GPS广播电离层模型精化方法

GPS Broadcast Ionosphere Model Refinement Method

电离层延迟是影响定位的主要误差源之一,与电离层电子含量(TEC)密切相关。Klobuchar模型是GPS单频用户在实时定位中消除电离层延迟的有效方法,其精度在太阳活动低年只有50%～60%。针对TEC时间序列的随机噪声和Klobuchar模型参数设置的局限性采取两种不同的改进策略,以双频修正法计算值作参考,利用广西连续运行参考系统(CORS)监测站数据进行解算并分析不同优化策略的效果,研究表明,针对TEC时间序列的精化模型,Kalman滤波处理策略效果最优,加权最小二乘方法效果最差,该处理策略改进效果整体差于模型参数的估计修正策略;模型参数修正方法以14参数模型修正效果为最优,10参数次之,8参数最差,另外模型的计算效率也是其适用性的考量标准之一。

Ionospheric delay is one of the main error sources affecting the location, which is closely related to the ionospheric electron content (TEC). Klobuchar model is an effective method for eliminating ionospheric delay in real-time positioning of GPS single-frequency users. Its precision is only 50%~60% in low solar activity years. Aiming at the limitation of the random noise of TEC time series and the parameter setting of Klobuchar model, two different improvement strategies are adopted. The results of different optimization strategies are calculated and analyzed with the data of Guangxi CORS monitoring station. The results show that the Kalman filtering strategy for the refined model of TEC time series has the best effect, and the weighted least square method has the worst effect. TEC time series refined strategy is worse than the estimation correction strategy for the model parameters. The model parameters correction method takes the 14-parameter model as the best, the 10-parameter model is the second, and the 8-parameter model is the worest. In addition, the computational efficiency of the model is also one of the criteria for its applicability.