China's BeiDou and Fengyun Satellites Elevate Global Weather Forecasting Capabilities

China's BeiDou and Fengyun Satellites Elevate Global Weather Forecasting Capabilities
by Simon Mansfield
Sydney, Australia (SPX) Nov 16, 2023
In a significant step for space-based weather forecasting, China's BeiDou Navigation Satellite System (BDS) has emerged as a pivotal player. Sun Yueqiang, the director of the Key Laboratory for Space Environment Exploration at the National Space Science Center under the Chinese Academy of Sciences, and also the deputy chief designer of the Fengyun-3 satellite, recently shared insights into the sophisticated interplay between BDS and weather prediction technologies.

Sun explained, "When the BDS satellite works, the signal passing through the Earth's ionosphere and atmosphere will be delayed and bent, producing errors." However, by precisely determining the locations of the BDS and Fengyun satellites, these signal errors can be transformed into valuable data. "Through an inversion processing of the signal error values, we can retrieve the parameters of the Earth's ionosphere and atmosphere, which can be applied to meteorological and space weather monitoring and forecasting," Sun elucidated.

This groundbreaking technique, known as radio occultation, has been perfected over years, overcoming numerous technical challenges. By equipping a Fengyun satellite with a Global Navigation Satellite System signal receiver, the system can now gather atmospheric profiles equivalent to the data from over 1,000 sounding balloons released worldwide. This data is crucial, as it can be transmitted to the numerical weather prediction center within three hours, substantially enhancing the accuracy of weather forecasts.

Sun's innovative work extends beyond China's borders. The data gathered by her team is also contributing to international weather forecasting efforts, being assimilated into systems such as the European Center for Medium-Range Weather Forecasts and other international numerical weather prediction systems in Germany, Canada, the United Kingdom, Japan, among others. This integration underscores the advanced level of China's independently innovated detection technology in the radio occultation field.

Sun's contributions to space environment exploration in China are far-reaching. She has led her team through several key technological breakthroughs in areas such as space particle detection, short-wave optics, and deep-space environment detection. The equipment developed by Sun's team is a critical component of numerous Chinese satellites, playing a vital role in major space projects like Tianwen, Chang'e, and the Tiangong space stations.

One notable achievement is the lunar surface neutron and radiation dose detector on the Chang'e-4 mission. In collaboration with German scientists, Sun's team developed this detector, revealing that lunar surface radiation levels are 200 to 300 times higher than on Earth. This discovery is pivotal for designing radiation-proof equipment for future manned moon missions.

Moreover, Sun's team achieved a milestone in plasma imaging detection on China's space station, providing vital data to safeguard astronauts from high-energy particle radiation during spacewalks.

In recent years, Sun has focused on advancing BDS/GNSS remote sensing technology. Her team successfully used the reflected signal of BDS/GNSS for sea-surface wind speed detection, marking a world-first in the operational application of this technology for numerical weather prediction. This technique has applications in monitoring ocean gravity, soil moisture, and sea ice.

In a collaborative endeavor, Sun's team has partnered with the University of Graz in Austria and the German Research Centre for Geosciences to establish the International Laboratory on Climate and Atmosphere Research with Occultation and Reflectometry Observing Systems. This collaboration aims to create a global shared GNSS remote sensing climate database, develop new GNSS remote sensing technology, and further GNSS meteorology development.

Sun Yueqiang's vision for space environment exploration is expansive and forward-looking. "Space environment exploration is essential to exploring the Universe," she remarked. Her aspiration is to enhance BDS's role in remote sensing detection and to contribute significantly to global climate change research, reflecting a commitment to advancing both China's and the world's understanding of our planet and beyond.