校准红外热像仪的双黑体准直光管辐射源设计

Design of Double Black Body Collimating Light Tube Radiation Source for Calibrating Infrared Thermal Imager

为了校准红外热像仪的成像特性参数,设计了一种双黑体准直光管辐射源。采用反射式光学系统设计,解决了传统的透射式光学系统难以消除色差的问题,其工作谱段能够覆盖0.38~12μm宽光谱范围。靶标组件采用反射靶形式,通过目标自校准黑体辐射源和背景自校准黑体辐射源之间的共同作用,实现对热特性目标的模拟,并可以杜绝差分靶标的温升现象。该辐射源经国家法定计量技术机构检测,满足设计要求。利用该辐射源对某型红外热像仪成像特性参数进行了校准验证,结果显示,该辐射源可用于黑体温度范围5~100℃,差分温度范围-15~45℃的红外热像仪的信号传递函数(SITF)、噪声等效温差(NETD)和最小可分辨温差(MRTD)等参数的自动测试,温差不确定度为0.02℃,能够广泛应用于各种型号红外热像仪的校准。

In order to calibrate the imaging characteristic parameters of the infrared thermal imager,a double black body collimating optical tube radiation source is designed.The reflection optical system is used to solve the problem that the transmission optical system is difficult to eliminate the color difference.Its working spectrum can cover a wide spectral range of 0.38~12μm.The target assembly adopts the form of reflecting target.Through the interaction between the target self-calibrated blackbody radiation source and the background self-calibrated blackbody radiation source,the thermal characteristics of the target are simulated,and the temperature rise of differential targets can be eliminated.The radiation source has been tested by the national legal metrological technical institution and meets the design requirements.The radiation source is used to calibrate and verify the imaging characteristic parameters of a type of infrared thermal imager.The results show that it can be used for automatic testing of SITF,NETD and MRTD parameters of infrared thermal imagers with blackbody temperature range of 5℃ to 100℃ and differential temperature range of-15℃ to 45℃.The uncertainty of temperature difference is 0.02℃.