Outdoor measurement approach for assessing multicopter UAV noise directivity during flybys

This contribution presents an outdoor measurement approach to assess the noise emission

patterns of flying multicopters. The measurement setup comprises three orthogonal

microphone line arrays. Postprocessing of recorded sound pressure time signals involves

reconstructing the flight path and compiling normalized sound pressure levels measured

at different relative angles into a noise hemisphere. The method is applied to multiple flybys

involving three distinct multicopter models. Reproducibility of results and variance in

frequency-dependent emission characteristics across models are addressed. The feasibility

and remaining challenges of integrating the employed setup and data processing into guidelines

for standardized measurements are discussed.