应用内外定标修正实现红外测量系统辐射定标

由于现有的大口径短波红外测量系统的辐射定标需要制备大口径红外平行光管,不仅机动性差且成本较高,故提出了一种基于内、外定标修正的辐射定标新方法。该方法将一个中、高温腔型黑体置于红外系统内部,通过切换反射镜,将中、高温腔型黑体辐射引入红外光学系统,并对部分光路进行中、高温段的内定标。然后,使用大面源黑体对全系统进行中温段的外定标;提取并处理公共温度范围的内、外定标数据以获取内、外定标之间的修正系数。最后,对中、高温段的内定标数据进行修正从而获取全系统的辐射定标数据。使用该方法对某Φ400mm口径的红外测量系统进行了辐射定标,并根据定标结果反演了黑体的辐射亮度和温度。结果显示:辐射亮度反演的最大误差为1.67%,温度反演的最大误差为1.02℃。实验结果证明了该方法可以准确、有效地对大口径短波红外测量系统进行辐射定标。

Radiation calibration of infrared system by amendment of inner and outer calibrations

As the existing radiation calibration for a shortwave infrared system with large aperture needs a huge infrared collimator and has poor motility and cost much, this paper proposes a new calibration method based on the amendment of inner and outer calibrations. This method sets a middle-high temperature cavity blackbody in the infrared system. By switching a mirror, it introduces the blackbody radiation into the infrared system to implement the inner calibration on parts of system at the middle-high temperature range. Then it uses a huge area blackbody to implement the outer calibration on the whole system at middle temperature range. The inner and outer calibration data at the common temperature range are picked up to calculate the amendatory coefficient in whole system. Finally, the radiation calibration data for whole system at the middle-high temperature range are captured by amending the inner calibration data. With this method, an Φ400 mm infrared system is calibrated, and the luminance error and temperature error are inverted based on the calibration results. The results show that the maximal luminance error is 1.67% and the maximal temperature error is 1.02 ℃. The results indicate that the proposed method is precise and effective for the radiation calibration of shortwave infrared systems with large apertures.