Japan pursues greater undersea situational awareness

The Japan Maritime Self-Defense Force (JMSDF) will strengthen its ocean observation capabilities with new types of Unmanned Underwater Vehicles (UUVs) and long-range underwater acoustic communication systems, the service announced via its social media account on 7 February.

The JMSDF said it had signed contracts for “Type I and Type II” underwater gliders that will be used to perform oceanographic surveys, gathering information on water temperature, salinity, and currents. It did not disclose the specific types of UUVs that it had contracted for, but it posted images of the French Alseamar SeaExplorer and Teledyne Marine Slocum G3 buoyancy gliders.

Meanwhile, the service has also contracted with local electronics company NEC to develop the Long Distance Underwater Acoustic Communication Module for UUV control and positional awareness, as well as for underwater communication from ships. It added that performance tests of this system will be conducted from 2025.

NEC revealed in January that it had demonstrated stable two-way, long-distance communication using an experimental UUV – equipped with an early example of the acoustic communication module – to remotely control another UUV as it navigates at 2-3 knots at a distance of 2.5 kilometres, and to receive data collected by the UUV.

The company added that its communication module combines its sonar-related technology, including ultrasonic transducer technology and underwater equipment manufacturing technology, with NTT’s space-time equalisation technology.

The JMSDF presently uses the Mitsubishi Heavy Industries OZZ-5 UUV, which is based on a prototype developed by the Acquisition, Technology, and Logistics Agency (ATLA).  The OZZ-5 is equipped with a dual-imaging sonar suite that enables it to discern buried objects at low frequencies while providing the ability to perform high-resolution scans of exposed objects on the seabed.

The service also operates the Hydroid REMUS 600 Autonomous Underwater Vehicle (AUV) for use in Mine CounterMeasures (MCM) operations with the local designation of OZZ-2.

by Jr Ng