光学 精密工程, 2018, 26 (12): 3019, 网络出版: 2019-01-27
高灵敏度EMCCD导航相机的设计
Design of high-sensitivity EMCCD navigation camera
深空探测 导航相机 电子倍增电荷耦合器件 高动态 小天体 deep-space exploration navigation camera Electron-Multiplying Charge-coupled Device(EMCCD) high dynamic small celestial bodies
摘要
导航相机是深空探测领域中关键的导航敏感部件, 本文通过提高导航相机的灵敏度来提高导航相机的综合性能, 特别是提高时间分辨率, 解决高动态条件下的目标探测问题。首先, 根据导航相机的工作模式和EMCCD的性能特点, 分析了影响导航相机成像质量的多个因素, 建立了目标信噪比理论分析模型; 然后, 在理论计算基础上, 重点研究EMCCD导航相机的样机设计技术, 说明了EMCCD高频高幅驱动、模拟前端设计、TEC真空制冷、时序控制与数据处理等关键技术的实现方法; 最后, 介绍了相关实验工作, 并分析实验数据。实验结果表明: 样机最大目标信噪比在倍增增益M=10时达到68.6 dB, 在口径13 mm条件下, 可在积分时间1 ms内实现对月球成像。基本满足深空探测导航相机高动态条件下短积分时间成像的要求。
Abstract
The navigation camera is a sensitive component that is crucial for deep space exploration. This report describes a method for the comprehensive improvement of the performance of such a camera by increasing their sensitivity. In particular, the approach improves the temporal resolution of this instrument and simultaneously solves the target detection problem under high dynamic conditions. Firstly, the imaging quality of a navigation camera is analyzed according to the operating mode and the performance characteristics of an Electron Multiplying Charge-Coupled Device (EMCCD). In addition, a theoretical model of a target's signal-to-noise ratio (SNR) is established. Secondly, the study focused on the design method for an EMCCD navigation camera. Key technologies are illustrated such as the high-frequency high-amplitude drive circuit of an EMCCD, analog front circuitry, TEC vacuum cooling, timing control, and data processing. Finally, the experimental results show that the optimal target SNR is 68.6 dB at M = 10 and that the moon can be imaged using an integration time of 1 ms with a 13 mm aperture. The navigation camera satisfies the requirements of short integration time imaging under the high dynamic conditions associated with deep space exploration.
何家维, 何昕, 魏仲慧, 穆治亚, 李方彪. 高灵敏度EMCCD导航相机的设计[J]. 光学 精密工程, 2018, 26(12): 3019. HE Jia-wei, HE Xin, WEI Zhong-hui, MU Zhi-ya, LI Fang-biao. Design of high-sensitivity EMCCD navigation camera[J]. Optics and Precision Engineering, 2018, 26(12): 3019.