小波分解与Prophet框架融合的电离层VTEC预报模型

Ionosphere VTEC prediction model fused with wavelet decomposition and Prophet framework

在全球导航卫星系统(global navigation satellite system,GNSS)的应用中,电离层垂直总电子含量(vertical total electron content,VTEC)是直接决定电离层延迟误差的重要参数。为提高其短期预报精度,在综合考虑地磁扰动影响的基础上,提出了小波分解与Prophet框架融合的时间序列预报模型,并基于全球电离层模型(global ionosphere model,GIM)格网数据进行了对比实验。通过均方根误差、平均绝对误差、平均绝对百分比误差3项指标评估了预测结果,并分析其预报残差。结果表明在不同条件(电离层平静期与活跃期)下,该模型的预报精度均较高,优于未改进的Prophet框架,显著优于自回归移动平均(autoregressive integrated moving average,ARIMA)模型,在中、高纬度地区有良好的适用性。

In the application of global navigation satellite system(GNSS),the ionosphere vertical total electron content(VTEC)is an important parameter that directly determines the ionosphere delay error.In order to improve its short-term prediction accuracy,a time series prediction model fused with the wavelet decomposition and Prophet framework is proposed on the basis of considering the influence of geomagnetic disturbance.The comparative experiments are carried out based on the global ionosphere model(GIM)grid data.The indicator of root mean square error,mean absolute error and mean absolute percentage error are used to evaluate the prediction results and analyze the prediction residual.The results show that under different conditions(ionosphere quiet period and active period),the prediction accuracy of the model is higher,which is better than the unimproved Prophet frame,significantly better than the autoregressive integrated moving average(ARIMA)model,and has good applicability in middle and high latitudes.