3D modeling of the “Pic du Midi d’Ossau” on the occasion of 70 years of UNGE (National Union of Surveyors Experts)
3 civil drone companies have formed a partnership under the UNGE (Union Nationale des Géomètres-Experts) banner to 3D model the Pic du midi d’Ossau, a 2884 meter high peak on the French side of the Pyrenees.
To celebrate the 70th UNGE anniversary, 3 leading companies of the civil drone industry, have closely cooperated as part of the land surveyor industry to map the Pic du Midi d’Ossau, with an accuracy ranging from 5 to 10 cm per pixel.
3D visualization of Pic du midi d’Ossau
Co-manager of the firm AirCity Diagnostic and civil drone operator in Aquitaine, in the south west of France, Loïc Richard was the project manager in charge of coordinating the operations and setting up the technological partnerships required for the success of the project.
« In order to map and model the Pic d’Ossau over such a wide area (about 400 ha), we naturally opted for the Parisian firm Aeromapper which engineers and exploits long endurance, long range drones (out of sight flying mode in accordance with the French S4 scenario legislation) This type of material can carry a 24 million pixel DSLR camera equipped with a high quality 19 mm focal lens which guarantees a unique accuracy and quality of image on the market. »
After the feasibility study and the acceptation of the project by Aeromapper, we could work alongside with Drones Imaging, a firm specialized in photogrammetry and in charge of post processing the data during this project.
« Through this collaborative work, we could master the value chain of a complex mission during which everyone provided their own assessments, ie flight-plan designing according to photogrammetric standards, high altitude flying or post-processing » Loïc Richard explained.
« One month before the mission started, a fiddly study of the Pic du midi d’Ossau allowed us to spot the various problematic areas of the peak. For instance, vertical shootings were completed with oblique ones to map rocky overhangs and thus cover the entire Ossau peak. Also the flight sampling strategy according to the sun brightness allowed us to reduce the shadow factor to have the best quality pictures » Loïc Hussenet, Drones Imaging CEO said.
October 2015, 17, after a 2 hour walk supporting a full back-pack drone equipment, the teams started taking the first aerial pictures at the foot of the peak. Ground targets had been dispatched in advance by land surveyors all around the peak.
From then on, after climbing 900 meters, Aeromapper’s AVEM started its automatic flight plan and recorded more than 1,500 pictures, at a 3,000 meters altitude. This extreme conditions flight was easily carried out thanks to this high-tech cartographic device and led to the complete Ossau peak 3D modeling.
A second operation is planned in 2016 to enhance measurements and flight plans but the first results are already promising thanks to the association of the land surveying and drone operating industries.