Characterization of Robust Carrier Phase Tracking Techniques under Ionosphere Scintillation Scenarios

Ionospheric scintillations are known to affect both the magnitude and the phase of the incoming GNSS signal. These phase variations are typically synchronized with a deep fade of the signal level, that could lead to the occurrence of cycle slips (phase jumps), errors in the data demodulation and ultimately loss of lock. These effects have an impact not only on accuracy, but also availability, continuity and integrity. This particular aspect is of critical importance since ionospheric scintillations have been identified as one of the causes for integrity faults that need to be detected in safety critical applications. At receiver level, this can be tackled by the use of robust tracking techniques. In particular, the impact on carrier phase tracking is very important as it is more prone to loss of lock, and it is often used to smooth the code measurements, carrier aiding or even Doppler/user dynamics estimation. Moreover, it is through the impact on phase estimation that the data demodulation capability can be assessed, as well as different applications such as ionospheric characterization. This study assesses the behavior of robust carrier phase tracking techniques using both simulated and real data for the ionospheric scintillations. Finally, it introduces an innovative technique and discusses its potential