Latest news with #JournalofHarbinEngineeringUniversity
South China Morning Post
29-04-2025
- Science
- South China Morning Post
China is developing an ‘Underwater BeiDou' network for navigation and tracking
China is developing an ambitious undersea network to improve navigation, provide real-time environmental monitoring, and potentially track submarines and drones. Advertisement The sprawling network of floating and submerged buoys and sea floor nodes is a bid to expand Beijing's maritime influence but also fill the gaps in existing underwater observation systems. Dubbed the 'Underwater BeiDou' – China's satellite navigation system – the project is being spearheaded by the Ministry of Natural Resources. 01:23 China launches last piece of BeiDou Navigation Satellite system into orbit China launches last piece of BeiDou Navigation Satellite system into orbit While it is not known what stage the project is at, the ministry has revealed that large-scale prototypes have been built and tested. Its research team disclosed details of the project in a peer-reviewed paper in the Journal of Harbin Engineering University in February. According to the paper, the network will be based on surface buoys, submerged buoys and seabed platforms. Advertisement Surface buoys, equipped with multiple satellite receivers, will provide real-time data via encrypted links. Mid-depth submerged buoys will be used to track water currents and salinity shifts using acoustic profilers.
South China Morning Post
07-02-2025
- Science
- South China Morning Post
China can detect US Seawolf-class submarine with magnetic wake tracking: study
Published: 2:00pm, 7 Feb 2025 For US submarines operating in waters near China, the era of absolute stealth may be ending – one magnetic ripple at a time. Researchers with Northwestern Polytechnical University (NPU) in Xian claim to have developed a groundbreaking method to detect even the quietest underwater vessels by harnessing the magnetic fields generated by their wakes – a discovery that could reshape naval warfare. Led by associate professor Wang Honglei, the team modelled the Kelvin wake, a V-shaped surface disturbance created by submarines as they slice through water. This wake, previously studied for radar-based imagery detection, generates a faint but detectable magnetic field when seawater ions – disturbed by the vessel's motion – interact with Earth's geomagnetic field. Using numerical simulations, the researchers quantified how these magnetic signatures vary with a submarine's speed, depth and size. For example, increasing speed by 2.5 metres per second (8.2 feet per second) boosts magnetic intensity tenfold; reducing depth by 20 metres (66 feet) doubles the field strength; and longer submarines produce weaker fields, while wider hulls amplify them. For a Seawolf-class submarine travelling at 24 knots (12.5 metres per second) and 30 metres (98 feet) depth, the wake's magnetic field reaches 10⁻¹² tesla – 'well within the sensitivity range of existing airborne magnetometers,' according to Wang and his colleagues. The team's method, which was detailed in the peer-reviewed Journal of Harbin Engineering University on December 4, exploits a critical vulnerability: 'Kelvin wakes cannot be silenced.'
