SLIMプロジェクトチーム

Ryodo Hemmi

  (逸見 良道)

Profile Information

Affiliation
Researcher, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency

ORCID ID
 https://orcid.org/0000-0002-9638-6926
J-GLOBAL ID
201701019513699984
Researcher ID
AAU-1566-2020
researchmap Member ID
B000274755

Papers

 27
  • Lisa M. Vincent, Trishit Ruj, Goro Komatsu, Aditya Ray, Hiroshi Kikuchi, Ryodo Hemmi, Hideaki Miyamoto, Seiji Sugita
    Journal of Geophysical Research: Planets, Jul, 2026  
  • Hemmi, Ryodo, Inoue, Hiroka, Kikuchi, Hiroshi, Sato, Hiroyuki
    The Planetary Science Journal, Nov 14, 2025  
    <jats:title>Abstract</jats:title> <jats:p> High-quality digital terrain models (DTMs) are essential for lunar polar missions, aiding mission planning and surface operations. The horizontal resolution and vertical accuracy of DTMs are generally limited by factors such as source image resolution, image noise, the precision of ground control points (GCPs), and data processing techniques. In this study, we produced advanced DTMs for the lunar south pole region by integrating seamless mosaics generated from multiple Lunar Reconnaissance Orbiter Camera Narrow Angle Camera image pairs captured under various illumination azimuths. To enhance accuracy and reduce artifacts, we employed bundle adjustment with hundreds of meticulously selected image-to-image tie points and precise GCPs, combined with an advanced multiview shape-from-shading technique. This technique, which utilizes multiple viewpoints to resolve topographic details with higher precision, significantly improves vertical accuracy and resolution. Our methodology achieves a spatial resolution of 1 m pixel <jats:sup>−1</jats:sup> and vertical precision of ±1.0 m, enabling clearer delineation of meter-scale lunar topographic features compared to previous models. These DTMs are expected to significantly support the Lunar Polar Exploration project and other forthcoming lunar exploration missions. </jats:p>
  • Hemmi, Ryodo, Kikuchi, Hiroshi
    Remote Sensing, Sep 21, 2025  
    <jats:p>We present an automated and fully reproducible pipeline for restoring motion-smeared Mars Express SRC images of Phobos. A one-dimensional motion point spread function (PSF) is derived directly from SPICE geometry and microsecond-precision exposure timing, and Wiener deconvolution (SNR = 16 dB) is applied to recover image sharpness. Tested on 14 images from 4 orbits spanning slant distances of 52–292 km, exposures of 14–20 milliseconds, sampling of 0.47–2.7 m/pixel, and PSF lengths of 11–119 pixels, the method achieves up to 31.7 dB PSNR, 0.78 SSIM, and positive sharpness gains across all cases. The restored images reveal sub-meter surface features previously obscured by motion blur, with residual energy reduced relative to the acquisition model. The workflow relies solely on open data and open-source tools (ISIS, ALE/SpiceyPy, OpenCV), requires no star-field calibration, and generalizes to other motion-degraded planetary datasets, providing a fully transparent and reproducible solution for high-resolution planetary imaging.</jats:p>
  • Sofia McLeod, Chee Kheng Chng, Tatsuharu Ono, Yuta Shimizu, Ryodo Hemmi, Lachlan Holden, Matthew Rodda, Feras Dayoub, Hirdy Miyamoto, Yukihiro Takahashi, Yasuko Kasai, Tat-Jun Chin
    2024 IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshops (CVPRW), 6760-6769, Jun 17, 2024  

Misc.

 7

Research Projects

 2