摘要
平静状态下电离层总电子含量(TEC)随时间的变化通常可以视为平稳随机过程。然而，太阳或地球的突发事件(如太阳耀斑、地磁场的扰动)会引起电离层的扰动，破坏该平稳过程，从而引起其统计参数的变化。依据平稳随机过程—高斯过程的相关性质，利用其自协方差函数和TEC时间系列，构建了独立同标准正态分布的观测样本，并利用x^2假设检验的方法来探测电离层异常现象。此外，还利用了2000年7月14日太阳耀斑期间我国国际IGS跟踪站武汉GPS跟踪站的数据，进行了实例分析。结果表明，该方法可以有效地探测电离层异常现象。
Usually, ionospheric Total Electron Conten （TEC） variation with time can be viewed as a stationary random process under quiet conditions. However, sudden events of the Sun and the Earth such as solar flare and sudden commencement of geomagnetic storms may induce the disturbances of the ionosphere, so that the stationary random process is broken which will lead to the statistical model parameters changing. Based on this fact, here we made use of the time series of TEC and the auto-covariance function of the stationary process to construct independent identical distribution Gauss sample so that the X^2 test can be used to detect the abnormity hidden in the sequence. In addition, GPS data collected by several IGS sites over China during the severe solar flare occurred on July 14, 2000 are used to verify the method. The results indicate that the disturbances caused by the solar flare can be effectively detected.
出处
《天文学进展》
CSCD
北大核心
2005年第4期363-370,共8页
Progress In Astronomy
