The fourth navigation satellite in China’s Beidou or Compass constellation was successfully launched on June 2, 2010.  This satellite is one of five planned geostationary satellites that will ultimately provide navigation coverage within the Asia-Pacific region.  An additional thirty non-geostationary satellites are expected to be in place by 2020 in order to bring the Compass constellation to full global coverage similar to what is currently provided by the GPS constellation. China is planning to have a total of twelve satellites in orbit by the end of 2012 to provide positioning, timing and short messaging communication services for much of Asia and the Pacific region.  The system is expected to provide a positioning accuracy of approximately thirty feet for civilian users.  A more accurate service will be available to authorized and military users only. 

 Once all currently planned satellites have been deployed and added to those already in orbit in existing constellations, it is anticipated that positioning services, particularly in “urban canyons” and other locations where signal strength has previously been an issue, will be significantly enhanced for navigation system users around the world.

The Compass Navigation Satellite System will initially provide service to the Asia-Pacific region (public domain image courtesy of Wikimedia Commons).