The sunspot sketches obtained at Tokyo Astronomical Observatory and National Astronomical Observatory by using a Zeiss 20cm refractor were digitized, and the coordinates of sunspots were collected in files "mtk_spotpos_<year>.txt".

List of entries:
NO = Mitaka sunspot number
YEAR, MO, DA = year, month (1-12), day of observation
HO, MI = observing time (hour and minute) in JST (=UT+9)
T = Zurich sunspot type (0=A, 1=AA, 2=B, 3=C, 4=D, 5=E, 6=F, 7=G, 8=H, 9=J)
    AA means non-single A-type spots
P = measured position in a group: 1(preceding), 2(following), 3(center)
LAT, LON, CLON = heliographic latitude, longitude, and Carrington longitude

The data up to 1992 April were compiled by Maspul Aini Kambry as part of his PhD thesis work at The University of Tokyo. The results are found in
     Kambry and Nishikawa, Solar Phys., 126, 89, 1990,
     Kambry et al., Solar Phys., 132, 41, 1991,
     Yoshimura and Kambry, Solar Phys., 143, 205, 1993.
His spot position digitization was to study the rotation period of sunspots, so that only groups within 70 deg from the central meridian and observed for two or more consecutive days were recorded.
The data from 1992 May to 1998 December were digitized by Yoko Ohtani, Takaya Sato, Seiichi Takahashi, Yuriko Yamazaki, Masaoki Hagino, Kyoichiro Aoki, Wakako Yoneshima (all from Meisei University) and Yohei Yamauchi (Graduate University for Advanced Studies/NAOJ). The positions of all sunspot groups were recorded during this period.