According to Ukrainian sources, Russian military forces have begun using FPV-type UAVs equipped with microphones for acoustic detection of the positions of UAV operators and Ground Robotic Systems (GRS).
It involves using sound as another source of intelligence. The microphones can record the noise of engines, running machinery and other sounds that may indicate the presence of people or equipment.
Ukrainian sources claim that these UAVs can be used to identify areas where UAV and GRS teams are operating. The information gathered can then be used to organize further surveillance of the identified area.
This type of practice has already been seen in the past with UAV patrols, where operators use voice to determine the presence of equipment beyond the line of sight of the cameras. The difference in this new method is the apparently deliberate use of the acoustic channel to locate ground-based objects.
Acoustic tracking can be particularly effective with FPV drones deployed on the ground in standby mode. When the motors are off, the noise of the drone itself is minimal, while the microphone allows the operator to hear what is happening nearby.
The technology is being used by both parties. Russian manufacturer Oshkonik previously reported using microphones on fiber-optic FPV UAVs called "Prince Vandal of Novgorodsky. "Ukrainian company Petchka Drones has equipped its UAVs with acoustic sensors.
According to the Ukrainian entrepreneur, the Russian system allegedly enables the detection of loud speech at a distance of 20-30 meters, light vehicles at a distance of 50-100 meters and heavy equipment up to 200 meters. These data depend on the ambient noise and the terrain.
-- Military Chronicle.