Development of infrared imaging devices for the observation of planetary atmosphere

开发用于观测行星大气的红外成像装置

• 批准号: 13440142
• 负责人: NAKAMURA Masato
• 金额: $ 9.6万
• 依托单位: Institute of Space and Astronautical Science (2002)The University of Tokyo (2001)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13440142/
• 关键词: Venus Atmosphere; Infrared detector; 金星; 気象; イメージング; 赤外線; ショットキーバリヤ

The motion of the atmosphere of Venus at the altitude of less than 70km has not been studied because it is prevented by the thick cloud layer. But it became possible to observe the motion of lower clouds and surface of Venus after infrared ray turned out to pass through the thick cloud layer. We aimed at the observation of the motion of the atmosphere using Venusian clouds and surface as tracers by the infrared camera in the spacecraft orbiting around Venus. This approach will be the first one in the world.In this study, we developed the imaging device and optical system for infrared camera which can be used in the exploration of Venus and also future exploration of another planet. It is especially important to develop the imaging device and optical system in two bands, near-infrared region (1-3μm) and mid-infrared region (8-12μm). The former corresponds to the emission from the bottom of clouds (at the altitude of 50-70km), which enables us to observe the motion of the atmosphere. On the contrary, the latter corresponds to the thermal radiation from the top of clouds. As a result, it turned out to be best to use PtSi Schottky device in near infrared region and bolometer array in mid-infrared region as radioresistant imaging device. Schottky device needs to be cooled to 60K, and one stage Stirling cooler proved to be able to accomplish it.This research is relatively close to the development of infrared observation spacecraft in astronomical field. In this field, the technology which reduces a thermal noise to the minimum by cooling the infrared device has been improved for the observation of far, dark stars or young planetary system. But, if it is installed to planetary exploration spacecraft, it will be prolonged exposure to the radiation and also the much harsher heat condition than ground-based astronomical observations. In this time, the development of the infrared device suitable for the planetary orbiter was needed, and it was sufficiently achieved.

金星大气层在低于70公里高度的运动还没有被研究过，因为它被厚厚的云层所阻止。但是，当红外线穿透厚厚的云层后，就有可能观察到低云层和金星表面的运动。我们的目标是利用环绕金星的航天器上的红外相机，以金星云和金星表面为示踪物，观测大气层的运动。本研究开发了红外相机的成像装置和光学系统，可用于金星探测，也可用于未来的其他行星探测。因此，研制近红外（1-3μm）和中红外（8-12μm）两个波段的成像器件和光学系统尤为重要。前者对应于来自云底（海拔50- 70公里）的发射，使我们能够观察大气的运动。相反，后者对应于来自云顶的热辐射。结果表明，在近红外波段采用PtSi肖特基器件，在中红外波段采用测辐射热计阵列作为抗辐射成像器件是最好的。肖特基器件需要冷却到60 K，一级斯特林冷却器被证明能够完成，这项研究与天文领域红外观测航天器的发展比较接近。在该领域中，通过冷却红外装置将热噪声降低到最小的技术已经得到改进，用于观测遥远的暗恒星或年轻的行星系统。但是，如果它被安装到行星探测航天器上，它将长时间暴露在辐射中，并且比地面天文观测更苛刻的热条件。在这段时间里，需要开发适合行星轨道器的红外装置，并且已经充分实现。

项目成果

M. Nakamura, and T. Imamura: "Japanese Venus atmospheric mission"Yuseijin. 10(3). (2001)

M. Nakamura 和 T. Imamura：“日本金星大气任务”Yuseijin。

T. Imamura, and G. L Hashimoto: "Microphysics of Venusian clouds in rising tropical air."J. Atmos. Sci. 58. 3597-3612 (2001)

T. Imamura 和 G. L Hashimoto：“热带空气上升中金星云的微观物理学”。

松田佳久, 今村剛: "金星大気の謎にせまる日本の金星探査計画"科学. 71(9). 1162-1164 (2001)

Yoshihisa Matsuda，Tsuyoshi Imamura：“日本的金星探索计划接近金星大气层的奥秘”，《科学》71(9) 1162-1164 (2001)。

Y. Matsuda, and T. Imamura: "Revealing the mystery of Venusian atmosphere by Japanese Venus mission"Kagaku. 71(9). (2001)

Y. Matsuda 和 T. Imamura：“日本金星任务揭示金星大气层之谜” Kagaku。

T.Imamura, G.L.Hashimoto: "H2SO4 cycle in the Venusian tropical atmosphere as constrained by a microphysical cloud model"Adv.Snpace.Res. 29(2). 249-254 (2002)

T.Imamura、G.L.Hashimoto：“受微物理云模型约束的金星热带大气中的 H2SO4 循环”Adv.Snpace.Res。