World's top 4 navigation systems

Besides China's Beidou, there are three similar services around the world: the GPS of the US, the Russian GLONASS and the EU's Galileo.

The Global Positioning System, or GPS, was developed by the US in the 1970s and completed in 1994. It is the most widely used navigation system now. GPS provides location and time information in any weather, anywhere on or near Earth.

Russia's GLONASS, or Global Navigation Satellite System developed in 1976, achieved full coverage of Russian territory by 2010. Now the total number of satellites in orbit is 31, and among them, 24 are in operation.

The EU's satellite navigation system is known as Galileo. It is the first navigation system to focus on civilian use, and aims to provide high-precision positioning services for European nations. Galileo is formed of 30 satellites and two ground operations centres.

China has now developed the Beidou Satellite Navigation System. It includes five static and 30 non-static satellites, and its locating precision reaches ten metres. It not only provides navigation, location and timing services, but also a communication service.