With the forthcoming introduction of multi-rotor aerial systems into the airspace and the expectation that they will operate close to populated areas, noise emissions from this new type of noise sources are becoming a relevant research topic, mainly because their noise footprint has been reported to be more annoying than that of other conventional urban noise sources (at the same sound levels).

Specific techniques to adequately measure the sound radiated by small unmanned aerial systems (sUAS) are currently under development by international standards, aeronautical agencies, and researchers. This work is intended to be relevant in establishing common measurement protocols between environmental policy makers, stakeholders, drone companies and academia.

This paper presents the on-field multichannel methodology for sUAS noise characterization. In addition, preliminary results are presented by acoustic metrics (LAmax and SEL), directivity profiling over microphone positions, and the construction of noise hemispheres during a quadcopter overflight. Results can be presented in both the time and frequency domain, while back-propagation techniques were also included in the analysis from each microphone position.