天问一号多光谱相机设计与在轨验证

Design and on-orbit verification of Tianwen-1 multispectral camera

中国的首次火星探测任务天问一号探测器于2020年7月23日成功发射.多光谱相机是天问一号的重要载荷,安装在祝融号巡视器的桅杆上,其科学目标为获取着陆区及巡视区多光谱图像,研究火星表面物质组成,获取火星化学演化的基础信息.本文介绍了天问一号多光谱相机的方案及设计结果.基于提高可靠性考虑,天问一号多光谱相机通过切换8个不同厚度玻璃制成的窄带滤光片,实现多光谱成像并校正轴向色差;通过切换6个不同厚度的调焦补偿片来实现调焦功能.在轨工作科学数据表明多光谱相机图像清晰,光谱数据正常.

China’s first Mars exploration mission Tianwen-1 was successfully launched on July 23, 2020. The multispectral camera is an essential payload of Tianwen-1 and is installed on the mast of the Zhurong rover. The scientific goals of the mission are to obtain multispectral images of the landing and inspection zones, investigate the surface material composition on Mars, and obtain basic information on the chemical evolution of Mars. This article introduces the scheme and design results of the Tianwen-1 multispectral camera. To improve reliability, Tianwen-1 realizes multispectral imaging and corrects axial chromatic aberration by switching eight narrow-band filters with different thicknesses, and achieves focusing function by switching six focus compensation lenses of different thicknesses. The scientific data of on-orbit work shows that the image is clear and the spectral data are normal. The spectral reflectance data of the calibration board taken by the multispectral camera on Mars are consistent with the ground measurement data. The spectral reflectance data of the Martian surface obtained by the multispectral camera are basically consistent with the spectral reflectance data obtained by the Mars Reconnaissance Orbiter Imaging Spectrometer(CRISM) in orbit.