Experimental Evaluation of Acoustic Drone Tracking using Mobile Microphone Arrays

<p dir="ltr">With the latest increase in security threats from hostile civil or military UAVs, the need for suitable detection and defense systems is steadily growing. Even small commercial off-the-shelve drones pose a potential security risk when used as a means of attack and can hardly be countered with existing sensor technology. In the development of multi-sensor solutions, the acoustic domain has emerged as a valuable but still underestimated element. Typically, existing acoustic systems focus primarily on the stationary operation and detection or localization of a single drone. However, robust tracking is only achieved if detection and localization components are combined in order to associate a drone sound detection with the respective sound source(s). In this work, we present the development and experimental results of a mobile microphone array system that is able to detect and track multiple drones based on the direction of sound incidence. First, we describe the design and hardware implementation of a semi-spherical array of 32 microphones. Based on our previous work, we then elaborate ways to improve our track-before-detect approach for joint estimation of UAV sound presence and incidence. Finally, we evaluate our proposed system on a dataset acquired in the course of several measurement campaigns for a stationary as well as for a mobile scenario, where the microphone array was mounted on the roof of a vehicle.</p>