Noise Measurements of Tactical UAVs

This paper describes several noise measurement activities of GTRI to measure and understand the noise produced by tactical UAVs. As UAVs in the tactical class have begun to see much more use in the battlefield, it has become apparent that the noise produced by these aircraft affects their utility in certain roles. GTRI has thus undertaken to measure the noise of several UAVs through a series of static ground measurements, flyover measurements, and measurements taken in an anechoic chamber. The results indicate that propeller noise and engine exhaust noise are generally of equal importance for typical UAVs. The difficulties in measuring flyover noise are also discussed as are methods for extracting noise buried in back ground noise. Finally some discussions on UAV noise relative to UAV detection is provided along with some concepts which would serve to reduce UAV noise and thus reduce detectability.