Gunshot Airborne Surveillance with Rotary Wing UAV-Embedded Microphone Array

Area of Science:

• Acoustics
• Robotics
• Signal Processing

Background:

• Unmanned aerial vehicles (UAVs) are increasingly utilized in diverse applications.
• Gunshot surveillance systems can benefit from mobile platforms like drones.
• Acoustic sensing on UAVs faces challenges from propeller noise.

Purpose of the Study:

• To evaluate UAVs as platforms for gunshot surveillance systems.
• To investigate direction-of-arrival (DoA) estimation for shooter localization using muzzle blast sounds.
• To determine optimal preprocessing and DoA techniques for drone-based acoustic surveillance.

Main Methods:

• Utilizing microphone arrays mounted on UAVs for sound acquisition.
• Applying various direction-of-arrival (DoA) estimation algorithms to recorded audio.
• Employing both simulated and real-world gunshot data, including field recordings.
• Analyzing the impact of drone positioning on localization accuracy.

Main Results:

• Successful application of DoA estimation methods to drone-mounted microphone arrays.
• Identification of optimal preprocessing and DoA techniques for this specific application.
• Demonstration of high hit rates (approx. 96%) for gunshots recorded within a specific angular region relative to the drone.
• Validation of reliable bearing estimates achievable with UAV-based acoustic systems.

Conclusions:

• UAVs provide a viable platform for acoustic gunshot surveillance.
• Drone positioning is critical for accurate shooter localization.
• The proposed system demonstrates the potential for reliable bearing estimation using muzzle blast sounds.