利用IMAGE卫星观测数据重建地球等离子体层的磁赤道面分布

Using IMAGE Data for Observe the Plasma Density Distribution of the Geomagnetic Equatorial Plane

美国利用IMAGE卫星的极紫外辐射(EUV)探测器对地球等离子体层进行了连续5年的遥感成像观测。由于IMAGE卫星数据是沿观测路径上的积分投影数据,并且存在地球"遮挡"、"阴影"、"数据缺失"等问题,无法直接利用传统的CT方法对等离子体层进行三维重建。本文利用地球磁场模型,基于地球等离子体层的物理性质,建立一个联系地球磁赤道面密度与投影数据的EUV成像模型,实现了从单个角度的EUV观测图像进行地球等离子层三维重构的方法。

The IMAGE satellite has been observed the Earth＇s plasmasphere for 5 years, it provides a large quantity of practicable data for the plasmaspheric research. However, IMAGE data had the three problems： ＇the earth shelter＇, ＇the sunlight shadow＇ and ＇the lack of data＇, so the traditional CT methods can not directly reconstruct the earth＇s plasmasphere. In this paper, by using the earth＇s magnetic field model and starting from the physical properties of the Earth＇s plasmasphere, we establish a new EUV imaging model which associates with the surface density of the Earth＇s magnetic equator and the projection data. Then we use an ART-type technique to inverse compute this model and acquire the density distribution of geomagnetic equatorial plane. This method realized a 3D plasmaspheric density distribution was computed from the single angle of the EUV observed images In addition, we evaluated the result by using the simulated data and the IMAGE data; it was show that the method is feasible and effective.