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Multi-UAV surveillance over forested regions / Vengatesan Govindaraju in Photogrammetric Engineering & Remote Sensing, PERS, vol 80 n° 12 (December 2014)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 80 n° 12 (December 2014) . - pp 1129 - 1137 Titre : Multi-UAV surveillance over forested regions Type de document : Article/Communication Auteurs : Vengatesan Govindaraju, Auteur ; Gerard Leng, Auteur ; Zhang Qian, Auteur Année de publication : 2014 Article en page(s) : pp 1129 - 1137 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] couvert forestier [Termes IGN] diagramme de Voronoï [Termes IGN] drone [Termes IGN] point d'appui [Termes IGN] rayonnement incident [Termes IGN] relief [Termes IGN] simulation 3D [Termes IGN] tessellation Résumé : (auteur) S-UAVs (Small-Unmanned Aerial Vehicles) have emerged as low-cost alternatives for aerial surveillance over forests. However, they provide limited coverage owing to their low altitudes and short endurance. Therefore, a quick and effective surveillance necessitates optimal flying paths, maximizing ground visibility. Even though the occlusion of ground points due to vegetation is significant in forests, it is generally neglected. This paper proposes a probabilistic sensing model that incorporates both occlusions due to terrain and vegetation, in the visibility computations and presents a two-step approach to determine near-optimal flight paths: (a) waypoints are strategically deployed to enhance visibility, using centroidal Voronoi tessellation, and (b) flyable paths are designed using a clustered spiral-alternating algorithm. Simulation studies conducted on synthetic terrains and a reconstructed terrain, from satellite data of tree-cover and a Digital Elevation Model (DEM), show the effectiveness of the proposed method in improving the terrain visibility as compared to commonly used grid-based waypoints. Numéro de notice : A2014-669 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.14358/PERS.80.12.1129 En ligne : https://doi.org/10.14358/PERS.80.12.1129 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75128 [article]

Retrieval of spectral reflectance of high resolution multispectral imagery acquired with an autonomous unmanned aerial vehicle: AggieAir™ / Bushra Zaman in Photogrammetric Engineering & Remote Sensing, PERS, vol 80 n° 12 (December 2014)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 80 n° 12 (December 2014) . - pp 1139 - 1150 Titre : Retrieval of spectral reflectance of high resolution multispectral imagery acquired with an autonomous unmanned aerial vehicle: AggieAir™ Type de document : Article/Communication Auteurs : Bushra Zaman, Auteur ; Austin Jensen, Auteur ; Shannon R. Clemens, Auteur ; Mac McKee, Auteur Année de publication : 2014 Article en page(s) : pp 1139 - 1150 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] bande infrarouge [Termes IGN] drone [Termes IGN] éclairement énergétique [Termes IGN] étalonnage de capteur (imagerie) [Termes IGN] image à haute résolution [Termes IGN] image multibande [Termes IGN] orthophotoplan numérique [Termes IGN] prise de vue aérienne [Termes IGN] radiance [Termes IGN] réflectance spectrale [Termes IGN] Utah (Etas-Unis) Résumé : (auteur) This research presents a new semi-automatic model for converting raw AggieAir™ footprints in visible and near-infrared (Nin) bands into reflectance images. AggieAir, a new unmanned aerial vehicle (UAV) platform, is flown autonomously using pre-programmed flight plans at low altitudes to limit atmospheric effects. The UAV acquires high-resolution, multispectral images and has a flight duration of about 30 minutes. The sensors on board are twin cameras with duplicate settings and automatic mode disabled. A white Barium Sulfate (BaSO4j panel is used for reflectance calibration and in situ irradiance measurements. The spatial resolution of the imagery is 25 cm; the radiometric resolution is 8-bit. The raw images are mosaicked and orthorectified and the model converts their digital numbers (DN) to reflectance values. Imagery, acquired around local solar noon over wetlands on the Great Salt Lake. Utah, is used to illustrate the results. The model generates high quality images and the results are good. The reflectance values of vegetation in the NIR, Green and Red hands extracted at the test locations are consistent. The image processing, reflectance calculations, accuracy issues, with the proposed method are discussed. Numéro de notice : A2014 670 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.80.12.1139 En ligne : https://doi.org/10.14358/PERS.80.12.1139 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75129 [article]

High resolution imagery collection for post-disaster studies utilizing unmanned aircraft systems (UAS) / Stuart M. Adams in Photogrammetric Engineering & Remote Sensing, PERS, vol 80 n° 12 (December 2014)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 80 n° 12 (December 2014) . - pp 1161 - 1168 Titre : High resolution imagery collection for post-disaster studies utilizing unmanned aircraft systems (UAS) Type de document : Article/Communication Auteurs : Stuart M. Adams, Auteur ; Marc L. Levitan, Auteur ; Carol J. Friedland, Auteur Année de publication : 2014 Article en page(s) : pp 1161 - 1168 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] Alabama (Etats-Unis) [Termes IGN] catastrophe naturelle [Termes IGN] drone [Termes IGN] image à haute résolution [Termes IGN] photographie aérienne [Termes IGN] prise de vue aérienne [Termes IGN] tempête Résumé : (auteur) This paper examines the use of unmanned aircraft systems (UAS) to capture imagery for use in post-disaster field studies at the neighborhood and individual building level. A discussion of post-disaster imagery collection including satellite, aerial, and ground-based platforms is first presented. Applications of UAS in recent disasters as described in the literature are then surveyed, and a case study investigating UAS capabilities for imagery collection following an EF-3 tornado in northern Alabama on 02 March 2012 is presented. Case study considerations include the multi-rotor unmanned aerial vehicle (UAVj equipment and ground station, onboard imagery devices, flight considerations and capabilities, and imagery aid metadata collection capabilities of the UAS. Sample post-tornado imagery of building damage is shown, demonstrating the order of magnitude improvement in imagery resolution compared to traditional post-disaster aerial photography. Numéro de notice : A2014-671 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.80.12.1161 En ligne : https://doi.org/10.14358/PERS.80.12.1161 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=75130 [article]