Researchers in Australia are looking to the hover fly to help develop systems that can target the acoustic signatures of drone threats from up to 2.5 miles away.

Such bio-inspired design is not new. In fact, the vision systems of insects have been mapped for years in order to improve camera-based detection. However, utilizing the scientific methodology to collect acoustic data is a rather huge innovation.

"Bio-vision processing has been shown to greatly increase the detection range of drones in both visual and infrared data," says Anthony Finn, University of South Australia Professor of Autonomous Systems. "However, we have now shown we can pick up clear and crisp acoustic signatures of drones—including very small and quiet ones—using an algorithm based on the hover fly's visual system."

Hover flies pretty much do what they are named for—they can hover over plants to collect nectar. But hover flies also possess exceptional visual and tracking skills. For example, darkly lit areas are very noisy from an optical standpoint, but the hover fly is remarkably effective at capturing and processing visual data. Scientists are mapping this very same processing technique to acoustic detection, which can result in vastly improved detection capabilities—especially in noisy environments.

"Unauthorised drones pose distinctive threats to airports, individuals, and military bases," says Finn. "It is becoming ever-more critical for us to be able to detect specific locations of drones at long distances by using techniques that can pick up even the weakest signals. Our trials using the hover-fly-based algorithms show we can now do this."

The researchers looked at narrowband and broadband signals in order to pick up drone acoustics at short to medium distances. The bio-inspired processing technique reportedly improved detection ranges by between 30 percent and 49 percent. The findings were reported in The Journal of the Acoustical Society of America.