Abstract Soft X‐rays are emitted in the magnetosheath and cusps because of solar wind charge exchange. The soft X‐ray Imager (SXI) on board Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) will measure these X‐rays. We developed a new method for finding the magnetopause standoff distance from simulations that reproduce the expected X‐ray images using software developed by the SXI instrument team. We consider three points near the SMILE apogee. We apply this method to a three‐hour interval with an interplanetary shock and a southward interplanetary magnetic field turning when the magnetosphere was moderately compressed. The results show that the magnetopause position can be reconstructed with an accuracy better than 0.5 for a five‐minute integration time, which matches the SMILE scientific requirements. Moreover, we can even determine the magnetopause position using one‐minute integration when the magnetosphere is strongly compressed and the spacecraft's position and SXI's orientation are favorable for magnetopause observations.
Samsonov et al. (Sun,) studied this question.