一种基于GNSS数据的全球电离层不规则结构活动表征方法

针对如何利用GNSS（Global Navigation Satellite System）数据进行电离层扰动监测的问题，提出了一种基于GNSS数据表征全球电离层扰动的方法。利用大约400个GNSS地面站点的观测数据，计算总电子含量（Total Electron Content，TEC）变化率的标准差——ROTI（Rate of TEC Index）。将该计算结果作为扰动观测量，在纬度与经度的网格上投影形成1 h分辨率的ROTI地图。ROTI地图能够体现几千米到几十千米的电离层不规则体，分析2015年3月期间电离层平静和扰动剧烈时ROTI地图发现，这种大尺度的不规则体主要分布在高纬和低纬区域，磁暴期间ROTI地图会出现数值和扰动面积上的变化，ROTI地图在一定程度上能够表现全球电离层不规则结构的扰动。在此基础上提出了新的全球ROTI扰动指数(Global ROTI index, GROTI)，分析结果表明高纬区域的GROTI与地磁指数Kp及AE指数存在良好的相关性。

A Characterization Method of Global Ionospheric Irregularities Activities Based on GNSS Data

For the problem of how to use GNSS (Global Navigation Satellite System) data to monitor ionospheric disturbance, this paper proposes a method for characterizing global ionospheric disturbances based on GNSS data. This article uses GNSS (Global Navigation Satellite System) observations of approximately 400 ground stations to calculate the standard deviation of the rate of change of TEC (Total Electron Content)–ROTI (Rate of TEC Index, ROTI), as an ionospheric disturbance observation and projected onto a grid of latitude and longitude to form a 1-hour resolution ROTI map. ROTI maps can reflect ionospheric irregularities ranging from several kilometers to tens of kilometers. The article analyzes the results of ROTI maps when the ionosphere is calm and disturbed during March 2015. And results show that such large-scale irregularities are mainly distributed in high latitude and low latitude regions. During a magnetic storm, ROTI maps show changes in numerical values and disturbance areas. ROTI maps can represent global ionospheric disturbances to a certain extent. On this basis, the index of Global ROTI Disturbance (Global ROTI index, GROTI) is proposed and the analysis results show that GROTI in high regions has a good correlation with the geomagnetic index Kp and AE index.