Acoustic counter-drone system: India’s CSIO brings down drones via their motion sensors

Indian scientists in Chandigarh have developed an acoustic counter-drone system that brings unauthorised drones down from the sky without any ammunition or laser. It comes from the Central Scientific Instruments Organisation (CSIO), as the Economic Times reports.

When high-intensity sound waves are aimed at a drone’s internal motion sensors, it crashes within seconds. Funding for the development came from IHUB-NTIHAC, a technology and cyber security hub at IIT Kanpur.

How the acoustic counter-drone system works

Conventional jammers interrupt radio signals. The new technology instead targets the MEMS gyroscopes: micro-electromechanical sensors with which the drone measures rotation rates and stabilises its attitude. Special loudspeakers, so-called transducers, emit sound at precisely the resonant frequency of these sensors. The sensors begin to oscillate uncontrollably, and the flight computer receives false readings. Because the drone now compensates for movements that do not exist, it begins to tumble and crashes. The radio link is not attacked – which is why the system also works against fully autonomous drones without remote control.

The background is the growing threat from cheap small drones in India, for example for smuggling drugs, weapons and counterfeit money across the border. The military significance of drones was also underlined by their massive use during Operation “Sindoor” last year.

According to experts, acoustic systems only reach a few hundred metres. An air force officer sees their place above all in point defence against micro and nano drones – especially in densely built-up cities where radar reaches its limits. Strong background noise, wind and unfavourable temperatures limit their effectiveness. The system is therefore not meant to replace radar and jammers but to complement them. At the same time, the modular system protects authorised drones in the same airspace. CSIO is now seeking industry partners for series production and marketing.