A new inversion method for reconstruction of plasmaspheric He+ density from EUV images

The Computer Tomography (CT) method is used for remote sensing the Earth's plasmasphere. One challenge for image reconstruction is insufficient projection data, mainly caused by limited projection angles. In this study, we apply the Algebraic Reconstruction Technique (ART) and the minimization of the image Total Variation (TV) method, with a combination of priori knowledge of north‐south symmetry, to reconstruct plasmaspheric He+ density from simulated EUV images. The results demonstrate that incorporating priori assumption can be particularly useful when the projection data is insufficient. This method has good performance even with a projection angle of less than 150 degrees. The method of our study is expected to have applications in the Soft X‐ray Imager (SXI) reconstruction for the Solar wind‐Magnetosphere‐Ionosphere Link Explorer (SMILE) mission. Key Points Present a new method to reconstruct the plasmaspheric He+ global density distribution from two dimensional Extreme Ultraviolet images. The new method has superior performance with insufficient projection data. The method can be generalized to study soft X‐ray images from the Solar wind‐Magnetosphere‐Ionosphere Link Explorer mission.