角秒级精度、千赫兹更新率数字太阳敏感器实现方法研究

The Digital Sun Sensor (DSS) is one of the most important sensors for the attitude measurement of the satellites. With the advantages of the remote sensing and solar observation, a DSS with high accurate, large Field of View (FOV) and high data update rate is required; while such high performance DSS cannot be developed with current technologies and methods. Based on the Electronic Rolling Shutter (ERS) imaging mode of an APS CMOS detector, a new approach is proposed to improve the data update rate which was limited by the frame period of the image detector. Using ERS, the sun spots scattering in different lines of a frame will update every time the data of a line is readout and thus, the kHz level data update rate of the DSS could be achieved, which is two orders of magnitude better than that of the conventional DSS. Based on a multiplexing image detector method, a plane mask fabricated with MEMS procedures is employed to resolve the restriction between accuracy and FOV. The whole FOV is subdivided into several sub-FOVs by different patterns on the mask which could be distinguished from each other, and both a large FOV of 120°×120°and high accuracy could be achieved based on such method. Along with the system calibration method with respect to different error sources, the accuracy could be improved by one order of magnitude and arc-second level accuracy could be accomplished. The result of this research could enhance the function density of a DSS dramatically and lay the foundation for the application of DSS in the missions such as high-resolution earth observation images and solar observation.

数字太阳敏感器是卫星重要的姿态敏感器之一。随着遥感卫星技术、对日观测卫星技术的发展，数字太阳敏感器面临大视场、高精度、高更新率的需求，而现有技术无法实现高性能数字太阳敏感器的研制。为了突破传统数字太阳敏感器的数据更新率受帧周期的限制，本项目利用APS电子卷帘曝光模式，以图像探测器的行图像为单位，实现单帧图像中不同位置光斑的动态更新，将数据更新率提升2个量级，达到1kHz水平。为了解决目前数字太阳敏感器视场角和精度矛盾的问题，本项目提出了基于MEMS平面光线引入器的图像探测器复用方法，利用多组互相可区分的图案实现系统视场角的细分，突破了视场角对测量精度的限制，在保持120°×120°视场角的情况下，结合内外参数分离的高精度测量和标定方法，将测量精度提升了1个量级，达到角秒级水平。本项目的研究成果将显著提升数字太阳敏感器的功能密度，为数字太阳敏感器在高分辨率成像、对日观测等方向的应用奠定基础。

数字太阳敏感器是卫星重要的姿态敏感器之一。随着遥感卫星技术、对日观测卫星技术的发展，数字太阳敏感器面临大视场、高精度、高更新率的需求，而现有技术无法实现高性能数字太阳敏感器的研制。为了突破传统数字太阳敏感器的数据更新率受帧周期的限制，本项目提出提出了数字太阳敏感器姿态行周期技术，基于CMOS图像探测器的卷帘成像方式，实现单帧图像中不同位置光斑的动态更新，将数据更新率提升2个量级，达到1kHz水平。为了解决目前数字太阳敏感器视场角和精度矛盾的问题，本项目提出了基于MEMS平面光线引入器的图像探测器复用方法，利用多组互相可区分的图案实现系统视场角的细分，并且建立了太阳光斑的衍射成像模型，针对各个分视场进行光线引入器图案尺寸优化，在保持120°×120 °视场角的情况下，结合内外参数分离的高精度测量和标定方法，将本项目研制的高性能数字太阳敏感器样机的测量精度提升了1个量级，达到角秒级水平。本项目的研究成果将显著提升数字太阳敏感器的功能密度，从根本上突破了限制数字太阳敏感器性能提升的关键技术，为数字太阳敏感器在高分辨率成像、对日观测等方向的应用奠定基础。