基于经验模态分解的地球同步轨道高能电子通量预报

Prediction of High-energy Electron Flux of Geosynchronous Orbit Based on Empirical Mode Decomposition

在磁暴恢复相期间,大量相对论(高能)电子从磁层的外辐射带渗透到地球同步轨道区.其中> 2 MeV的高能电子能够穿透卫星表面并聚积在材料内部,导致卫星无法正常运行或完全损坏.磁暴期间的高能电子通量变化的非平稳与非线性特征十分明显.通过实验发现,经验模态分解法能够极大地降低高能电子通量非平稳性问题造成的预报影响.以2008-2009年的数据作为训练集,2010-2013年数据作为测试集.结果表明:2010-2013年的预报率约为0.84;在太阳活动较为复杂的2013年,预报率达到0.81.引入经验模态分解后预报效率得到显著提高.

During the recovery of a magnetic storm,the relativistic electrons with MeV energy diffuse from the outer radiation belt to geosynchronous orbit. The electrons which energy are larger than 2 MeV could penetrate the surface of satellites and accumulate inside them. Such an electron flux effect could cause satellites to be unable to function properly or to fail completely. Relativistic electrons change very rapidly during the magnetic storm and are very non-stationary. These effects are reduced by empirical mode decomposition method. Data in 2008-2009 are used as the training set, and data in 2010-2013 are used as the testing set. The result shows that the average prediction efficiency of the testing set is 0.81. The solar activity is complex in 2013, and the prediction efficiency is up to 0.81. The prediction efficiency of electron flux has been greatly improved by using empirical decomposition method.