A paper led by Keiko Yamamoto of National Astronomical Observatory is published on Earth, Planets and Space.  The orbits of Hayabusa2 spacecraft and the GM of Ryugu are investigated.  Otsubo is involved in the key part of orbit analysis. 

K. Yamamoto, T. Otsubo, et al., Dynamic precise orbit determination of Hayabusa2 using laser altimeter (LIDAR) and image tracking data sets, Earth, Planets and Space, 72:85, https://doi.org/10.1186/s40623-020-01213-2, 2020.