A Prediction Model For Energetic Electrons At GEO Orbit Based On Empirical Orthogonal Function

Energetic electrons flux in the radiation belt will sharply increase in the duration of storm magnetic storm, which is called relativistic electrons enhancement event. The energetic electrons have the extremely strong penetrating power, and seriously endanger the safety of the spacecraft. The Earth synchronous orbit is located at the 6.6Re geocentric distance from the Earth, which operates hundreds of application satellites. While the region is also the outer edge of the outer radiation belt, which is full of the electrons with energy up to Me V. Therefore, the establishment of a reliable synchronous orbit electrons flux model to predict the energetic electron event will enable us to take effective measures in advance to reduce the harm caused by energetic electrons to the spacecraft.The high time resolution electrons flux model can timely and effectively warn energetic electrons events, but the previous prediction models are mainly for daily average flux of energetic electrons, and electrons flux model with 5-minute resolution is rarely discussed. In this thesis, we propose a model based on empirical orthogonal function(EOF) method for the prediction of the energetic electrons flux of the earth synchronous orbit. The model firstly analyzes the 5min mean electrons flux data with energy larger than 2Me V, and extracts the EOF function which characterizes the property of the time change of electrons flux. Then the EOF coefficients for tomorrow's electrons flux are fitted by the solar wind parameters and geomagnetic indices. At last, the tomorrow's electrons mean flux forecast with 5minute resolution is given based on the EOF basis function.The test results for the data from January 2003 to June 2006 show that the model can reconstruct the real changes of the electrons flux and the fluctuation of energetic electrons flux during the enhancement event. The model can give electrons 5min mean flux prediction with 67% forecast efficiency during all universal time. Consequently the model based on the empirical orthogonal function method can be used to predict the electron flux with high time resolution.