A study of multi-frequency GNSS ionospheric scintillations at Guilin, China

The features of GNSS ionospheric scintillations were studied by using multi-frequency GNSS measurements at Guilin, China (25.29°N, 110.33°E; geomagnetic: 15.04°N, 181.98°E), a station located near the northern crest of the equatorial anomaly. The results are presented for data recorded by a GPStation6 receiver from July 2015 to June 2016. The results show that amplitude scintillations were observed at night, and they mainly took place in September, October and November of 2015. However, few scintillation events occurred in 2016. The influence of ionospheric scintillations on different frequency GNSS signals is different. It is found that the new civilian signals L2C (1.2276 GHz) and L5 (1.17645 GHz) are more adversely affected than L1C/A (1.57542 GHz) signal during scintillations. And the influence of scintillations on L2C and L5 signals is similar. Ionospheric scintillations are more likely to cause L2C and L5 signals to lose phase lock. Moreover, nighttime scintillations always occurred with TEC (Total Electron Content) depletions. And the variation tendencies of TEC obtained from two different carrier phase combinations (namely, L1C/A and L2C, L1C/A and L5) are same.