The project team led by Zheng Xiaoping, a professor with Tsinghua University’s department of electronic engineering, said it had built a radar capable of tracking 10 incoming hypersonic missiles at Mach 20 with unprecedented precision, and it could also identify false targets.
During ground-based simulations, the new radar showed an error of 28cm (11 inches) in estimating the distance of a missile travelling at nearly 7km (4.3 miles) per second, and it was up to 99.7 per cent accurate when estimating the missile’s speed, the team said of a feat previously thought to be impossible.
Generating and analysing radar signals with precision for measurement requires electrons to move at extremely high speeds, which can potentially burn out the circuit boards.
However, Zheng’s team innovated by incorporating lasers into the radar, enabling information transmission between key nodes to reach the speed of light.
As a result, the radar system could generate and process microwave signals much more complex than before, precisely measuring ultra-high-speed objects for the first time.
This new microwave photonic radar boasts a detection range of over 600km, Zheng and his collaborators from Guangxi University said in a peer-reviewed paper. It was published on May 24 in the Chinese-language journal, Optical Communication Technology.
The microwave photonic radar is small and light, making it suitable for loading on to air-defence missiles or planes. It is considered by some military experts to be key technology for the next generation of fire-control radars.
The United States, which strives to narrow the gap with China in hypersonic weapons, tested an air-launched hypersonic missile on Guam in the Western Pacific in March.
This test was perceived by some Western military observers as a targeted response to China, showing the US military’s ability to attack Chinese coastal cities with its high-penetration weapon.
Hypersonic weapons pose a greater challenge for interception than traditional ballistic missiles. They are not only faster, but can make unpredictable manoeuvres, enabling them to penetrate air-defence networks.
While new interceptor missiles and laser weapons have the potential to destroy incoming hypersonic weapons, they require precise target position and velocity parameters to succeed.
According to a report released last year by the Centre for Strategic and International Studies (CSIS), a Washington-based think tank, one of the most vexing issues for the Pentagon is the challenge to obtain a fire-control radar that can track hypersonic targets with high precision for interceptor missile systems.
“If you have more precise data, you could use an interceptor that maybe wouldn’t need to manoeuvre as much, and could be cheaper,” said Masao Dahlgren, the report’s author with the CSIS Missile Defence Project, in an interview with spacenews.com in December.
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Chinese hypersonic weapons test ‘has all of our attention’, US General Mark Milley says
Chinese hypersonic weapons test ‘has all of our attention’, US General Mark Milley says
Another challenge posed by high-speed moving targets is the emergence of phantom images on radar screens, with “false targets” often outnumbering real targets.
Using laser technology, Zheng’s team enabled the radar to send three different bands of microwaves simultaneously, improving detection accuracy. They also developed an algorithm that eliminates false target interference entirely by comparing signals of different frequencies.
Zheng and his team have built a complete radar system, including chips and transmitters, verifying the performance in a laboratory with instruments that simulate the movement of hypersonic targets in the atmosphere.