Evaluation of Acoustic UAV Tracking Methods

Abstract

With the recent growth in demand for UAV (Unmanned Aerial Vehicle), understanding their acoustic impact on humans has become increasingly important. For an accurate measurement of the emitted sound of UAVs in flight, precise knowledge of their position and attitude is indispensable. However, the performance of short-range three-dimensional acoustic UAV tracking is still an open issue. This study compares the accuracy of acoustic tracking methods, including frequency- and time-domain algorithms, to established tracking methods, such as optical tracking, differential GPS and Real-Time Kinematics (RTK). Experiments were conducted using a custom MEMS microphone array, allowing the measurement of sound hemispheres of flying UAVs in different flight phases, such as take-off, hover, cruise or general maneuvering. The design of the array was optimized considering the point spread function (PSF), microphone placement, spacing and size. Additionally, ground reflection effects and wind influences were considered. The acoustic measurement of the position was possible by employing specialized acoustic data processing and an estimation of the UAV’s acoustic signature. Results of this validation measurements will be presented.