Pilot Confirms Gaps in Drone Navigation Safety in Helsinki

A pilot study has confirmed significant concerns regarding Global Navigation Satellite System (GNSS) interference at low altitudes within the city of Helsinki, a critical finding for the future of urban drone operations. This is a recent finding based on a GNSS interference pilot done last autumn. It was launched in response, to reports from the Helsinki’s local drone community of sudden, total loss of GNSS positioning, suggesting man-made interference is affecting airspace relevant to Unmanned Aerial Systems. GNSS is a satellite based navigation and positioning system commonly used by drones.

While existing data from manned aircraft confirms high-altitude jamming in the Gulf of Finland region, data was so far lacking for the lower airspace essential for urban drone logistics and flights such as longer distance drone flights also tested in Helsinki. The pilot study was conducted by the city owned innovation company Forum Virium Helsinki as part of the EU funded CITYAM project. The three year project supported cities in increasing urban air mobility responsibly. Among a policy roadmap and a landing site planning tool, the project organised multiple rounds of surveys to learn how citizens feel about drones.

Urban structures could block the interference

Data collected between April and November 2025 allowed the pilot team to analyse positioning deviation and categorise interference severity. Forum Virium Helsinki highlighted the importance of these findings for ensuring a safe testing environment for autonomous mobility solutions. The issue directly impacts the city’s readiness to host advanced drone operations, like the healthcare logistics flights that were piloted in late 2025 as part of CITYAM.

The pilot team of Forum Virium Helsinki had some ideas on how the work could be improved which included using existing sensor networks, finding optimal locations for the interference detection sensors via urban digital twins, and improving the sensors. The initial hypothesis – that urban structures might block intentional interference signals from reaching lower altitudes further inland – is being investigated further.

The sensor pilot concluded with several recommendations for broader, real-time interference detection. You can find all recommendations, approaches and key benefits in chapter 4.1 of the document: “UAM Use Cases & Landing Site Infrastructure – Lessons Learned from the CITYAM Lead Cities” (Deliverable 2.2 of CITYAM).

The study underscores a critical need for publicly available data and analysis regarding GNSS signal quality at low altitudes to safeguard future drone traffic.