A Chinese scientist encourages innovation in space exploration payloads

Sun Yuqiang (center), director of the Key Laboratory for Space Environment Exploration of the National Space Science Center of the Chinese Academy of Sciences, checks key parameters with the Space Exploration Payload Technology Team, November 9, 2023. (National Space Science) Center of the Chinese Academy of Sciences (Release via Xinhua News Agency)

BEIJING, Nov. 14 (Xinhua) — While China’s Beidou navigation satellite system (BDS) provides people with high-precision positioning and navigation, it has also become more important in accurate weather forecasting.

To explain the scientific principles behind this, Sun Yuqiang, director of the Key Laboratory for Space Environment Exploration of the National Space Science Center of the Chinese Academy of Sciences, drew a diagram with Earth in the middle, a Fengyun satellite 800 kilometers away. On one end, and the BDS satellite is about 20,000 kilometers away on the other end.

“When the BDS satellite is working, the signal passing through the Earth’s ionosphere and atmosphere will be delayed and bent, resulting in errors,” said Sun, who is also deputy chief designer of the Fengyun-3 satellite.

“But if we know the exact positions of the BDS and Fengyun satellites, through inverse processing of the signal error values, we can retrieve the ionospheric and terrestrial atmospheric parameters, which can be applied to meteorological and space weather monitoring and forecasting,” she said.

According to the scientist, the Global Navigation Satellite System (GNSS) signal receiver on the Fengyun satellite receives GNSS signals, and the retrieved atmospheric profiles are equivalent to those of more than 1,000 sound balloons launched around the world, and the monitoring data can be transmitted to Digital numbers. Weather forecasting center within three hours.

“After years of efforts, we have overcome many technical difficulties to realize this technology,” she said, adding that this technology, called radio occultation (RO), can provide timely data support for weather forecasting and effectively enhance forecast accuracy.

In addition to China’s weather forecasting service, the data obtained by Sun’s team has also been ingested into the European Center for Medium-Range Weather Forecasts (ECMWF), as well as international numerical weather prediction systems in Germany, Canada, the United Kingdom and Japan. And other countries.

“This shows that China’s independently innovative detection technology in the field of reverse osmosis has reached the world’s advanced level,” Sun said.

As a leading figure in China’s space environment exploration, Sun has been committed to promoting the development of space exploration payload technology.

Over the past years, she has led her team to achieve several major innovative technological breakthroughs in space particle detection, short-wave optics, and deep space environment detection.

So far, various types of environmental detection equipment developed by Sun’s team have formed part of hundreds of Chinese satellites operating in orbit. Many of these have played vital roles in China’s major space projects, such as the Tianwen, Chang’e and Tiangong space stations.

For example, the lunar surface radiation and neutron dose detector on Chang’e-4 obtained a large amount of detection data. The detector, developed by Sun’s team in cooperation with German scientists, found that radiation on the moon’s surface is 200 to 300 times higher than on Earth’s surface, laying the foundation for a radiation-proof design for China’s manned moon landing in the future.

In addition, the detector developed by Sun’s team achieved plasma imaging detection for the first time on the Chinese space station. It provided data support for astronauts to avoid the risks of high-energy particle radiation during extravehicular activities.

In recent years, Sun has led her team to challenge the new frontiers of BDS/GNSS remote sensing technology.

By using the reflected signal of BDS/GNSS to detect wind speed at the sea surface, Sun and her team realized the practical application of numerical weather prediction for the first time in the world. They also applied it to ocean gravity, soil moisture, and sea ice monitoring.

Recently, Sun and her team established the International Laboratory for Climate and Atmospheric Research with occultation monitoring and reflectometry systems together with the University of Graz in Austria and the German Research Center for Geosciences (GFZ) to create a joint global climate database for GNSS remote sensing. , develop new GNSS remote sensing technology, and promote the development of GNSS meteorology.

“Exploring the space environment is essential for exploring the universe,” Sun said.

“I hope to make the Beidou system play a greater role in remote sensing detection, and I hope China will make greater contributions to climate change research,” she added. ■