基于帧转移CCD的超高动态循环曝光控制技术研究

Ultra-high Dynamic Cyclic Exposure Control Technique Based on Frame Transfer CCD

摘要:

提出了一种可大幅度提升高光谱成像探测动态范围的基于帧转移电荷耦合器件(CCD)的曝光控制技术。该技术采用先积分后读出的工作模式,结合CCD快速电荷倾倒时序控制方法,能够有效清除空闲时段的无效电荷,实现超短积分时间和长积分时间曝光周期的快速切换；针对同一被探测目标,在规定时间范围内通过多档积分周期之间的快速切换,实现多档曝光周期的不间断循环曝光,从而使该技术的光谱探测动态范围相较传统技术提升2个数量级以上。设计了循环曝光档数和曝光时间可动态设置方式,时序仿真与测试结果表明,该方式能够有效提升高光谱成像技术在复杂光环境下的适应性。

Abstract:

An exposure control technique based on frame transfer CCD is proposed to greatly improve the dynamic range in hyperspectral image detection. It adopts a new working mode of integrating first and then reading out, combined with the fast charge dumping timing control method of charge-coupled devices (CCD), which can effectively remove the invalid charge in the idle period and realize fast switching between the ultra-short integration time and the long integration time exposure period. For the same detected target, the uninterruptable cycle exposure of multiple exposure cycles can be realized by fast switching between multiple integral cycles within a specified time range, so that the spectrum detection range index of this technique can be improved by more than 2 orders of magnitude compared with that of the traditional technology. At the same time, the dynamic setting mode of cyclic exposure file number and exposure time is designed. The timing simulation analysis and test verifies that the proposed design can effectively improves the adaptability of hyperspectral imaging technology in complex light environment.