Global satellite navigation has joined weather observation and communications via satellites as a space based service that is taken so totally for granted, most of the public don’t even know that space is involved. Satellite navigation will become increasingly robust as two new systems join the operational American Global Positioning System (GPS) and Russian GLONASS.
The Chinese Beidou Navigation Satellite System is now being activated and will be globally available by the end of the decade: Beidou to cover world by 2020 with 30 satellites – Xinhua | English.news.cn.
Activation of the European Galileo system is also underway and will be completed by 2019.
So by 2020, many navigation devices should be able to work with all four systems and always have multiple satellites in view. This will be important for aviation where highly reliable navigation is crucial, especially when routes are selected for optimum fuel consumption rather than according to limited fixed lanes set by ground navigation systems.