City-Scale Open Community Drone Mapping - A World First in Sierra Leone?

Room: Talks II

Sunday, 09:30
Duration: 20 minutes (plus Q&A)

This event will not be recorded.

• Tommy Charles

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.

This drone mapping campaign in Freetown was successfully implemented because of a great team, open source software and low cost drones, but other factors were also critical to its success and these will be shared to benefit others looking to establish similar initiatives. As such, our talk would cover: ● Background and context ● Pilot projects conducted in Freetown ● Institutional engagements and collaborations ● Securing funding ● Navigating regulatory environments to acquire community drone licenses and permits ● Training and recruiting pilots and imagery processors ● City wide drone mapping implementation ● File management and processing ● The things that surprised us and our lessons learnt ● What happens next - what we are building on top of the imagery as a consortium