代数重建法反演环电流分布的初步结果

New Results of Algebraic Reconstruction Techniques to Inverse Ring Current Ions Distribution

TC-2卫星携带了高能中性原子成像仪．在理论上可以根据对中性原子的探测通过反演获得磁层中环电流的空间分布．开发了一种新的反演技术和算法来反演环电流的分布．文中将层析成像技术引入反演环电流区离子分布,把磁层空间环电流区域划分为网格并依据层析成像常用的代数重建法反演环电流的分布．反演前后的环电流离子分布具有一致性,证实了这种反演方法的可行性．通过对比反演结果与初始分布,模型通过较少的假设和简单的步骤就可以获得全面的环电流信息．

Energetic Neutral Atom （ENA） images obtained by the energetic Neutral Atom Detector Unit （NUADU） on board Chinese Double Star mission are used to simulate the changes in the ring current. Changes in the ring current are responsible for global decreases in the Earth surface magnetic field, which are known as geomagnetic storms. ENA imagers provide global pictures of the ring current ions in the space environment. A new technique and arithmetic is explored in this paper to inverse the ring current ions distribution. The technique of seismic tomograpy is introduced into our inversion. Based on the technique, the ring current region of magnetospheric space can be took into grids and use Algebraic Reconstruction Techniques to extract ion＇s flux distribution from the ENA image. The consistency inversion distribution with original one shows the feasibility of this technique. Comparing the original distribution with the inversion results, our arithmetic can obtain ring currents＇ global distribution information with fewer hypotheses and simpler procedures.