The observations of Global Positioning System(GPS) scintillation,Total Electron Content(TEC)depletion,the periodic structure of TEC and Rate of TEC Index(ROTI) over south China were presented.Data were collected from ...The observations of Global Positioning System(GPS) scintillation,Total Electron Content(TEC)depletion,the periodic structure of TEC and Rate of TEC Index(ROTI) over south China were presented.Data were collected from GPS observations at stations of Shenzhen and Guangzhou from 2011 to 2012.This study reported that the ratio of simultaneous occurrences of TEC depletions with strong scintillations was higher than that of TEC depletions with weak scintillations in vernal and autumnal equinoxes of 2011 over South China.The number of the periodic structures of TEC with depletion contained was greater than that with no depletion contained corresponding to strong scintillations.The structure of the slab of plasma irregularities could be responsible for the simultaneous occurrences of TEC depletion with strong scintillations and ROTI.Before and during the occurrences of strong scintillation,there was Large-Scale Wave Structure(LSWS) which provided the seed ionization perturbation to trigger ESF irregularities and contributed to the periodic structure of TEC.展开更多
The ionospheric effect plays a crucial role in the radio communications. For ionospheric observing and monitoring, the Global Navigation Satellite System (GNSS) has been widely utilized. The ionospheric condition can ...The ionospheric effect plays a crucial role in the radio communications. For ionospheric observing and monitoring, the Global Navigation Satellite System (GNSS) has been widely utilized. The ionospheric condition can be characterized by the Total Electron Contents (TEC) and TEC Rate (TECR) calculated from the GNSS measurements. Currently, GNSS-based ionospheric observing and monitoring largely depend on a global fiducial network of GNSS receivers such as the International GNSS Service (IGS) network. We propose a new approach to observe the ionosphere by deploying a GNSS receiver on a Hong Kong Mass Transit Railway (MTR) train. We assessed the TECR derived from the MTR-based GNSS receiver by comparing it with the TECR derived from a static GNSS receiver. The results show that the Root-Mean-Squares (RMS) errors of the TECR derived from the MTR-based GNSS receiver is consistently approxi-mately 23% higher than that derived from the static GNSS receiver. Despite the increased error, the findings suggest that the GNSS observation on a fast-moving platform is a feasible approach to observe the ionosphere over a large region in a rapid and cost-effective way.展开更多
From Nov. 6 to 10, 2004, a large number of solar events occurred, which triggered many solar flares and coronal mass ejections (CMEs). These CMEs caused two large geomagnetic storms and continuous energy proton events...From Nov. 6 to 10, 2004, a large number of solar events occurred, which triggered many solar flares and coronal mass ejections (CMEs). These CMEs caused two large geomagnetic storms and continuous energy proton events. During this period, one large positive ionospheric storm happened over the East-Asian region on Nov. 8, 2004. On Nov. 10, 2004, a strong spread-F was observed by the ionosonde located in the mid-latitude region of East China and Japan, and the ionospheric fluctuation over the ionosonde stations derived from GPS observation was also obvious. In this report, the characteristics of the spatial distribution of the ionosphere fluctuation and its temporal evolution are studied using the parameter of the rate of total electron content (ROT) derived from dual-frequency GPS measurement. Strong fluctuating activity of the ionosphere was found over the mid-latitude region in the southern and northern hemispheres between longitudes of 100°E and 180°E during the magnetic storm period on Nov. 10, 2004, and a regular movement of the disturbing region was observed. In the end, the reason of the ionospheric fluctuation during this magnetic storm is analyzed.展开更多
基金Supported by the National Natural Science Young Foundation of China(41704168)。
文摘The observations of Global Positioning System(GPS) scintillation,Total Electron Content(TEC)depletion,the periodic structure of TEC and Rate of TEC Index(ROTI) over south China were presented.Data were collected from GPS observations at stations of Shenzhen and Guangzhou from 2011 to 2012.This study reported that the ratio of simultaneous occurrences of TEC depletions with strong scintillations was higher than that of TEC depletions with weak scintillations in vernal and autumnal equinoxes of 2011 over South China.The number of the periodic structures of TEC with depletion contained was greater than that with no depletion contained corresponding to strong scintillations.The structure of the slab of plasma irregularities could be responsible for the simultaneous occurrences of TEC depletion with strong scintillations and ROTI.Before and during the occurrences of strong scintillation,there was Large-Scale Wave Structure(LSWS) which provided the seed ionization perturbation to trigger ESF irregularities and contributed to the periodic structure of TEC.
文摘基于加拿大地区高纬度电离层观测网的电离层闪烁观测数据,分析了2018年8月26日地磁暴事件引发的北半球高纬度地区电离层总电子含量(TEC)异常变化、TEC变化率指数(ROTI)及电离层相位闪烁的变化特征.结果表明:加拿大地区最大异常值约6 TECU,磁暴引发全球电离层TEC异常峰值高达20 TECU;加拿大地区电离层相位闪烁发生率最大增至12.6%,而磁静日期间约为1%;强电离层闪烁期间,电离层相位闪烁指数与ROTI之间具有较强的一致性.对GPS双频精密单点定位(Precise Point Positioning,PPP)结果进行分析发现:无闪烁期间定位误差随测站纬度的增高呈现出增大趋势,但均方根误差小于0.4m;闪烁发生期间各测站的定位误差均显著增大,水平和垂直方向定位误差分别增至约0.9m及1.7m.
基金the Key Program of the National Natural Science Foundation of China(NSFC)project(No.:41730109)is acknowledgedThe grant supports to Zhizhao Liu from the Hong Kong Research Grants Council(RGC)project(B-Q61L PolyU 152222/17E)are thankedThe Emerging Frontier Area(EFA)Scheme of Research Institute for Sustainable Urban Development(RISUD)of the Hong Kong Polytechnic University under Grant 1-BBWJ is also acknowledged.
文摘The ionospheric effect plays a crucial role in the radio communications. For ionospheric observing and monitoring, the Global Navigation Satellite System (GNSS) has been widely utilized. The ionospheric condition can be characterized by the Total Electron Contents (TEC) and TEC Rate (TECR) calculated from the GNSS measurements. Currently, GNSS-based ionospheric observing and monitoring largely depend on a global fiducial network of GNSS receivers such as the International GNSS Service (IGS) network. We propose a new approach to observe the ionosphere by deploying a GNSS receiver on a Hong Kong Mass Transit Railway (MTR) train. We assessed the TECR derived from the MTR-based GNSS receiver by comparing it with the TECR derived from a static GNSS receiver. The results show that the Root-Mean-Squares (RMS) errors of the TECR derived from the MTR-based GNSS receiver is consistently approxi-mately 23% higher than that derived from the static GNSS receiver. Despite the increased error, the findings suggest that the GNSS observation on a fast-moving platform is a feasible approach to observe the ionosphere over a large region in a rapid and cost-effective way.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41174134 and 40904036)the National Basic Research Program of China ("973" Project) (Grant No. 2011CB811405)the State Key Laboratory of Space Weather
文摘From Nov. 6 to 10, 2004, a large number of solar events occurred, which triggered many solar flares and coronal mass ejections (CMEs). These CMEs caused two large geomagnetic storms and continuous energy proton events. During this period, one large positive ionospheric storm happened over the East-Asian region on Nov. 8, 2004. On Nov. 10, 2004, a strong spread-F was observed by the ionosonde located in the mid-latitude region of East China and Japan, and the ionospheric fluctuation over the ionosonde stations derived from GPS observation was also obvious. In this report, the characteristics of the spatial distribution of the ionosphere fluctuation and its temporal evolution are studied using the parameter of the rate of total electron content (ROT) derived from dual-frequency GPS measurement. Strong fluctuating activity of the ionosphere was found over the mid-latitude region in the southern and northern hemispheres between longitudes of 100°E and 180°E during the magnetic storm period on Nov. 10, 2004, and a regular movement of the disturbing region was observed. In the end, the reason of the ionospheric fluctuation during this magnetic storm is analyzed.
