Anechoic Chamber Measurement of an Octocopter

The proliferation of unmanned aerial vehicles or UAVs continues to create new or expanded commercial roles for these craft. Increased usage in residential areas to inspect roofs, deliver packages, or paint buildings has the potential to lead to several issues for communities where sound emission from these craft may become objectionable with the relatively low flight level, less than four hundred feet, of these UAVs. UAVs performing commercial tasks are typically larger with heavier lifting capacity than ones used the hobbyist. The Owens Corning Acoustic Research Center has provided sound power measurement of both fixed wing and multi-copter aircraft using the ISO 3745 standard in a fully anechoic chamber. The resulting sound power emission data can be used to project the sound of the UAV into the environment using available modeling techniques. This paper will describe testing results for a large UAV octocopter and compare results of varying microphone densities used for the measurement.