Dr Yuang Yang from the China National Administration of GNSS Applications (CNAGA) says Chinese policy on the international use of Compass is being guided by twin principals of openness and interoperability.
He told the International GNSS Society conference on the Gold Coast in Australia that the open signal from the Compass system will be free, and the Chinese government will encourage users around the world to use the system.
The first Compass birds - three geostationary satellites - were lofted in 2002. Enough satellites to populate a regional GNSS over China will follow next year and in 2011. Full global coverage will occur by 2020.
However, users outside China still have quite a wait before the compass signal is likely to rival GPS.
Apart from the the obvious fact that receivers will not begin to flow from manufacturers until a signal from space is available, the Chinese system will use the CTRF reference frame.
Currently, this frame is based on observations from 28 CORS network stations in China. The position of these stations relative to GPS, and thus to WGS84, is known to within millimetres. There are a further 2500 stations, also on the Chinese mainland, whose position is known at the centimetre level.
However, there are no stations outside China. Furthermore, the Chinese have yet to announce monitoring stations for the Compass system outside China. Establishing these will be necessary steps before international use of the network is possible.
Yang also clarified that the short message service that currently exists on the geostationary Compass satellites will be freely available to registered users world-wide when global constellation is established.
This system makes it easy to establish remote monitoring networks. For instance, compass has been used to establish a national water monitoring network, in which compass receivers have been tied to flow meters on rivers in China, and data transmitted back to a central control office.
