Extracting ionospheric phase scintillation indicator from GNSS observations with 30-s sampling interval in the high-latitude region

Ionospheric scintillation affects the positioning, navigation and timing services of the Global Navigation Satellite System (GNSS), calling for an urgent need for scintillation monitoring on a global scale. To monitor the ionospheric scintillation with each carrier of the 30-s sampling interval GNSS observations, a scintillation extraction method is proposed based on the Morse wavelet transform, together with the determination of the symmetry parameter, the time-bandwidth product, the characteristic frequency range and the threshold of the scintillation. After testing with four-year observations collected at 15 middle- and high-latitude stations, results show that the extracted scintillation indicator can detect the occurrence but fails to provide the magnitude of the scintillation with the 30-s-sampling-interval observations. Compared to the state-of-the-art scintillation index extracted from the ionospheric scintillation monitoring receiver, the proposed scintillation indicator is applicable in utilizing 30-s sampling interval GNSS observations to monitor scintillations in high-latitude regions, especially for those with long durations, hence making the widely available GNSS observations with low sampling intervals be introduced into the field of ionospheric scintillation monitoring on a global scale.