Automated cloud tracking system for the Akatsuki Venus Climate Orbiter data |
| |
| Authors: | Kazunori Ogohara Toru Kouyama Hiroki Yamamoto Naoki Sato Masahiro Takagi Takeshi Imamura |
| |
| Institution: | 1. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa, Japan;2. Department of Earth and Planetary Science, University of Tokyo, 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa, Japan;3. Department of Earth and Planetary Science, Kyoto University, Oiwake, Kitashirakawa, Sakyo, Kyoto, Japan;4. Natural Science Division, Tokyo Gakugei University, 4-1-1 Nukuikita-machi, Koganei, Tokyo, Japan;5. Department of Earth and Planetary Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan;1. Cornell University, Dept of Astronomy, 318 Space Sciences Building, Ithaca, NY, 14853, USA;2. Observatoire de Paris, LESIA, 5 Place Jules Janssen, 92195 Meudon Cedex, France;3. University of Wisconsin-Madison, Space Science and Engineering Center, 1225 West Dayton Street, Madison, WI 53706, USA;4. Jet Propulsion Laboratory, M/S 183-501, 4800 Oak Grove Drive, Pasadena, CA 91109 USA |
| |
| Abstract: | Japanese Venus Climate Orbiter, Akatsuki, is cruising to approach to Venus again although its first Venus orbital insertion (VOI) has been failed. At present, we focus on the next opportunity of VOI and the following scientific observations.We have constructed an automated cloud tracking system for processing data obtained by Akatsuki in the present study. In this system, correction of the pointing of the satellite is essentially important for improving accuracy of the cloud motion vectors derived using the cloud tracking. Attitude errors of the satellite are reduced by fitting an ellipse to limb of an imaged Venus disk. Next, longitude–latitude distributions of brightness (cloud patterns) are calculated to make it easy to derive the cloud motion vectors. The grid points are distributed at regular intervals in the longitude–latitude coordinate. After applying the solar zenith correction and a highpass filter to the derived longitude–latitude distributions of brightness, the cloud features are tracked using pairs of images. As a result, we obtain cloud motion vectors on longitude–latitude grid points equally spaced. These entire processes are pipelined and automated, and are applied to all data obtained by combinations of cameras and filters onboard Akatsuki. It is shown by several tests that the cloud motion vectors are determined with a sufficient accuracy. We expect that longitude–latitude data sets created by the automated cloud tracking system will contribute to the Venus meteorology. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
