Accuracy assessment of ionospheric scintillation monitoring in high-latitude regions of the northern hemisphere utilizing geodetic GNSS receivers based on ROTI and AATR

Currently, the 25th solar cycle has entered a period of high activity that can trigger numerous ionospheric irregularities, which in turn lead to ionospheric scintillation on the signals of GNSS. This has become a significant source of interference affecting the stable positioning navigation and timing services of GNSS. It is crucial to conduct extensive and comprehensive monitoring of global ionospheric scintillation to mitigate its adverse effect on GNSS. However, the limited distribution of traditional ionospheric scintillation monitoring receivers (ISMR) cannot meet the requirement of global scintillation monitoring. Geodetic receivers are widely deployed, but the reliability of their scintillation monitoring is questionable due to the lack of validation with long-term and low-sampling data from the new solar cycle. To address this issue, this study compares the accuracy of two ionospheric scintillation indices, i.e. Rate of total electron content change index (ROTI) and along arc total electron content rate index (AATR) in monitoring ionospheric scintillation in the high-latitude Arctic region, based on geodetic receiver data from the past three years and the scintillation factors provided by ISMR as a reference. The study assesses their performance in terms of the following aspects, e.g. the scintillation response to representative space weather events, daily scintillation occurrence rates, probability distribution of scintillation duration, daily occurrence patterns of scintillation, and characteristic 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 indicate that both ROTI and AATR can accurately detect regional ionospheric scintillation driven by geomagnetic disturbances and solar activity. They effectively characterize the daily variations in ionospheric scintillation statistically. However, these two scintillation indices cannot accurately differentiate between scintillation and changes in ionospheric electron density gradients, leading to higher false alarms during periods of drastic changes in electron density gradients. The findings of this study provide guidance for accurately selecting ionospheric scintillation monitoring factors in specific regions. © 2024 SinoMaps Press. All rights reserved.