基于GNSS的武汉区域电离层TEC建模

为研究适用于区域电离层总电子含量(total electron content, TEC)建模的方法和估计策略，对传统单层假设下的几种建模方法和估计策略进行了比较分析. 基于我国中纬度武汉地区17个连续运行参考站的数据进行TEC建模，建模方法分别采用4×3阶多项式模型、2阶多项式模型、4阶球谐级数模型，估计策略使用分段常数估计策略和分段线性估计策略. 在传统单层假设的基础上，本文还提出了三层电离层TEC模型，该模型可以分别给出底部电离层、峰高电离层和顶部电离层的TEC. 研究结果表明，几种模型的天顶方向总电子含量拟合效果和欧洲轨道确定中心公布的电离层格网地图均具有较好的一致性，其中4阶球谐级数模型和分段线性估计策略效果最佳. 通过三层电离层模型，可以得到TEC与电离层高度之间的关系，多层电离层模型对空间目标监视和低轨卫星航天测控具有重要应用价值.

Modeling of ionospheric TEC around Wuhan based on GNSS

In order to study the methods and estimation strategies applicable to the regional ionospheric total electron content(TEC) modeling, this paper compares and analyzes several modeling methods and estimation strategies under the traditional single-layer hypothesis. Based on the data of 17 continuously operating reference stations in the middle latitudes of my country, the TEC modeling is carried out. The modeling methods used 4×3 polynomial model,2 nd order polynomial model, 4 th order spherical harmonic series model, and the estimation strategy used piece-wise constant estimation strategy and piece-wise linear estimation strategy. On the basis of the traditional single-layer assumption, this paper also proposes a three-layer ionospheric TEC model, which can respectively give the TEC of the bottom ionosphere, peak height ionosphere and top ionosphere. The research results show that, the fitting effect of the total electron content in the zenith direction of several models is in good agreement with the ionospheric grid map published by the European Orbit Determination Center. Among them, the 4 th order spherical harmonic series model and the piece-wise linear estimation strategy have the best effect. Through the three-layer ionospheric model, the relationship between the TEC and the ionospheric height can be obtained. The multi-layer ionospheric model has important application value for space target monitoring and low-orbit satellite aerospace measurement and control.