Study Of Ionospheric Scintillation Based On BeiDou GEO Satellite

The ionosphere is an important protective layer for human development.Disturbances in the ionosphere lead to changes in the electron content,which affects the propagation of wireless signals and thus people’s daily lives.Ionospheric scintillation is one of the main manifestations of ionospheric disturbances,and the occurrence of scintillation will affect the reliability of satellite navigation systems and communication systems.Therefore,the study of ionospheric scintillation has important theoretical and practical value.In this paper,the geostationary orbit(GEO)satellites of the Beidou satellite navigation system are used to analyze and study the ROTI(Rate of TEC Index)index.The characteristics of ionospheric scintillation are analyzed by three experiments,and a distinction is made between scintillation events under geomagnetic calm days and those under the occurrence of magnetic storms.The main work and results of this paper are as follows.(1)The theoretical background of ionosphere and ionospheric scintillation is introduced systematically,mainly including the stratification and monolayer hypothesis of ionosphere,the classification of ionospheric scintillation,and the correlation between ROTI and scintillation.(2)Using Bei Dou GEO satellite data,ionospheric scintillation at low latitudes from 0°-180°E was studied in 2017-2018.The results show that the ionospheric scintillation at low latitudes varies significantly with the season,with the number of scintillations in spring and autumn being comparable and both greater than those in winter and summer.The presence of locally generated and drifting plasma bubbles in the near equatorial region leads to the occurrence of scintillation events.(3)Ionospheric scintillation at low and mid-latitudes in China during the September 2017 magnetic storm was investigated by using observations from the Crustal Movement observation Network of China(CMONOC)and observations from the i GMAS measuring station Beidou GEO.The results show that the scintillation events at low and middle latitudes in China during the magnetic storms all occur at night.Scintillation events appear first at low latitudes,derive widely to the northwest,and eventually disappear.Within the middle and low latitudes of China with longitudes less than 112°E,there are more scintillation events in areas with large longitudes and low latitudes than in areas with small longitudes and high latitudes.(4)The Kunming ionospheric scintillation phenomenon during the September2017 magnetic storm at low latitudes was further investigated using Beidou GEO observations from the CORS station in Kunming,Yunnan Province.The results show that the scintillations appear instantaneously and last for more than 6 hours during the magnetic storms,and the derivation speed is fast and covers almost the whole Kunming city;the scintillations begin to appear in the southeast corner of Kunming city and are derived in the northwest direction,and the derivation trajectory is consistent with the scintillations in the middle and low latitude regions of China;in Kunming city,the scintillations appear earlier in areas with large longitudes than those with small longitudes at similar latitudes,and the scintillations appear in areas with small longitudes at small differences.In the case of small differences in longitude,the scintillation appears earlier at low latitudes than at high latitudes.