Field test comparison of various acoustic drone detection methods

Abstract

Acoustics methods for Unmanned Aerial Systems (UAS) detection have several advantages. They are low cost and passive, do not radiate any RF signals, and can provide UAS classification. The disadvantages of acoustic methods include shorter detection distances and susceptibility to acoustic noise. We present the results of field tests of several acoustic UAS detection methods. The tested systems included the Drone Acoustic Detection System (DADS) that was developed by Stevens Institute of Technology, a 16 microphone cross two-tier acoustic array, directional acoustic microphones (parabolic and shotgun microphones), and the OptiNav ACAM 120 acoustic array. The field tests were conducted to investigate the performance of various acoustic systems for UAS detection and tracking ability of various DJI models. Directional microphones and systems with many microphones did not demonstrate a significant advantage over the lower cost DADS that consists of three nodes, with each node having four microphones. Cross-correlation of signals between various microphone pairs is used for finding the acoustic signal direction of arrival. This system provides acoustic target detection and tracking. Classification software discriminates between a UAS and other possible targets, such as airplanes, helicopters, and ground vehicles. [Work supported by Air Force Research Laboratory under Contract No. FA8750-17-C-0190.]