几种地基GPS区域电离层TEC建模方法的比较及其一致性研究

Comparison and Consistency Research of Regional Ionospheric TEC Models Based on GPS Measurements

利用GPS实测资料实现了中国区域电离层电子含量建模,比较和评估了多项式模型、三角级数模型和低阶球函数模型的监测精度及存在的问题。研究表明,在平静电离层的条件下,多项式模型和低阶球函数模型拟合的精度较好,但前者存在明显的边际效应;三角级数模型在用于大区域拟合时精度较差;高纬度地区模型拟合的精度要优于低纬度地区。根据这些模型参数设置的特点以及电离层本身的变化分布规律,分析了这些差异存在的原因。

TEC information ous-operatlon stations over from 2004 all-year GPS measurements on more than 40 continu China is resolved, these TEC data are modeled by three common ly used regional models, poly model（Poly）, trigonometric series model（TRI） and low-degree spheric function model（LSF）. The results show that Poly and LSF models are consistent with GIM model（CODE）, but the former is degraded by marginal effect, and TRI model have noticeable bias to GIM model, which alarms us this model is not suitable for the region, just for the local. Furthermore, the accuracy on high latitude area is better than that on lower latitude area.