Photogrammetry for forest inventory; Lisein, Jonathan ![]() Conference (2013, March 12) Detailed reference viewed: 41 (4 ULg) Unmanned aerial survey of elephantsVermeulen, Cédric ; Lejeune, Philippe ; Lisein, Jonathan et alin PLoS ONE (2013), 8(2), The use of a UAS (Unmanned Aircraft System) was tested to survey large mammals in the Nazinga Game Ranch in the south of Burkina Faso. The Gatewing ×100™ equipped with a Ricoh GR III camera was used to ... [more ▼] The use of a UAS (Unmanned Aircraft System) was tested to survey large mammals in the Nazinga Game Ranch in the south of Burkina Faso. The Gatewing ×100™ equipped with a Ricoh GR III camera was used to test animal reaction as the UAS passed, and visibility on the images. No reaction was recorded as the UAS passed at a height of 100 m. Observations, made on a set of more than 7000 images, revealed that only elephants (Loxodonta africana) were easily visible while medium and small sized mammals were not. The easy observation of elephants allows experts to enumerate them on images acquired at a height of 100 m. We, therefore, implemented an aerial strip sample count along transects used for the annual wildlife foot count. A total of 34 elephants were recorded on 4 transects, each overflown twice. The elephant density was estimated at 2.47 elephants/km2 with a coefficient of variation (CV%) of 36.10%. The main drawback of our UAS was its low autonomy (45 min). Increased endurance of small UAS is required to replace manned aircraft survey of large areas (about 1000 km of transect per day vs 40 km for our UAS). The monitoring strategy should be adapted according to the sampling plan. Also, the UAS is as expensive as a second-hand light aircraft. However the logistic and flight implementation are easier, the running costs are lower and its use is safer. Technological evolution will make civil UAS more efficient, allowing them to compete with light aircraft for aerial wildlife surveys. [less ▲] Detailed reference viewed: 360 (21 ULg) Le drone : un nouvel outil au service de l'inventaire des ressources forestièresLisein, Jonathan ![]() Scientific conference (2013, January 15) Detailed reference viewed: 26 (6 ULg) Feasibility study for elephant inventory with an Unmanned Areal VehicleLisein, Jonathan ; Vermeulen, Cédric ; Bouché, Philippe et alScientific conference (2012, October 04) Detailed reference viewed: 36 (7 ULg) Creation of a Canopy Height Model from mini-UAV ImageryLisein, Jonathan ; Bonnet, Stéphanie ; Lejeune, Philippe ![]() Poster (2012, September 12) The arrival of mini-UAV (Unmanned Aerial Vehicle), these small autonomous aircrafts, has opened the doors to a new environmental data acquisition’s approach. In forestry, low-altitude imagery from UAV can ... [more ▼] The arrival of mini-UAV (Unmanned Aerial Vehicle), these small autonomous aircrafts, has opened the doors to a new environmental data acquisition’s approach. In forestry, low-altitude imagery from UAV can be used to characterize forest ecosystem structure through a Canopy Height Model (CHM). In this research, authors developed a new workflow for acquiring low-altitude aerial images with a mini-UAV and used them for the construction of a high resolution Canopy Height Model. An accuracy analysis is performed and shows that individual dominant tree height can be measured from (UAV-photo-) CHM with a precision of 2 meters. [less ▲] Detailed reference viewed: 119 (22 ULg) Developpement of an original aerial-based inventory method: first steps towards the use of mini Unmanned Areal Vehicle in elephant inventoryLisein, Jonathan ; Vermeulen, Cédric ; Bouché, Philippe et alScientific conference (2012, May 22) This research aims at developping a new methodology for counting large mammals by means of an unmanned aerial vehicle. Test flights have been performed in the game ranch of Nazinga (Burkina Faso) during ... [more ▼] This research aims at developping a new methodology for counting large mammals by means of an unmanned aerial vehicle. Test flights have been performed in the game ranch of Nazinga (Burkina Faso) during the month of february 2012. Aerial images shows that elephant detection is quite feasible. The systems still requires a lot of improvements in order to be able to cover bigger surfaces for a given pixels resolution. Nevertheless, this method seems very promissing and could advantageously replace traditionnal aerial-based inventory. [less ▲] Detailed reference viewed: 87 (19 ULg) Simuler la ressource forestière à l'échelle d'un massif : application de SIMMEM et GYMNOSLigot, Gauthier ; ; Perin, Jérôme et alConference (2012, April 02) Detailed reference viewed: 22 (8 ULg) |
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