TY - JOUR
T1 - Overview of Akatsuki data products
T2 - definition of data levels, method and accuracy of geometric correction
AU - Ogohara, Kazunori
AU - Takagi, Masahiro
AU - Murakami, Shin ya
AU - Horinouchi, Takeshi
AU - Yamada, Manabu
AU - Kouyama, Toru
AU - Hashimoto, George L.
AU - Imamura, Takeshi
AU - Yamamoto, Yukio
AU - Kashimura, Hiroki
AU - Hirata, Naru
AU - Sato, Naoki
AU - Yamazaki, Atsushi
AU - Satoh, Takehiko
AU - Iwagami, Naomoto
AU - Taguchi, Makoto
AU - Watanabe, Shigeto
AU - Sato, Takao M.
AU - Ohtsuki, Shoko
AU - Fukuhara, Tetsuya
AU - Futaguchi, Masahiko
AU - Sakanoi, Takeshi
AU - Kameda, Shingo
AU - Sugiyama, Ko ichiro
AU - Ando, Hiroki
AU - Lee, Yeon Joo
AU - Nakamura, Masato
AU - Suzuki, Makoto
AU - Hirose, Chikako
AU - Ishii, Nobuaki
AU - Abe, Takumi
N1 - Funding Information:
The authors thank all the members of the Akatsuki project team for their remarkable support in developing and operating the spacecraft and process‑ ing data on the ground. This study is partially supported by JSPS KENHI 16H02231 and 16H02225.
Funding Information:
This study is partially supported by JSPS KAKENHI 16H02231 and 16H02225.
Publisher Copyright:
© 2017, The Author(s).
PY - 2017/12/1
Y1 - 2017/12/1
N2 - We provide an overview of data products from observations by the Japanese Venus Climate Orbiter, Akatsuki, and describe the definition and content of each data-processing level. Levels 1 and 2 consist of non-calibrated and calibrated radiance (or brightness temperature), respectively, as well as geometry information (e.g., illumination angles). Level 3 data are global-grid data in the regular longitude–latitude coordinate system, produced from the contents of Level 2. Non-negligible errors in navigational data and instrumental alignment can result in serious errors in the geometry calculations. Such errors cause mismapping of the data and lead to inconsistencies between radiances and illumination angles, along with errors in cloud-motion vectors. Thus, we carefully correct the boresight pointing of each camera by fitting an ellipse to the observed Venusian limb to provide improved longitude–latitude maps for Level 3 products, if possible. The accuracy of the pointing correction is also estimated statistically by simulating observed limb distributions. The results show that our algorithm successfully corrects instrumental pointing and will enable a variety of studies on the Venusian atmosphere using Akatsuki data.
AB - We provide an overview of data products from observations by the Japanese Venus Climate Orbiter, Akatsuki, and describe the definition and content of each data-processing level. Levels 1 and 2 consist of non-calibrated and calibrated radiance (or brightness temperature), respectively, as well as geometry information (e.g., illumination angles). Level 3 data are global-grid data in the regular longitude–latitude coordinate system, produced from the contents of Level 2. Non-negligible errors in navigational data and instrumental alignment can result in serious errors in the geometry calculations. Such errors cause mismapping of the data and lead to inconsistencies between radiances and illumination angles, along with errors in cloud-motion vectors. Thus, we carefully correct the boresight pointing of each camera by fitting an ellipse to the observed Venusian limb to provide improved longitude–latitude maps for Level 3 products, if possible. The accuracy of the pointing correction is also estimated statistically by simulating observed limb distributions. The results show that our algorithm successfully corrects instrumental pointing and will enable a variety of studies on the Venusian atmosphere using Akatsuki data.
KW - Data product
KW - Ellipse-fitting technique
KW - Pointing correction
KW - Venus
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U2 - 10.1186/s40623-017-0749-5
DO - 10.1186/s40623-017-0749-5
M3 - Article
AN - SCOPUS:85037721330
SN - 1880-5981
VL - 69
JO - Earth, Planets and Space
JF - Earth, Planets and Space
IS - 1
M1 - 167
ER -
