Transmissions from Global Navigations Satellite Systems (GNSS), including the Global Positioning System (GPS), GLONASS and Galileo, provide positioning and navigation services. The car satnav is perhaps the best known example, but ship and aircraft navigation, tracking of products and deliveries and emergency service dispatch are all increasingly dependent on the GNSS position and navigation services. GNSS also provides very accurate (tens of nanoseconds) timing services. Some telecommunications services use timing signals from GPS satellites to synchronise networks to facilitate data flow and the financial services industry uses GNSS to time stamp transactions in high speed trading.
Amplitude scintillation that causes rapid changes in the carrier-to noise ratio, can lead to loss of carrier tracking in all receivers.
Phase scintillation that sufficiently disturbs the carrier phase causes the receiver phase tracking loop to lose lock impacting the reception of the important navigation data message which includes the satellite empherides. The code tracking loop, that measures range to the satellite, is fairly robust to phase scintillation and usually remains locked.
Loss of phase lock in receivers used in high integrity applications (eg aviation) is particularly important as these receivers need to regularly read the satellite data message. To mitigate this, satellite based augmentation systems (SBAS), such as WAAS and EGNOS, employ a message symbol rate of 500 symbols , together with a rate one-half encoder and repeated messages to deal with burst errors.
Reference : Royal Academy of Engineering, "Extreme space weather: impacts on engineered systems and infrastructure", pp45, Feb, 2013.