China reveals next-gen submarine detection tech breakthrough

Notably, this frequency range not only carries substantial information but also offers environmental insights. Terahertz screening devices are already in use in some airports in China, where the technology helps to identify concealed items on passengers. Recent investments in 6G research have propelled advancements in terahertz applications, opening doors to mass utilization.

The team of researchers envisions a future where the terahertz submarine detection technology could be reduced into a package small enough to be mounted on a drone.

“A small unmanned aerial vehicle (UAV) platform has the advantage of good mobility, low cost and flexible deployment,” noted the researchers in the paper.

The integration of this technology with other submarine detection methods like magnetic anomaly detectors, microwave radar, or laser systems could provide comprehensive and crucial information for identifying submarines. 

Overcoming nature's barrier

The experiment was conducted at an unspecified location in the city of Dalian on the Yellow Sea. An artificial sound source simulated the noise emitted by a submarine, and an extended arm of a research ship was used to mimic a drone.

A submarine traveling at high speed “produces significant radiated noise that propagates to the water surface and excites surface vibration,” noted the team. This disturbance, barely noticeable when it reaches the surface, was previously thought impossible to distinguish from oceanic waves.

However, the terahertz sensor managed to distinguish man-made ripples – as tiny as 10 nanometers – from the natural waves of the ocean, an achievement the team attributes to both hardware and software innovations. 

The high frequency of terahertz waves contributes to their sensitivity, while the Chinese scientists pioneered an algorithm capable of effectively identifying these nanometer-sized ripples over the dynamic ocean surface.

Beyond detection, terahertz technology has also demonstrated promise in the realm of submarine communication. Submarines, known for their stealth, can leverage this technology to establish contact with friendly aircraft or other naval assets. 

“By detecting acoustically induced surface vibration signals, it is possible to invert the information conveyed by underwater sound sources,” the team said.

These encoded messages could be virtually undetectable by adversaries, enabling submarines to maintain secure and covert communication channels during large-scale military operations. 

The research team published their work in the Journal of Radars, a Chinese-language peer-reviewed journal, on August 11. The technology "will have significant application potential in underwater vessel detection and other areas," they remarked.