State media say the 14th and 15th satellites in the Beidou system were launched aboard a single Long March 3B rocket early Wednesday. The system, whose name means compass in English, is due to have 35 satellites in total by its 2020 completion date.
The system already provides coverage over much of Asia, with at least one more satellite set for launch this year. China expects Beidou to generate a 400 billion yuan ($63 billion) annual market for services to the transport, meteorology and telecommunications sectors.
The system's military implications are just as important, freeing China from having to use GPS for tasks such as missiles guidance.