Microphone in noise-cancelling headsets worn by soldiers will send the location of an enemy sniper to the smartphones of troops in real-time – and it could be ready in just two years
- A soldier’s phone could be used to reveal the location of enemy troops
- It links the handset to a microphone built into their helmet’s ear protection
- Noise of fired bullets is tracked and used to reveal the assailant’s position
- Researchers say the technology could be on the battlefield within two years
Locations of enemy snipers shooting at troops may soon be revealed instantly on the smartphones of the ambushed troops.
Cutting-edge audio technology is being developed to use microphones in the ears of the soldiers to track two notable noises from a bullet – supersonic air in front of the bullet and the blast as it leaves the muzzle.
Technology is being developed to use these two sounds to trace the original location and reveal where it was fired from.
The data and location will then be relayed to the handset of the beleaguered troops to help them identify and neutralise the threat.
Audio experts that developed the technology say it builds on existing technology and could be employed on the battlefield in just two years.
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The system consisting of microphones and earmuffs or ear plugs is known as Tactical Communication and Protective Systems, or TCAPS. New technology uses the sounds caused as bullets zip past to pinpoint attackers and could be used on the battlefield within two years
The modern soldier’s helmet has inbuilt ear protection to protect them from the raucous of battle and a communication systems to talk to their comrades, other forces and HQ.
The system consists of microphones and either earmuffs or ear plugs and is known as Tactical Communication and Protective Systems, or TCAPS.
However, they currently are not used to find enemy assailants.
Combat acoustics researcher Dr Sébastien Hengy at the French-German Research Institute of Saint-Louis explained: ‘At the beginning of an ambush, the most important thing for soldiers is to know where the shooting is coming from so that they can hide on the right side of a vehicle or at least aim in the right direction – and they need this information very fast.’
So he developed a proof of concept that uses the microphones in a TCAPS system to capture a shooter’s acoustic information and transmit this to a soldier’s smartphone to display shooter location in real time.
TCAPS have four microphones, two outside the ear canal and two inside it, underneath the hearing protection.
The French prototype has an electronic filter that activates to block out loud noises, such as when a soldier fires his or her own weapon.
Revealing the shooter location uses the fact that most modern combat weapons fire bullets at supersonic speeds, creating two acoustic waves.
The first is a supersonic shock wave – similar to that formed in front of a jet at supersonic speeds – that travels in front of the bullet and propagates outward in a cone shape.
The explosion of the bullet in the barrel also creates a muzzle wave which radiates out spherically in all directions.
Dr Hengy said: ‘Our system uses the microphone underneath the hearing protection in order to detect the shock and muzzle waves generated by supersonic shots and record the time difference of arrival of the Mach wave between the left and right ear.
‘By combining the information sent by all the TCAPS deployed on the field, this gives you the direction of arrival of the waves and thus the direction in which the shooter is.’
Where a sniper is hidden or enemy troops are firing from in an ambush could soon be relayed to soldiers in real time – on their smartphone. The modern soldier’s helmet has inbuilt ear protection to protect them from the dine of battle and a communication systems to talk to their comrades, other forces and HQ
The location is then sent via Bluetooth or USB to a soldier’s smartphone which uses a data fusion algorithm developed by Dr Hengy to calculate the shooter’s position.
He added: ‘If it’s a smartphone with a good processor, the computation time to get the complete trajectory is about half a second.’
Once the soldier returns fire the location system automatically turns off.
Soldiers in France’s Operation Sentinel domestic anti-terror force are already equipped with smartphones.
To date, Dr Hengy has successfully demonstrated the system with microphones mounted ear width apart – about 10 cm – in a field.
The technology is currently being refined including integrating head orientation information from tiny compasses mounted in the hearing protection.
Later this year tests with the system on an artificial head is due to begin and, if all goes well, the technology could be deployed as early as 2021.
The TCAPS technology is being developed in collaboration with French company Cotral.
The TCAPS-based shooter location research was presented at the 177th Meeting of the Acoustical Society of America in Louisville, Kentucky.
