Chinese President Xi Jinping attended a ceremony to mark the launch of the BeiDou-3 Navigation Satellite System on Friday in Beijing, announcing that China's self-constructed and independently operated global navigation satellite system has been fully completed.

The BeiDou Navigation Satellite System, or BDS, is China's largest space-based system and one of the four global navigation networks, alongside GPS of the U.S., Russia's GLONASS and the European Galileo.