[P-PS03] Small Bodies in the Solar System: Current Understanding and Future Prospects

[PPS03-P13] Shape model reconstruction of Ryugoid using Stereophotoclinometry

*Sayuri Tanaka¹, Naoyuki Hirata¹, Naru Hirata², Naoki Nishikawa¹, Sei-ichiro WATANABE³, Yoshiaki Ishihara⁴, Satoshi Tanaka⁴, Tomohiro Yamaguchi⁴, Akira Miura⁴, Yukio Yamamoto⁴ (1.Kobe University, 2.ARC-Space, the University of Aizu, 3.Nagoya University, 4.ISAS/JAXA)

Keywords:Hayabusa2, Ryugu, shape model reconstruction

The asteroid exploration mission, Hayabusa2, needs to develop the shape model of 162173 RYUGU, because the shape model helps to control the spacecraft safely and examine the nature of the asteroid. We utilized images of a vertical asteroid Ryugoid generated for a dry-run test of LSS sequence to simulate the real RYUGU, developed its image-based shape model, and evaluated its accuracy from comparing it with the true shape of Ryugoid. Then, we use software called Gaskell’s Stereophotoclinometry (SPC), which develops the shape using stereo imaging and photoclinometry. The former method determines the elevation from the parallax between two or more images. The latter method determines the slope and albedo from the variation in brightness of three or more images. We used a sphere with 450 m in radius as an initial shape and 128 boxA images with a resolution of ~ 2.0 m/pixel, 101 boxC images (0.5-0.7 m/pixel), 220 Mid-Altitude images (~0.5 m/pixel), and additional images to show the southern hemisphere. As a result, we made the shape model of entire Ryugoid. In the presentation, we will show our shape model, its accuracy compared with the true shape, and the time required to develop it.