Four Maroni villages in three days: waste sites at 1 cm per pixel
On the upper Maroni, the villages are linked to the coast only by the river or by plane, and waste is handled locally, in treatment units; according to the authority, unauthorised dumps usually lie close to these units. In October 2025 the Communauté de communes de l’Ouest guyanais, whose Saint-Laurent-du-Maroni storage facility we were already monitoring, asked us for aerial coverage of its sites in Grand-Santi, Maripasoula, Papaïchton and Loka. It also wanted to know whether the drone could estimate the volume of stored waste: the order therefore combined orthophotos, plans and volume calculations.
Five survey areas in three days
The flight authorisation requests for Grand-Santi and Maripasoula were sent in mid-January to the Collectivité territoriale de Guyane, with flight height limited to 50 m and a request for the air traffic schedule at the aerodromes concerned. From 2 to 4 February 2026, five areas were surveyed: two in Grand-Santi, one in Maripasoula, one in Papaïchton and one in Loka. Each area is flown at a height that gives 1 cm per pixel on the ground. The drone positions are recomputed back at base by post-processing, using data from the permanent GNSS network, without any real-time link to a reference station.
Delivered on 10 February, with a caveat
The deliverables went out on 10 February: for each area, a plan showing the orthophoto and the calculation of stored waste volumes. In the same delivery we pointed out in writing a limit of the method: through vegetation, photogrammetric volume calculations are not reliable, and a LiDAR survey would be more appropriate for accurate measurements in such conditions. The authority, which thanked the team for the quality of the work, also asked for the orthophotos on their own, without the layers: the five 1 cm orthophotos were sent on 11 February.
The same client in Saint-Laurent
This trip adds to the monitoring we have carried out since October 2024 for the same authority on the Saint-Laurent-du-Maroni waste storage facility: photos from the same viewpoints, a 3 cm orthophoto and a plan at each visit, two time-lapse cameras during cell filling, from November 2025 to March 2026, and the mapping of the Apatou waste collection centre in November 2025.
