156 / 2023-08-29 19:39:29

Statistical and case investigation on the scintillation monitoring performance of AATR and ROTI in the high-latitude region during the 25th solar cycle

Global Navigation Satellite System; ionospheric scintillation; phase scintillation index; geodetic receiver

    Currently, the 25th solar cycle is in a phase of high activity, resulting in the generation of significant ionospheric irregularities that cause ionospheric scintillation in signals transmitted by the Global Navigation Satellite Systems (GNSS). This has become a significant source of interference affecting the stability of global GNSS navigation and positioning services. It is crucial to conduct extensive and comprehensive monitoring of global ionospheric scintillation to mitigate its impact on GNSS interference. However, the limited distribution of traditional Ionospheric Scintillation Monitoring Receivers (ISMR) cannot meet the requirements of global scintillation monitoring. Geodetic receivers, on the other hand, are widely deployed but lack long-term validation during the new solar cycle to ensure the reliability of scintillation monitoring based on their low-sampling data. To address this issue, this study utilizes nearly three years of data from geodetic receivers during the new solar cycle and references scintillation indices provided by ISMR. The study comparatively investigates the accuracy of two scintillation indices derived from geodetic receivers: the Rate of Total Electron Content Change Index (ROTI) and the Along-Arc Total Electron Content Rate Index (AATR) for monitoring ionospheric scintillation in high-latitude regions. The study assesses their performance in terms of response to representative space weather events, daily occurrence rate, probability distribution of scintillation duration, occurrence patterns, and variations with polar day, polar night, and geomagnetic indices. Additionally, empirical thresholds for ROTI and AATR are provided to determine the occurrence of scintillation in high-latitude regions. The results demonstrate that both ROTI and AATR can accurately detect regional ionospheric scintillation caused by geomagnetic disturbances and solar activity. They effectively capture the statistical diurnal variations of ionospheric scintillation. However, neither index can accurately differentiate scintillation from variations in ionospheric electron density gradients, leading to higher false alarms during periods of intense electron density gradient changes. These findings offer guidance for the appropriate selection of scintillation monitoring indices in specific regions.