Ryuhei Yamada
A5028128700- Planetary Science and Exploration
- Astro and Planetary Science
- Space Exploration and Technology
- Geophysics and Gravity Measurements
- Spacecraft and Cryogenic Technologies
- Space Satellite Systems and Control
- Robotics and Sensor-Based Localization
- Astronomical Observations and Instrumentation
- Space Science and Extraterrestrial Life
- 3D Surveying and Cultural Heritage
- Advanced Optical Sensing Technologies
- Inertial Sensor and Navigation
- Geophysics and Sensor Technology
- Seismology and Earthquake Studies
- Remote Sensing and LiDAR Applications
- Earthquake Detection and Analysis
- Robotics and Automated Systems
- Ionosphere and magnetosphere dynamics
- Geology and Paleoclimatology Research
- Satellite Image Processing and Photogrammetry
- Gamma-ray bursts and supernovae
- Isotope Analysis in Ecology
- GNSS positioning and interference
- Atmospheric and Environmental Gas Dynamics
- earthquake and tectonic studies
National Astronomical Observatory of Japan
2013-2025
Osaka University
2025
Osaka Prefectural Medical Center
2016-2025
University of Aizu
2017-2024
Bunkyo University
2023
Institut für Lungenforschung
2022
Planet
2022
Osaka City General Hospital
2016-2021
Japan Aerospace Exploration Agency
2008-2015
Astronomical Observatory
2014
Hayabusa2 at the asteroid Ryugu Asteroids fall to Earth in form of meteorites, but these provide little information about their origins. The Japanese mission is designed collect samples directly from surface an and return them for laboratory analysis. Three papers this issue describe team's study near-Earth carbonaceous 162173 Ryugu, which spacecraft arrived June 2018 (see Perspective by Wurm). Watanabe et al. measured asteroid's mass, shape, density, showing that it a “rubble pile” loose...
Abstract The internal structure of the Moon is important for discussions on its origin and evolution. However, deep still debated due to absence comprehensive seismic data. This study explores lunar interior models by complementing Apollo travel time data with selenodetic which have recently been improved Gravity Recovery Interior Laboratory (GRAIL) Lunar Laser Ranging (LLR). observed can be explained including a deep‐seated zone low velocity ( S wave = 2.9 ± 0.5 km/s) viscosity (∼3 × 10 16...
Salivary duct carcinoma (SDC) originating from the minor salivary glands is extremely rare. We report a case of SDC arising gland tissue at tip tongue. A 67-year-old man presented with complaint mass and pain in Magnetic resonance imaging showed high-signal area isolated anterior lingual Since fine-needle-aspiration-cytology failed to diagnose benign or malignant tumor, diagnosis suspected was made by intraoperative rapid diagnosis, tumor resected. The histopathological SDC. high-grade that...
Abstract The Lunar Geophysical Network (LGN) mission is proposed to land on the Moon in 2030 and deploy packages at four locations enable geophysical measurements for 6–10 yr. Returning lunar surface with a long-lived network key next step advance planetary science. LGN will greatly expand our primarily Apollo-based knowledge of deep interior by identifying characterizing mantle melt layers, as well core size state. To meet objectives, instrument suite provides complementary seismic,...
A new technology consisting of a distributed temperature array system has been deployed for the first-time during exploration drillstem testing (DST). It was successfully used to evaluate fluid movements across and into tested formation throughout operations helped characterize vertical heterogeneities in complex carbonate reservoir without in-well intervention. The acquire profile data entire sequence drill-stem operations, from run hole through perforation, stimulation, flow, fluids...
Abstract The precise orbit of the Hayabusa2 spacecraft with respect to asteroid Ryugu is dynamically determined using data sets collected by spacecraft’s onboard laser altimeter (LIght Detection And Ranging, LIDAR) and automated image tracking (AIT). LIDAR range AIT angular play complementary roles because sensitive line-of-sight direction from Ryugu, while directions perpendicular it. Using AIT, all six components initial state vector can be derived stably, which difficult achieve only or...
Lunar impact flashes have been observed at collisions of meteoroids against the non-sunlit lunar surface speeds exceeding 10 km s−1. We detected 13 flash candidates between 6.2 and 9.9 in R-magnitude on December 15, 2018 during Geminids meteor activity. Two or three observatories confirmed eleven them. obtained their spectra wavelength range 400 870 nm. They are continuous red, with best-fitted single blackbody indicating temperatures about 2000–4000 K. The for a few successive movie...
Whitepaper #098 submitted to the Planetary Science and Astrobiology Decadal Survey 2023-2032. Topics: interior evolution volcanism; Mercury and/or Moon; solar system formation, dynamics processes, chronology
Abstract In this study, we determined the alignment of laser altimeter aboard Hayabusa2 with respect to spacecraft using in-flight data. Since data were used estimate trajectory spacecraft, pointing direction needed be accurately determined. The boresight receiving telescope was estimated by comparing elevations and camera images, confirmed identifying prominent terrains other datasets. obtained link experiment in winter 2015, during Earth’s gravity assist operation period, differed from...