorota A. Grejner-Brzezinska, Auteur ; Charles K. Toth, Auteur ; Inder Jeet Gupta, Auteur ; L. Li, Auteur ; X. Wang, Auteur Année de publication : 2010 Article en page(s) : pp 35 - 42 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement [Termes IGN] GPS assisté pour la navigation (technologies) [Termes IGN] onde radioélectrique [Termes IGN] positionnement par GPS [Termes IGN] radiofréquence [Termes IGN] réseau local sans fil Résumé : (Editeur) A performance assessment demonstrates the ability of a networked group of users to locate themselves and each other, navigate, and operate under adverse conditions in which an individual user would be impaired. The technique for robust GPS positioning in a dynamic sensor network uses a distributed GPS aperture and RF ranging signals among the network nodes. Numéro de notice : A2010-374 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30568 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
067-2010091	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Hybrid positioning: a prototype system for navigation in GPS-challenged environments / Chris Rizos in GPS world, vol 21 n° 3 (March 2010)

Public [article]  inGPS world > vol 21 n° 3 (March 2010) . - pp 42 - 47 Titre : Hybrid positioning: a prototype system for navigation in GPS-challenged environments Type de document : Article/Communication Auteurs : Chris Rizos, Auteur ; Dorota A. Grejner-Brzezinska, Auteur ; Charles K. Toth, Auteur ; A. Dempster, Auteur Année de publication : 2010 Article en page(s) : pp 42 - 47 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Navigation et positionnement [Termes IGN] atténuation du signal [Termes IGN] Australie [Termes IGN] géonavigateur [Termes IGN] GPS assisté pour la navigation (technologies) [Termes IGN] GPS-INS [Termes IGN] positionnement par GPS [Termes IGN] signal GPS [Termes IGN] système d'extension Résumé : (Editeur) GPS has its limitations. [...] We know GPS works very well when there is direct line-of-sight view between the satellite tranmitters and the receivers and carrier-phase measurements can provide decimeter- and even centimeter-accuacies. So why not develop a ground-based system that works in a similar way to GPS, which would allow you to place the transmitters wherever you like ? Well, such as a system has indeed been developed and this month's column, a team of australian and U.S. researchers describes how they integrated the ground-based system together with GPS and INS to create a hybrid system that provides precise and accurate position information continuously in a variety of environments where GPS alone comes up short. Copyright Questex Media Group Numéro de notice : A2010-082 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30278 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
067-2010031	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Extracting dynamic spatial data from airborne imaging sensors to support traffic flow estimation / Charles K. Toth in ISPRS Journal of photogrammetry and remote sensing, vol 61 n° 3-4 (December 2006)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 61 n° 3-4 (December 2006) . - pp 137 - 148 Titre : Extracting dynamic spatial data from airborne imaging sensors to support traffic flow estimation Type de document : Article/Communication Auteurs : Charles K. Toth, Auteur ; Dorota A. Grejner-Brzezinska, Auteur Année de publication : 2006 Article en page(s) : pp 137 - 148 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image [Termes IGN] caméra numérique [Termes IGN] extraction automatique [Termes IGN] image aérienne [Termes IGN] information géographique [Termes IGN] objet mobile [Termes IGN] réseau routier [Termes IGN] télémétrie laser aéroporté [Termes IGN] trafic routier Résumé : (Auteur) The recent transition from analog to totally digital data acquisition and processing techniques in airborne surveying represents a major milestone in the evolution of spatial information science and practice. On one hand, the improved quality of the primary sensor data can provide the foundation for better automation of the information extraction processes. This phenomenon is also strongly supported by continuously expanding computer technology, which offers almost unlimited processing power. On the other hand, the variety of the data, including rich information content and better temporal characteristics, acquired by the new digital sensors and coupled with rapidly advancing processing techniques, is broadening the applications of airborne surveying. One of these new application areas is traffic flow extraction aimed at supporting better traffic monitoring and management. Transportation mapping has always represented a significant segment of civilian mapping and is mainly concerned with road corridor mapping for design and engineering purposes, infrastructure mapping and facility management, and more recently, environmental mapping. In all these cases, the objective of the mapping is to extract the static features of the object space, such as man-made and natural objects, typically along the road network. In contrast, the traffic moving in the transportation network represents a very dynamic environment, which complicates the spatial data extraction processes as the signals of moving vehicles should be identified and removed. Rather than removing and discarding the signals, however, they can be turned into traffic flow information. This paper reviews initial research efforts to extract traffic flow information from laserscanner and digital camera sensors installed in airborne platforms. Copyright ISPRS Numéro de notice : A2006-602 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2006.09.010 En ligne : https://doi.org/10.1016/j.isprsjprs.2006.09.010 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28325 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
081-06091	RAB	Atlas / Beau livre	Centre de documentation	En réserve L003	Exclu du prêt

Analysis of long-range network RTK during a severe ionospheric storm / Pawel Wielgosz in Journal of geodesy, vol 79 n° 9 (December 2005)  

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On improving navigation accuracy of GPS/INS systems / Dorota A. Grejner-Brzezinska in Photogrammetric Engineering & Remote Sensing, PERS, vol 71 n° 4 (April 2005)  

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GQMAP: improving performance and productivity of mobile mapping systems through GPS quality of service / Hassan A. Karimi in Cartography and Geographic Information Science, vol 31 n° 3 (July 2004)  

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Redefining the paradigm of modern mobile mapping: an automated high-precision road centerline mapping system / Charles K. Toth in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 6 (June 2004)  

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From mobile mapping to telegeoinformatics: paradigm shift in geospatial data acquisition, processing, and management / Dorota A. Grejner-Brzezinska in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 2 (February 2004)  

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GPS + INS + pseudolites: an integrated positioning system / Y. Yi in GPS world, vol 14 n° 7 (July 2003)

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Sensor integration for improved surface modelling: DEM extraction from high-resolution digital imagery and laser altimetry / Charles K. Toth in GIM international, vol 13 n° 6 (June 1999)

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Analysis of GPS data processing techniques / Dorota A. Grejner-Brzezinska (1995)

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