From GPS World:
3DroneMapping completed a project under tight time and space constraints — surveying a tiny tropical island without disturbing guests.
The 15-hectare island nine kilometers from the Zanzibar coast is isolated from the rest of the world. Surrounded by coral reefs and sandbars, the island is home to an exclusive resort, but its limited space is threatened by erosion from changing currents.
Developers are concerned that proposed structures will be washed out to sea in a few years. Because no plans or maps of the island have ever been drawn or surveyed, they felt it was important to provide scale and dimension to architects for a master plan.
The survey needed to include existing structures, pathways, major trees, visible services, high-tide marks, levels and contours. It needed to be done in a tight timespan, before the island closed for renovations in three months. Also, the survey could not disturb any guests.
Using a custom-built multi-rotor drone with a high-resolution camera allowed 3DroneMapping to obtain images with good detail but taken far enough from guests to not bother them. Control points were located strategically, in places not visible to the public.
Luke Wijnberg, CEO of 3DroneMapping, conducted the survey with the L1 Reach by Emlid. “Such a survey could not have been possible without drones and Reach kit,” Wijnberg wrote in a blog. “Using this technology kept the pricing low for the customer, kept time on the ground and disturbance to guests to a minimum and provided a very quick turnabout time.”
After fieldwork was completed, the photogrammetric process was a fairly simple affair with 600 images collected and control added to the model. A high over and sidelap was required to obtain ground strikes between the vegetation.
The ground strikes were then extracted from the dense point cloud using specialized 3D point cloud editing and classification software. Other features were exported to a CAD program.
All files were handed to the client via an online GIS platform with AutoCAD files for the master planners.
Learn more about the project on the 3DroneMapping website.