Notifying, warning and alerting the public using unmanned aerial vehicle systems – report on field trials

The article presents a proposal for field testing unmanned aerial vehicle systems for public notification and warning as part of civil protection and civil defence activities. The methodology was developed based on an original concept developed in the course of desk research, instructor practice, scientific research results, and research and development work. The research was conducted on a DJI Matrice 4TD model with the AS1 speaker and consisted of assessing the intelligibility of an audio message transmitted from different distances (initial distances of 700 and 1000 metres) at a constant height of 40 metres. It was demonstrated that the effective transmission range was as much as 1000 m in a noise-free environment and 400 m in an environment with engine noise, compared to the manufacturer's declared range of 300 m.