Acoustic Intelligence ACINT


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Sep 21, 2020
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ACINT (Acoustic Intelligence) is the interception and recording of all complex acoustic waves that allows a smart processing for identification of a threat in complex environments.
Increasingly sophisticated sensor networks are now producing an avalanche of data of such magnitude that it is becoming difficult for operators to process it in real time.
Amount of data, multiplicity of data types and categories to manage create challenges that require the support of very big processing capabilities powered by Artificial Intelligence and Big data Analysis.

ACINT is applied mainly in two different fields of modern warfare:

  • Underwater environment, where the propagation of acoustic waves with a long range is possible to detect ships and submarines, with sonars.
    In case of submarines, they are increasingly navigating near coasts, in shallow waters, in acoustic environments that are both complex and disturbed.
    Their missions are also more varied.​
  • Ground environment: the application is oriented to ground sites or vehicle protection (and even helicopters) to detect and counter hostile gun shooting from enemy forces or snipers.
    The missions take place in “noisy environments”, where it is difficult to sort threats from environmental noises.​
In these two fields of application, an effective and reliable identification of the threats is based on a library of signatures built out of the record of acoustic signatures of targets and of complex environments.

In case of underwater applications, the acoustic signature of a surface ship or submarine is like its identity card that may report two levels:

  • The first is related to the class of ship (underwater or surface vessel) to which the detected vessel belongs (ships of the same class are equipped with the same types of propulsion which makes them recognizable)  Identification.​
  • The second is the typical signature of a particular ship; this signature differs from that of other ships in its class (a propeller moulded in a slightly different way or with a defect on one of the blades will make the signature of that ship different from that of any other ship of the same class)  Fingerprinting.​
Underwater applications:

  • Submarines require very high-performance acoustic systems in order to give the submarine the means to carry out its missions in the best conditions of safety and efficiency.
    These systems incorporate high-performance acoustic sensors.
    The combination of subsystems such as bow sonar, flank, obstacle avoidance, interception, and towed passive sonar allows the construction of solutions to ensure a panoramic view of the underwater environment to detect, locate and classify all short, medium and long-range targets and threats over a wide range of frequencies.​
  • Surface ships are equipped with Variable Immersion Sonars (or Variable Depth Sonars) can detect, locate and classify increasingly stealthy and efficient submarines under all environmental conditions.​
  • Mine Warfare ships acoustic systems consist of Hull Sonars, Variable Depth Sonar, and Synthetic Aperture Towed Sonar.​
Ground applications:

  • Sniper detection:
    Detection of enemy fire is an application of ACINT in the battlefield.
    Such acoustic equipment measures the shock wave at the exit of the gun barrel.
    The soldier can spot in a fraction of a second the origin of the shot, and thus retaliate by aiming.
    The drawback of this solution is that detection takes place after the fire has started.
    To anticipate the danger, a multi-spectral sensor with a data fusion engine can be used to locate the sniper before he fires.
    It is the coupling mong acoustic detection and infrared cameras, seismic sensors or laser detectors (to spot the bezel of a rifle), which allows to obtain a highly efficient alert and anticipation system, with a low rate of false alarm, and reaction times compatible with the implementation of counter-measure and adapted response.
    The principles of this acoustic equipment are based on the comparison between two acoustic waves emitted by the ball, to determine its direction and the quality of the wave. An algorithm, comparing the wave to a huge catalogue of sounds, allows knowing precisely the type of weapon. It is a kind of “enhanced ear”.
    The soldier can carry it with him anywhere in the field, and uses it to know where the enemy fire came from, and what weapon produced it.​
  • Vehicles Protection:
    Versions for the protection of heavy and light armoured vehicles, as well as armoured police vehicles are available in the form of acoustic networks mounted on the roofs of vehicles.
    Such a system may also include a screen showing the origin and identification of the shot.
    It is operating during combat attacks with multiple threats such as small arms fire, RPGs and mortars.​
  • Sensitive Sites Protection:
    Ground versions have also been designed to protect sensitive sites, whether permanent or temporary.
    A mission system following the monitoring approach offers a configurable and scalable suite consisting of 1 to 20 acoustic networks.
    The number of acoustic networks depends on the area to be covered.
    Data from the system and its sensors include GPS location of the threat, as well as azimuth, elevation and range.
    They can be deployed to improve surveillance and security of sensitive sites and events.
    These systems can be used in several types of operational configurations: military FOB, Border Control Post, Embassies, and Personality Gatherings.​
  • Helicopters Protection:
    Helicopter crews are often the target of fire during missions, sometimes without even being aware of the threat until it is too late.
    This same type of acoustic detection equipment (hostile fire acoustic indicator) is also used for the protection of helicopters. It warns pilots of the source of the shots, in less than a second, so that they can either take evasive action or engage.
    This system can be used as an autonomous hostile fire detection system or in conjunction with other threat warning systems to provide a comprehensive threat awareness capability.​

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