Unmanned aerial vehicles (UAVs) are playing increasingly important roles in many fields. Ranging in size from the huge Global Hawk aircraft to hand-held machines, these remotely controlled devices are growing ever more vital to the U.S. armed forces in roles that include surveillance and reconnaissance.

In some instances, UAVs must fly close to their targets to gather data effectively and may evade enemy detection with sophisticated techniques like radar stealth, infrared stealth and special camouflage. Aeroacoustics researchers at the Georgia Tech Research Institute (GTRI) are investigating an additional kind of stealth that could also be vital to these UAVs