机械快门对大面阵滤光片型多光谱相机成像的影响及改进

摘要

分析了大面阵滤光片型多光谱相机所用机械快门曝光时间波动对其光谱图像获取及处理造成的影响.通过对现有机械快门结构及驱动方法的研究,分析了造成该类机械快门稳定性差的原因,并提出了一种先进的机械传动方式和电路驱动方法.通过室内试验数据计算,该方案将两次曝光间的最大变化率从15.05％降低到0.96％,极大提高了曝光时间稳定性；通过外场推扫成像试验及数据处理,证明快门改进后多光谱相机所得彩色影像更接近真实目标,且无明显色彩突变.这对实际应用中多光谱相机数据处理结果的判读和目标识别具有重要意义.%The present paper analyzes the impact of mechanical shutter on the spectral image acquisition and processing of largearray filter-type multispectral imaging system.The final image quality relies highly on the mechanical shutter due to the fluctuation at exposure time.The conventional mechanical shutter's structure and driving method was analyzed to find out the key fact for its poor stability.An improved method of mechanical transmission and circuit driving was proposed.Laboratory experiments showed that with the improved design strategy,the maximum rate of change between adjacent exposures was reduced from 15.05％ to 0.96％,which is a great improvement of the exposure time stability.Field test was also carried out and the results show that the combined color images are closer to the realistic targets and no abrupt color change iwas found.It's of great significance for practical application in multispectral image process,interpretation and target identification.