In April and May, 2025, in Freetown, 13 of the city’s residents became the first open drone
mapping crew to take on the mapping of an entire capital city, creating a contiguous layer of
high quality (sub-5cm) open aerial imagery, as well as 3d meshes and elevation models.
The crew represented a mix of city stakeholders from Freetown City Council (FCC), Federation
of Urban and Rural Poor (FEDURP), Centre of Dialogue on Human Settlement and Poverty
Alleviation (CODOHSAPA) and OpenStreetMap Sierra Leone and the initiative was funded by
Humanitarian OpenStreetMap Team (HOT) and GIZ at the request of Freetown City Council to
support a host of urban development use cases including access to essential services analysis
for people with disabilities, living in informal settlements.
The open mapping world is incredible because it allows people, communities and organisations
to take autonomous action, creating and using geographical data to make positive change.
However, imagery remains a significant dependency.
Much mapping depends on access to good quality aerial imagery and this still largely means
using whatever is available through accessible imagery layers provided by corporations or
purchasing imagery at commercial rates. Exceptions to this, such as Maxar’s Open Data
Program, contribute freely licensed imagery but are limited to disaster response activations or
are at the discretion of Maxar’s decision makers.
The increasingly low price and high performance of low-cost drones has long promised to
disrupt this status quo and the development of OpenAerialMap and OpenDroneMap have
already contributed significantly to making this possible. The latest FOSS tooling to be added to
this ecosystem is Drone Tasking Manager, which does for drone mapping what the HOT Tasking
Manager does for remote mapping; enabling community members to participate in large scale,
coordinated campaigns with built in quality checks.
We propose to demonstrate to the State of the Map audience how local people with low-cost,
consumer-grade drones and an open tech stack can now deliver high quality aerial imagery for
city authorities and urban communities at a city scale and for a fraction of the cost of
comparable satellite imagery or commercially-flown drone imagery.