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3D acoustic situational awareness
Vehicle survivability




Both manned and unmanned military vehicles face numerous kinds of direct fire, varying from incoming Small Arms Fire up to high kinetic armor piercing rounds.
Especially when under armor, or unmanned, maintaining situational awareness is key.

The enemy is most likely trying to control the electromagnetic spectrum. As a consequence, search and track radars will betray the position of the vehicle. They will be jammed when the enemy wants to.

Thus, there is an eminent need for passive sensors on the vehicles. Though the armor will usually protect the vehicle crew against small arms fire, there are other more threatening weapons, such as Rocket Propelled Grenades (RPGs), Anti-Tank Guided Missiles (ATGMs) and Armor Piercing Fin Stabilized Discarding Sabot (APFSDS) type of high kinetic weapons.

Active Protection Systems (APSs) are finding their inroads on armored vehicles. Hard kill is available, soft kill being developed.
The sensors to activate the countermeasure usually involve (passive) optical sensors and an (active) search & track radar.

As mentioned, active sensors betray the position of the vehicle and can be jammed. Optical systems can be dazzled. Therefore, there is a quest for other kind of sensors. This is where the CASTLE blends in.


ACCOPS firmware inhibits all the knowledge gained by Microflown AVISA in the counter battery domain where both launch noise and 3D shockwave signals are analyzed. If the formation has a local digital network between the vehicles equipped with a CASTLE, the network is at least able to localize the launch position of the threat being fired. Hence a second attack might be prevented. A stand alone CASTLE can provide a warning against an incoming subsonic threat.


  • All weather, day and night
  • Low size, weight and power
  • Passive system
  • Requires no line of sight
  • Detecting and localizing RPG’s up to 2000 m
  • Easy BMS/C2 integration
  • Operational when the vehicle is driving
  • Capable of separating vehicle induced noise from external, hostile, sound sources
  • Robustness against acoustic shadows and acoustic reflections caused by the vehicle deck
  • Capable of cueing remote weapon stations and cameras
  • Easy integration on various vehicle platforms, e.g. UGV’s, IFV’s, light tactical vehicles and APC’s


The performance of ACCOPS primarily depends upon the availability of a local digital network between the CASTLEs on the vehicles in the formation.
Furthermore, the speed of the incoming threat is of relevance for acoustic sensors.

A stand alone CASTLE will be able to pick up the noise of the launch before the threats hits the vehicle. The response time left depends upon the difference between the speed of the threat and the speed of sound and the stand-off distance between the launch position and the vehicle.

In case of a supersonic threat, governed by physics, the stand alone CASTLE on the vehicle under attack will not get the signals before the threat hits.
A network of CASTLEs in the formation will be able to localize the launch position of both subsonic and supersonic threats being launched.

Hence, a second attack might be prevented by the formation.
It is foreseen that the network of CASTLEs is also able to determine the trajectory of the threat, providing a warning to the vehicle under threat.


  • On the outside
  • On the inside
    • 4 AMMS - sensor nodes per CASTLE
    • Weather station
    • Georeferencing device (GNSS)
    • MANET radio (optional)
    • Acoustic Master – computing device
    • Ruggedized laptop (if required)

Additional information

Microflown AVISA drafts numerous white papers and other documents that are only available upon request though. Please contact us directly to request additional information based on your interest.

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3D acoustic situational awareness