Characterization of unmanned aircraft system acoustic noise

UAS (unmanned aircraft systems) are used in a variety of commercial and military enterprises. In military settings, being able to identify location as well as number of enemy UAS can lead to stronger strategic positioning or appropriate countermeasures. In community settings, UAS can be a source of annoyance. Recently, AFRL measured three different UAS flown by pilots from Sinclair Community College. These UAS included various sizes and blade amounts. They were flown back and forth through an array of 20 acoustic sensors at nominal thrust. In addition to flying through the array, they were also flown at heights of 15 feet and 100 ft above the array. Using both telemetry and acoustic data, spherical source characterizations of the systems can be derived. These three-dimensional characterizations can lead to a better understanding of UAS acoustics as well as improved measurement design. This study describes the recent measurement in detail, some preliminary analysis, and the lessons learned. Future analysis and testing will promote acoustic identification of a larger variety of UAS.UAS (unmanned aircraft systems) are used in a variety of commercial and military enterprises. In military settings, being able to identify location as well as number of enemy UAS can lead to stronger strategic positioning or appropriate countermeasures. In community settings, UAS