2020/05/01 by Kyuhyoun Cho, Jongchul Chae, Ryun-Young Kwon +4
Physics and Astronomy · #Algorithm #Astro and Planetary Science #Astrophysics #Computer science #Computer vision #Corona (planetary geology) #Coronagraph #Coronal plane #Extreme ultraviolet #Extreme ultraviolet lithography #Iterative reconstruction #Optics #Physics #Solar and Space Plasma Dynamics #Stellar, planetary, and galactic studies #Tomography #astro-ph.SR
paper · pdf · doi:10.3847/1538-4357/ab88af
Accepted for ApJ
openalex publication_date 2020/05/01 · arxiv created 2020/05/20 · openalex created_date 2020/05/29 · arxiv updated 2020/06/03 · openalex updated_date 2026/08/05
Abstract Solar rotational tomography (SRT) is an important method to reconstruct the physical parameters of the three-dimensional solar corona. Here we propose an approach to apply the filtered backprojection (FBP) algorithm to the SRT. The FBP algorithm is generally not suitable for SRT due to the several issues with solar extreme ultraviolet (EUV) observations—in particular, a problem caused by missing data because of the unobserved back side of corona hidden behind the Sun. We developed a method to generate a modified sinogram that resolves the blocking problem. The modified sinogram is generated by combining the EUV data at two opposite sites observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory (SDO). We generated the modified sinogram for about one month in 2019 February and reconstructed the three-dimensional corona under the static state assumption. In order to obtain the physical parameters of the corona, we employed a differential emission measure inversion method. We tested the performance of the FBP algorithm with the modified sinogram by comparing the reconstructed data with the observed EUV image, electron density models, previous studies of electron temperature, and an observed coronagraph image. The results illustrate that the FBP algorithm reasonably reconstructs the bright regions and the coronal holes and can reproduce their physical parameters. The main advantage of the FBP algorithm is that it is easy to understand and computationally efficient. Thus, it enables us to easily probe the inhomogeneous coronal electron density and temperature distribution of the solar corona.