三亚地区电离层foF2的混沌特性分析及其预测研究

Analysis of chaotic features and prediction of ionospheric foF2 in Sanya

利用三亚台站2013年电离层foF2观测数据,讨论了电离层foF2的混沌特性及其预测.采用改进的C-C算法确定时间延迟和嵌入维数,计算最大李雅普诺夫指数,定量地印证foF2时间序列具有混沌特性.基于RBF神经网络的方法对foF2参量进行短期预报,并将预报结果与Volterra模型、IRI模型和实测数据进行对比.结果表明,采用RBF神经网络法可成功预测foF2的变化,相比于国际参考电离层模型有较大提高,较Volterra模型也有一定提升.在一定时间尺度内,RBF神经网络预测结果较为准确,预测误差较小,超出该预测范围,预测效果将变差.

Chaotic features of critical frequency of the ionospheric F2 layer(foF2)and its prediction are discussed based on the observation data of foF2 in Sanya in 2013.The improved C-C algorithm is adopted to determine the time delay and embedding dimension and the maximum Lyapunov index is calculated to verify the chaotic property of foF2 time series quantitatively.The method based on RBF neural network is used for short-term forecast of foF2 parameters and the forecast results were compared with the Volterra model,the IRI model and the measured ones.It shows that RBF neural network can predict the variation of foF2 successfully.The method of using RBF neural network is superior to IRI model and Volterra model.Predicted results are more accurate and less prediction errors within a certain time scale using RBF neural network.Beyond the range,the effect will be worse.