Network of robot boats with hydrophones deployed to monitor subsea activity

A network of autonomous vessels, each with a hydrophone on board, has been deployed to create a distributed surveillance network during a short-term maritime robotics exercise.

Passive sonar monitoring in this trial involves six 1.2-m robotic sailboats deployed in a line to be tested against live targets.

Plymouth, UK-headquartered Oshen is demonstrating what it is calling a world-first “acoustic picket line” capability with these C-Star uncrewed boats and hydrophones.

It uses a line of small vessels with low-cost sensors, supplied by Systems Engineering and Assessment, spread over a wide area to increase the likelihood of detecting underwater structures, objects, and movements in what can be a defence or commercial application.

C-Star autonomous boats can hold position to create an acoustic barrier across any stretch of water.

This network shape and density can be adjusted in response to operator requirements, while multi-perspective monitoring can identify the location, not just bearing, of a target.

Oshan sees this network as an alternative to passive sonar monitoring, which involves surface vessels pulling platforms fitted with up to 100 hydrophones behind them.

These provide excellent local sensing and bearing-finding capabilities, but are sensitive to noise pollution from the towing vessel or nearby ships and cover a limited area.