Bearing of unmanned aerial vehicles by a volumetric microphone array
Miriam Haege, Marc Oispuu · The Journal of the Acoustical Society of America · 2017
The technical abilities of Unmanned Aerial Vehicles (UAV, here also denoted as drones) are steadily increasing. UAVs are often equipped with state-of-the-art technology which enables illegal surveillance and mapping of terrains and buildings as well as smuggling or even terrorism. For this reason, sensor systems are required which detect the intrusion of incoming drones in safety-relevant areas at an early stage. Beside other means, acoustical sensors can be used to detect approaching drones. In this paper we will present a volumetric array consisiting of 12 microphones, which enables to monitor the upper half sphere above the array. Efficient bearing algorithms like coherent or incoherent beamforming are employed to determine the direction of arrival (azimuth and elevation) of UAVs. These algorithms have also been tested within the framework of practical experiments. For this purpose, different types of UAVs flying on various courses around the microphone array were used. The performance of the applied algorithms as well as the microphone array could be successfully confirmed.