BEIJING, Oct. 15 (Xinhua) -- A 16th satellite will be added to China's indigenous satellite navigation system, Beidou, within this month, paving the way for the network to provide services to the Asia-Pacific.
A report in the Beijing News on Monday quoted Guo Shuren, a core member of the China Satellite Navigation System's development team, as saying that the system is expected to start providing free services to civilian users in the Asia-Pacific region in the first half of 2013.
China has successfully launched five satellites for Beidou this year in an effort to eventually weave a constellation of 35 satellites by 2020, at which point it could rival the U.S. Global Positioning System (GPS) and Russia's Global Navigation Satellite System (GLONASS) for services around the Earth.
So far, the Beidou system has a total of 15 satellites, five in geostationary orbit, five in inclined geostationary orbit and five in medium Earth orbit, according to the management office.
Ran Chengqi, spokesman and director of the office, said in December last year that six more satellites will be launched in 2012 to further improve Beidou and expand its service area to cover most parts of the Asia-Pacific.
Since it started to function on a trial basis on Dec. 27, 2011, Beidou has been stable and its services have been increased and improved, said a spokesman of the office on Sept. 19 after the successful launch of the 14th and 15th satellites.
The 16th will probably be launched in the last 10 days of October, according to the Beijing News report.
China started to build up its own space-based Positioning, Navigation and Timing (PNT) system in 2000 by launching the first satellite for an experimental version of the Beidou.
Beidou has since started providing licensed services for China's government and military users in transport, weather forecast, fishing, forestry, telecommunications, hydrological monitoring and mapping, according to the spokesman.
However, it is estimated that more than 95 percent of navigation terminals sold in China are GPS terminals.
To compete with foreign rivals, the Beidou terminal can communicate with the ground station by sending and receiving short messages, 120 Chinese characters in each, in addition to the navigation and timing functions that the world's other major navigation systems can provide.
During relief efforts after the 8.0-magnitude earthquake that hit China's southwest in 2008, the system's messaging role helped rescue teams keep smooth contact with each other and the headquarters.
According to the management office, Beidou's free service will be able to track locations within an accuracy of 10 meters, measure speeds within 0.2 meters per second and synchronize clocks with an accuracy of 10 nanoseconds.
Liao Chunfa, a veteran researcher of navigation satellite system, said the space-based PNT system is an essential strategic resource for a country and China should in no way rely on foreign systems in the long term and must develop Beidou unswervingly.
At the same time, Beidou is compatible and interoperable with GPS, the EU's Galileo system and Russia's GLONASS. According to Guo, Beidou's terminals for civilian users will be compatible with GPS.
"To ensure national security and meet the demand of access to services at any location on the planet, China should also develop alternative PNT systems as backups for the Beidou system," Liao suggested.