摘要
采用实验室中四杆靶红外目标源,使其成像在热成像系统自身的焦面探测器上,采用放大倍率法测量与计算出系统的焦距。由于热成像系统的探测器像元尺寸一般较CCD像元大,为了降低像元尺寸对测量精度的影响,根据误差理论,合理选择四杆靶目标,使其能够达到满意的测试精度。这种焦距测量方法,原理简单直接,测量范围大,对于热成像系统的检测与装调,有着很好的实际应用价值。文中详细分析了影响焦距测量不确定度的因素,焦距的测量扩展不确定度可达到U=0.4%。
The focal length of a thermal imaging system was assessed by the magnification method using 4-bar targets as infrared objectives. However, the detector pitch is larger than that of CCD detector and limits the measurement accuracy. In order to improve the accuracy, appropriate 4-bar targets are chosen according to academic calculation. The uncertainty effects in measurement was analyzed and the uncertainty in measurement can reach U = 0.4%.
出处
《红外技术》
CSCD
北大核心
2006年第4期220-223,共4页
Infrared Technology
关键词
焦距
四杆靶图像
放大倍率法
热成像系统
Focal length. 4-bar image
Magnification method
Thermal imaging system
