Detection of continuous ground-based acoustic sources via unmanned aerial vehicles
Brendan Harvey, Siu O’Young · Journal of Unmanned Vehicle Systems · 2015
This paper presents the results of experiments that were conducted to partially establish the viability of utilizing acoustic sensing as a sense-and-avoid system for unmanned aerial vehicles (UAV). Experiments were conducted in which a UAV fitted with four acoustic sensors was flown under autopilot control at various altitudes over a loud speaker located on the ground acting as a continuous acoustic source. Various physical and digital noise reduction techniques were employed to enhance the recorded signals to allow increased detection ranges. Using standard free-field acoustic attenuation laws, maximum expected detection distances were calculated and presented. Depending on the acoustic source frequency signature and filtering method used, maximum expected detection distances ranged anywhere from 0.45 to 4.21 km on average with signal-to-noise ratios ranging from 10.3 to 37.0. Based on the results obtained, it is expected that acoustic techniques could facilitate the detection of an airborne source (aircraft) at distances great enough to facilitate an avoidance maneuver.