Outdoor measurement approach for assessing multicopter UAV noise directivity during flybys

<p dir="ltr">This contribution presents an outdoor measurement approach to assess the noise emission</p><p dir="ltr">patterns of flying multicopters. The measurement setup comprises three orthogonal</p><p dir="ltr">microphone line arrays. Postprocessing of recorded sound pressure time signals involves</p><p dir="ltr">reconstructing the flight path and compiling normalized sound pressure levels measured</p><p dir="ltr">at different relative angles into a noise hemisphere. The method is applied to multiple flybys</p><p dir="ltr">involving three distinct multicopter models. Reproducibility of results and variance in</p><p dir="ltr">frequency-dependent emission characteristics across models are addressed. The feasibility</p><p dir="ltr">and remaining challenges of integrating the employed setup and data processing into guidelines</p><p dir="ltr">for standardized measurements are discussed.</p>