Researchers and engineers from the University of Washington Applied Physics Laboratory have developed a preliminary design for an integrated system to detect and classify unexploded ordnance in shallow water. Their Multi-Sensor Towbody (MuST) is intended to survey depths from 20 – 120 feet deep (6 – 36 meters) by accurately controlling the height and location of sensors above the seabed while being towed by a support vessel. The system has a swath width of 18.8 meters when towed at 5 meters altitude.

Unlike highly-classified sensors used for mine countermeasures, the design uses sophisticated commercial off-the-shelf (COTS) components that can be operated by civilian contractors. The integrated MuST system consists of:

  1. A FOCUS-3 towbody made by MacArtney Underwater Technology to controllably maintain sensor height above the seabed while being towed by the vessel.
  2. An Edgetech 1600 kHz side-scan sonar giving seabed images of 1cm pixel size.
  3. A wide-band (5- 35 kHz) eBOSS sonar giving image voxels of ~10 cm (even if buried) for objects within the top 2 meters of seabed. Wide-band sonars can also create an “acoustic fingerprint” to classify buried munitions.
  4. Power, weight and data capacity for mounting other sensors on the towbody, such as magnetometers.
  5. Data acquisition, navigation, winch and handling systems that can be installed on a modest-sized tow vessel.

The MuST towbody supports two types of sonar as well as future sensors

SERDP-ESTCP researchers have investigated innovative acoustic, electromagnetic and magnetic sensors to detect, classify and locate underwater munitions at DoD sites in water depths of 0 – 120 feet deep. Each sensor modality has advantages and disadvantages due to its underlying physics. The MuST design shows how multiple sensors can be integrated into a commercially-viable system, while also being able to accept future sensors. Please contact the Munitions Response Program Manager if you have further questions about this research area.