Methods to derive the magnetopause from soft X-ray images by the SMILE mission

Abstract

Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) is a novel self-standing mission dedicated to observing the solar wind–magnetosphere coupling via simultaneous in situ solar wind/magnetosheath plasma and magnetic field measurements, soft X-ray images of the magnetosheath and polar cusps, and UV images of global auroral distributions. While analyzing the observed images after the launch of SMILE, it will be a challenging task to reconstruct the 3-dimensional surface of the magnetopause from 2-dimensional images. Therefore, one of the most important key issues about SMILE is the reconstruction of magnetopause from X-ray images. This paper will review four main approaches have been developed so far, namely, the boundary fitting approach (BFA), the tangent fitting approach (TFA), the tangential direction approach (TDA), and the computed tomography approach (CTA). We will discuss their scope of application and pros and cons, and hopefully inspire future efforts.