China's First IPS Observation Telescope Operates

Standing in a vast prairie in Inner Mongolia autonomous region in north China, the main station of the country's first interplanetary scintillation (IPS) observation telescope closely watches the sun with high detection sensitivity.

Guarding against 'space bombs'

IPS refers to radio signals emitted by distant cosmic ray sources. As these signals traverse the solar system, their paths are disrupted by the uneven solar wind, causing rapid, irregular fluctuations in the signals received on Earth — much like stars blinking in space, Yan Yihua, chief scientist of the telescope, explained. "It's similar to seeing distant lights through turbulent air, where the brightness flickers."

The primary purpose of IPS monitoring is to conduct space weather research and disaster forecasting, Yan said. Possessing immense destructive power, violent solar storms are like "space bombs." They can cause satellite damage, communication disruptions, navigation errors and power grid failures — posing significant risks to national security and critical civilian infrastructure. Therefore, enhanced monitoring and space weather forecasts are imperative.

To accurately predict when solar storms will reach Earth and their impact, the speed, density and structural changes of the solar wind and the disturbances it carries through interplanetary space have to be gauged, Yan said. "IPS monitoring is a crucial method for obtaining this vital information."

How it works

Nicknamed the Prairie Sky Eye, the telescope is a major facility of Phase II of the Meridian Project, a national scientific infrastructure in China's space weather field.

The telescope system consists of a main station and two auxiliary stations, all located in Xilingol League in Inner Mongolia, approximately 200 kilometers apart, forming an equilateral triangle.

The main station consists of three rows of parabolic-cylindrical antennas, each row measuring 140 meters north-south and 40 meters east-west. "Together, they form China's largest parabolic-cylindrical radio telescope to date," Wang Wei, senior engineer at the National Space Science Center (NSSC) of the Chinese Academy of Sciences, said.

The parabolic-cylindrical design of the main station's antennas overcame the limitations of traditional parabolic telescopes, reducing construction costs by 60 percent while maintaining equivalent sensitivity.

Each row of antennas has 600 feed units, commonly referred to as signal reception modules. These units receive cosmic radio signals reflected and focused by the parabolic cylinder, then transmit them to back-end equipment for data analysis. The main station telescope has achieved breakthroughs in key technologies such as antenna array coordination, electronic scanning and data synchronization.

The main station functions like a wide-spanning net, responsible for broad-area monitoring whereas the two auxiliary stations, like identical twins in appearance and capability, conduct in-depth observations of particularly active solar phenomena based on clues provided by the main station, explained Fan Jin, senior engineer at NSSC. "Through joint observations, researchers can directly calculate data such as solar wind velocity."

Exceptional performance

Unlike traditional radio telescopes that can receive signals only from specific directions, the Prairie Sky Eye can simultaneously capture signals from multiple directions. "Its detection sensitivity is extremely high, capable of detecting cosmic radio signals across multiple frequency bands that are a hundred billion times weaker than mobile phone signals," Fan said.

Engineering test results have confirmed that the telescope possesses continuous detection capabilities for IPS signals. All technical indicators for the main station and two auxiliary stations meet or exceed the design requirements. The main station's key performance metrics—including antenna aperture, noise temperature and detection sensitivity—are of internationally leading standards.

The telescope covers wide fields of view and large sky regions continuously by integrating east-west mechanical scanning with north-south electronic scanning technology and employing phased-array feed digital multi-beam reception. It can monitor most of the visible sky in the northern hemisphere, with a receiving area six percent larger than the world's largest comparable telescope's.

By telemetering interplanetary solar wind velocity daily, the telescope captures the dynamic propagation of solar wind through interplanetary space. This provides raw observational data and quantitative numerical forecast products for both China's and international space weather forecasting, so that the impact of space weather hazards on critical infrastructure such as aerospace, satellite communications, navigation systems, and power grids can be mitigated, according to Fan.

Since its commissioning, the telescope has demonstrated exceptional performance. For instance, it successfully recorded the intense solar storm in May 2025, showcasing its capability for rapid, high-precision monitoring of space weather events.

Yan said they will dedicate efforts to tracking the entire propagation of solar storms from Sun to Earth, contributing Chinese wisdom to the global effort to jointly address space weather hazards.

Source: Science and Technology Daily