New submarine detector shows ‘tremendous potential’ in South China Sea tests

Beijingwalker

Elite Member
Joined
Nov 4, 2011
Messages
76,673
Reaction score
104,203
Country of Origin
Country of Residence

New submarine detector shows ‘tremendous potential’ in South China Sea tests

Shanghai team uses seabed to monitor low-frequency signals in new approach that captured electromagnetic waves 20km away


The detector, which is about the size of a pickup truck, was tested on a deep ocean seabed. Photo: Shanghai Jiao Tong University

Stephen Chenin Beijing

Published: 6:00am, 20 Sep 2024Updated: 7:12am, 20 Sep 2024

A new submarine detection technology that can track even the quietest of subs has shown potential during testing in the South China Sea, its developers say.
Scientists from Shanghai Jiao Tong University said their detector – about the size of a pickup truck – was tested on a deep ocean seabed.

It was able to capture faint electromagnetic waves generated by a rotating propeller nearly 20km (12 miles) away.

By analysing these low-frequency signals, the scientists said they could potentially position and track military targets. They published their findings in the Chinese peer-reviewed Journal of Vibration and Shock last month.

The detection range is about 10 times greater than anything previously reported, meaning the technology could potentially give China an advantage in an intensifying underwater arms race.
 
Here is the complete article

team of scientists from Shanghai Jiao Tong University in China has allegedly developed a new form of submarine detection that could transform underwater surveillance.

The device, which was claimed to have been tested in the depths of the South China Sea, has demonstrated the potential to detect even the quietest submarines over an extended range, a feat that was previously considered impossible.

breakthrough in electromagnetic detection
The new detection technology is in a large square-like pickup truck structure, and it uses antennas to detect very weak electromagnetic signals that submarine propellers emit.

The recent testing involved a rotating propeller, and the detector successfully identified low-frequency signals at a distance of nearly 12 miles (20 km), according to the South China Morning Post (SCMP).


Jiang Weikang, a professor at Shanghai Jiao Tong University’s State Key Laboratory of Mechanical System and Vibration, explained the significance of this development.

“Although a 1.86 miles (3 kms) detection and positioning range is already a significant breakthrough, it still falls short of meeting the requirements for detecting and positioning targets in the open sea,” Jiang wrote.

He emphasized that this new technology could potentially extend the detection range of these electromagnetic signals to over 31 miles (50 km), a distance comparable to that of modern torpedoes.

This achievement marks a significant improvement over previous records. Until now, the furthest detection of submarines using similar technology was just over 1.5 miles (2.5 km). a milestone also reached by Chinese scientists.

Sea bed detection: A new approach
Traditionally, detecting submarines using electromagnetic signals has been a challenge due to the nature of seawater, which tends to weaken electromagnetic waves. As propellers cut through the electric fields surrounding navy vessels, they generate electromagnetic radiation, but these signals are short-ranged in seawater.
However, the Shanghai scientists took a different approach—rather than receiving signals from the water, they collected them from the seabed.

As a submarine moves, its propellers rotate once per second, creating low-frequency electromagnetic waves that travel into the seabed and spread along rock layers. These waves weaken at a much slower rate in the seabed compared to seawater, allowing the detection range to be greatly extended.

According to the scientists, the rate of weakening in the seabed is only 0.278 decibels per mile (0.173 decibels per km), compared to the much higher rate in seawater.

“Marine geologists have used this method for years to explore undersea oil and gas deposits,” the scientists noted, adding that it had never before been applied to submarine detection.

The potential of this approach is immense, but it also presents several challenges, especially since the electromagnetic waves from the propellers are extremely weak by the time they reach the seabed.

Additionally, the seabed is filled with electromagnetic noise from both natural and non-military sources.

Overcoming challenges with advanced algorithms​

The research team created an advanced algorithm to isolate extremely weak signals in the noisy and complex seabed environment. Accurate positioning was another hurdle.

To pinpoint a target, the detector needs multiple high-precision sensors spread over a 0.62-mile (1 km) area, synchronized with an error margin of no more than a billionth of a second—challenging in deep-sea conditions.

“Low-frequency electromagnetic waves carry limited physical data, and researchers are still working to improve their use for more accurate target identification and positioning,” the paper highlighted (via SCMP).

Despite this, the researchers believe the technology holds immense promise, particularly in detecting submarines, which are increasingly difficult to spot using traditional acoustic methods.
The device itself is equipped with instruments and battery compartments for long-term underwater operations, and it is connected to a surface buoy. While primarily designed for submarine detection, the system can also track surface ships by identifying the wake of their propellers.

“We have achieved accurate detection of targets in the open sea,” the paper stated.

Implications for global submarine warfare​

The new technology comes at a critical time when underwater warfare is becoming a key area of focus for major military powers. Submarines have become increasingly stealthy, emitting sounds that are almost indistinguishable from background ocean noise. This poses a major challenge for traditional acoustic detection systems.


As tensions in the South China Sea and the Taiwan Strait continue to escalate, both China and the United States are investing heavily in anti-submarine warfare capabilities.
 
Last edited:
Even though off topic, can so me one tell if China, Taiwan, Japan or South Korea have networks similar to SOSUS?
 
Even though off topic, can so me one tell if China, Taiwan, Japan or South Korea have networks similar to SOSUS?
China certainly has Here it is the report from WSJ
The only good thing about the new WSJ journal report on the state of Chinese submarines is the underwater great wall is now functioning after so many years of construction not sure how they come to that conclusion. But assuming it is true China still needs a couple more years to hone on the new capability of combining Sossus with maritime patrol crat like Y 8Q and other PLAN assets Anyway here is a new article from AT

Aside from pump jet propulsion and increased submarine production capability, Asia Times has reported on China’s recent submarine technology advancements.

https://asiatimes.com/2023/11/us-yielding-its-submarine-warfare-edge-over-china/
Asia Times reported in September that Chinese researchers have developed a groundbreaking terahertz-based submarine detection technology, marking a significant advance in underwater warfare capabilities. The technology has the potential to challenge significantly US submarine operations.

The new detection device operates in the terahertz frequency range between microwave and infrared radiation and can identify minute surface vibrations, as small as 10 nanometers, created by low-frequency sound sources in the open sea.

These vibrations can locate submarines and gather intelligence for analyzing noise signatures to determine a submarine’s model. The technology, which could be incorporated into underwater drones, represents a considerable leap in identifying and potentially countering stealthy US submarine operations.

Furthermore, Asia Times reported in August that Chinese researchers have used computer modeling to identify the tiny bubbles produced by nuclear submarines, which previously went nearly undetected.

They discovered that the extremely low frequency (ELF) signals generated by these bubbles are much stronger than the sensitivities of current advanced magnetic anomaly detectors.

These bubbles form due to shifts in kinetic and potential energy as a submarine cruises, leading to turbulence and an electromagnetic signature through the magnetohydrodynamic (MHD) effect.

Non-acoustic detection techniques have been known for decades but are only now becoming practical due to advancements in computing power. Improving sensor resolution, processing power and machine autonomy will expand the range of detectable signals, enabling the distinction of previously indistinguishable signals.

Russia may also boost China’s submarine technology, with China possibly building its next-generation submarines with the help of Russian technical expertise.

In October, Asia Times reported on China’s possible collaboration with Russia in building its Type 096 nuclear ballistic missile submarine (SSBN), which is expected to be operational within the decade.
 
Here is WSJ report

At the same time, the western Pacific is becoming more treacherous for U.S. submarines. Beijing has built or nearly finished several underwater sensor networks, known as the “Underwater Great Wall,” in the South China Sea and other regions around the Chinese coast. The networks give it a much better ability to detect enemy submarines, according to Chinese military and academic texts.
The People’s Liberation Army, as China’s military is known, is getting better at finding enemy submarines by adding patrol aircraft and helicopters that pick up sonar information from buoys in the sea. Most of China’s navy now has the ability to deploy underwater listening devices called hydrophones on cables trailing ships or submarines.
In August, China conducted a submarine-hunting exercise lasting more than 40 hours in the South China Sea, involving dozens of Y-8 anti-submarine patrol aircraft. A few weeks earlier, the Chinese and Russian navies conducted a joint anti-submarine warfare exercise in the Bering Sea, off the coast of Alaska
 

Users who are viewing this thread

Back
Top