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3D acoustic situational awareness
Counter battery

MSRA

Solutions

Threat / end user issue

In a peer to peer conflict, weapon location radars used for counter battery purposes will be extremely vulnerable.
With aerial/satellite based surveillance available for the opponent, radars will be seen.

With electronic warfare means being omnipresent, radars will be triangulated and jammed. There is an urgent need for 24/7 persistent surveillance with (preferably) passive sensors.

With mobility being the key for survival on the battlefield, rapid re-deployable, or even truly mobile sensor capabilities are required. Therefore, the traditional sheer sound pressure based sound ranging capability becomes obsolete, as the triangular footprint of the sensor nodes is too large to be installed on a manned, or unmanned platform.

With the trend towards longer ranges and “shoot and scoot” drills, the concept of capturing the muzzle blast noise becomes questionable, as the speed of sound is too slow to provide timely localizations.

Our solution

The Mobile Sound Ranging Array firmware can be used for both target acquisition and fire control. The firmware requires a (mesh) network of CASTLE sensor nodes that can be installed on any military vehicle. It makes the MSRA in essence an unattended capability at low operating costs.

As the CASTLE sensor node is able to handle the signals from the 3 D shockwaves as well, the time to provide a localization is no longer dependent upon the speed of sound, but on the “speed of the round”.

Key characteristics

  • All weather, day and night
  • Available as ground and vehicle-based system
    • Vehicle mounted, unattended, requiring no manpower
    • Ground based, each sensor post to be deployed within ten minutes
  • Requires no line of sight
  • Hears all around in a full hemisphere
  • Passive
  • Detection and localization ranges:
    • Artillery: up to 20 km
    • Rockets: up to 7 km
    • Mortars: up to 12 km


The battlefield is saturated with a large number of vehicles carrying the CASTLE payload. The concept crosses the stovepipes. On their own, the CASTLEs may host firmware for vehicle survivability.

Networked by MANET radios, clusters of CASTLEs build an array capability that is able to detect and localize the hostile indirect firing positions. The number of sensor posts and the size of the grid will depend upon the circumstances (topography, vegetation, weather and the enemy using jamming techniques)

How does it work?

Whereas traditional sound ranging processes the (transient) signals of the blast during the launch, the MSRA capability also makes use of the (continuous) signals of the 3 D shockwaves generated at the tip of shells flying at supersonic speed.

With a substantial local signal processing capability inside the CASTLE, the required bandwidth to share results with other CASTLEs is moderate. Hence, there is little burden on the radio network also supporting voice and video. In essence, each sensor post is both a master and a slave. It makes the MSRA resilient against the (temporary) loss of a sensor post no longer able to provide a “handshake”.

Therefore, the MSRA is not a high value single target, but a distributed capability with gracefully improving or degrading performance.

Product set up

  • 10 Sensor posts, including:
  • 1 Command post, including:
  • 4 AMMS - sensor nodes per CASTLE
    Acoustic Master – computing device
    Weather station
    Georeferencing device
    Manet radio
    Battery box

  • Ruggedized laptop
    Manet radio

3D acoustic situational awareness