Drones for forest studies
Drones are devices that enable data collection with high spatial and temporal resolution, solving some of the challenges faced in imaging tropical regions such as the extensive cloud cover and the temporal disparity between field collections and remote sensing satellite imagery. RGB (red-green-blue) images with a pixel size of up to 2 cm and surface elevation models of the entire surveyed area can be generated through photogrammetric processing of photographs captured by the onboard camera of a drone.
Mapping an area with a drone involves specifying the flight altitude and the total flight area (e.g. 100 meters above ground level and 50 ha). During the flight, photographs are captured with a high overlap (e.g. 80% overlap on the flight line and 70% overlap between flight lines). The parallax effect observed in the overlapping images reproduces the stereoscopic view (3D) and based on that, photogrammetry software generates an XYZ point cloud, a digital elevation model (DEM), and an RGB orthomosaic of the entire flight area. The size of the objects visualized in the orthomosaic reproduces their actual dimensions.
Data Collection
Video of the drone collection carried out in 2016 at the ZF-2 Station, located 50 km north of Manaus
Elevation Model
Surface elevation model (elevation in meters above sea level) with 26 cm spatial resolution produced through photogrammetric processing of images captured by a Phantom 4 drone in Amacayacu National Park, in the Colombian Amazon in 2019
Orthomosaic
RGB orthomosaic with a spatial resolution of 3 cm produced through photogrammetric processing of images captured by a Phantom 4 drone in the Amacayacu National Park, in the Colombian Amazon in 2019