Can Drones Serve as Carriers for Acoustic Measurement Equipment?

We demonstrate the feasibility of accurate acoustic low-frequency measurements using microphones carried by a drone. A commercial octocopter drone was initially tested in laboratory settings and then modified to carry a microphone. We found that a drone’s self-noise is negligible in the low-frequency range below approximately 100 Hz, making it feasible to use drones as carriers for low-frequency sound measurement equipment. The optimal position for the equipment is in the rotor plane, where disturbances from self-noise and rotor flow are minimized. A test flight with a measurement drone around an artificial low-frequency source showed good measurement accuracy compared to ground-based measurements. We anticipate that drone-based sound measurements will be used for sound power and directivity measurements of large outdoor emitters, such as wind turbines or biogas power plants.