A state-owned engineering firm has successfully used China's home-grown Beidou navigation satellites to help collect upper-atmosphere weather data, another step towards ending the country's dependence on US-controlled GPS technology.
The Beidou system developed by Beijing Changfeng Microelectronics Technology helps pinpoint the location of radiosonde equipment on weather balloons, allowing for accurate meteorological analysis without using foreign systems.
Although the breakthrough would benefit civilian and military users, satellite experts said the People's Liberation Army would remain dependent on the Global Positioning System to provide accurate navigation data for its weapons systems for the time being.
Nevertheless, Beijing Changfeng, a subsidiary of China Aerospace Science and Industry Corporation (Casic), told the Beijing Daily that its radiosonde system - which collects atmospheric data - provided more accurate data than equipment using GPS alone. The company said its radiosonde system, which also supports GPS, was able to detect temperatures in the upper atmosphere more than 0.5 degrees Celsius more accurately than existing models.
Beijing Changfeng is developing civilian applications for the Beidou system, which China has been developing over the last decade and aims to complete by 2020. The system began serving some customers in the Asia-Pacific region last year.
"For years, both our civilian and military radiosonde systems have relied on the GPS system to collect meteorological data," Beijing Chanfeng engineer Peng Wenwu told the Beijing Daily. "But there is a risk that we might detect nothing if the GPS system was shut down as it is still a foreign technology."
Professor He Qisong , a satellite expert at Shanghai University of Political Science and Law, said the PLA has been concerned about its use of American satellite navigation data since 1996, when it was "humiliated" by the US and failed to control missiles fired into the East China Sea during a diplomatic row with Taipei.
A PLA senior colonel confirmed the story, saying that Beijing later realised the US army "had played tricks on its GPS service that it provided to the PLA", which convinced Beijing to develop the Beidou system.
But He said the radiosonde system represented only a modest gain in the country's effort to break its dependence on GPS, and Beidou still had far to go.
"The Beidou-leading radiosonde system developed by Casic is just a small breakthrough in the civilian sector," He said.
Professor Jiao Weixin , of Peking University's School of Earth and Space Sciences, said that GPS provides different systems to its military and commercial clients. Only military clients can share pinpoint positioning and navigation data, while civilian customers use less specific navigation codes.
"So far, the Beidou radiosonde system can only help meteorologists save time and manpower when collecting weather data," Jiao said. Currently, meteorologists must use radar to confirm temperature, humidity, wind speed and other factors affecting weather.