BEIJING, Nov. 13 -- China is expected to launch two
navigation satellites early next year as part of a plan to build a global
navigation positioning network, aerospace insiders say.
The launch of the two "Beidou" (Compass) satellites,
scheduled for the beginning of 2007, is expected to cover China and parts of
neighbouring countries by 2008, before being expanded into a global system, the
sources confirmed over the weekend.
The planned network will be a constellation of 35
satellites, including five geo-stationary Earth orbit satellites and 30 medium
Earth orbit satellites, Xinhua News Agency quoted informed sources as saying.
The system will provide two navigation services.
The service open to commercial customers will provide
them with positioning accuracy within 10 metres, speed accuracy within 0.2
metres per second and timing accuracy within 50 nanoseconds.
In addition to the "open" level of service, the
system will also offer safer "authorized" positioning, velocity and timing
To make the country's first-generation navigation
system more compatible with other global satellite navigation systems, China is
willing to co-operate with other countries, the aerospace sources said.
The United States initiated its "Navstar Global
Positioning System (GPS)" in 1973, the world's first GPS service. The former
Soviet Union started launching satellites for its space-based navigation system,
the Global Orbiting Navigation Satellite System (GLONASS), in the early 1980s.
The European Space Agency kicked off its own positing
system, the Galileo Project, in 2002.
China has sent three Compass navigation test
satellites into orbit between 2000 and 2003.
The existing three-satellite Compass navigation
system has played an important role in offering accurate positioning and time
references for sectors including surveying, telecommunications, transportation,
meteorology, forest fire prevention, disaster forecasting and public security.
China imported its first GPS receivers in the 1980s,
and has become a major GPS user.
The China National Space Administration said last
month the country will improve the "Beidou" navigation satellite test system,
and implement the "Beidou" navigation satellite system project.
In listing the major tasks through 2010, China's
Space Activities in 2006, a policy document released by the State Council
Information Office on Oct. 12, said China will "independently develop
application technologies and products in applying satellite navigation,
positioning and timing services."
The country will also set up a standard positioning
service supporting system and popular application terminus related to satellite
navigation and positioning, expanding the application fields and market.
(Source: China Daily)