Thales touts mini-sonar for underwater drones ahead of UK Navy pitch

PARIS — French defense-electronics firm Thales has developed a miniaturized sonar that can equip underwater drones to detect submarines, with plans to demonstrate the system to the United Kingdom’s Royal Navy at an event on Wednesday.

The new system brings a “dramatic reduction” in size and weight from traditional sonar systems, Ian McFarlane, sales director for underwater systems at Thales UK, told Defense News in a written reply to questions. Possible use cases include equipping underwater drones to act as an uncrewed “loyal wingman” for a nuclear attack submarine, McFarlane said.

As drones become ubiquitous in Western armed forces drawing lessons from the war in Ukraine, defense firms are developing smaller versions of their equipment to mount on unmanned systems. Leonardo, Thales, Hensoldt and Saab all presented small-form kit from electronic warfare to compact sensors in the past year, though much of the focus has been on unmanned aerial vehicles.

The new sonar “responds directly to the industry’s growing demand for lightweight, high-performance sensors suitable for autonomous and remotely operated systems,” McFarlane said. “For application on uncrewed underwater vehicles, we needed to adopt a fundamentally different approach that would allow sonars to be applied to a range of shapes and sizes of platform.”

Thales typically produces sonars as large, meters-long single panels designed for specific submarines or vessel types. For the Sonar76Nano prototype, the company developed sonar receiver panels about 75 centimeters square wide and 10cm thick that can be combined to create an array, and a smaller transmitter panel of about 40cm by 40cm.

The new system builds on work Thales did for the Sonar 2076 flank arrays deployed on Royal Navy submarines, and development from concept to real-world prototype took just 10 months, according to the company. It said the smaller sonar can be deployed an a wider range of UUVs than just “large high-value platforms.”

Miniaturization has been made possible by “significant” advances in electronic components, compact power sources and progress in transducer design, according to McFarlane. In sonar, the transducer converts electrical pulses into sound waves and receives the echos. The system will use artificial intelligence to enhance acoustic detection and accelerate target identification.

“By rethinking both the hardware and the overall system architecture, we’ve delivered a sonar solution that is much smaller and lighter than traditional systems, without compromising on performance,” the sales director said.

The smaller size helps reduce acquisition and operating costs, and allows the sonar system to be integrated on a wide range of autonomous underwater vehicles, according to McFarlane. He said the sonar provides “submarine-level” capabilities at a fraction of the size and cost.

An array can include as many as 48 receiver tiles and a transmitter per side of an underwater drone, with the tiles slotting together to make sure they don’t increase the acoustic signature of the UUV, according to McFarlane.

Drones equipped with the sonar could operate ahead of a submarine to extend the sensor net, or astern to check for potential followers, McFarlane said. Other use cases include as a “passive acoustic tripwire” by drifting or loitering in a location to monitor for threats, transmitting signals for decoy purposes, or as a node for underwater communications, he said.

Thales hasn’t received orders or formal expressions of interest for Sonar 76Nano yet, keeping it under wraps until the official launch, according to the sales director. He said Thales sees a key role in the U.K.’s Atlantic Bastion project, a planned network of drones, ships and surveillance aircraft for anti-submarine defense and to protect underwater cables and pipelines in the northern Atlantic.

“We anticipate strong interest from the Royal Navy and allied partners as we begin engagement following this announcement,” McFarlane said.