大口径、宽动态范围红外测量系统辐射定标方法

Radiation Calibration Method for Infrared System with Large Aperture and Broad Dynamic Range

现有的大口径、宽动态范围红外测量系统的辐射定标需要制备大口径红外平行光管,该方法机动性差且成本较高。为了解决这一问题,提出了一种基于内、外定标修正的辐射定标新方法。该方法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;使用面源黑体对全系统进行中、低温段的外定标;提取公共温度范围的内、外定标数据并处理以获取内、外定标之间的修正系数;对中、高温段的内定标数据进行修正可以获取全系统在中、高温段的辐射定标数据,结合外定标结果就得到了全系统、宽动态范围的辐射定标数据。使用该定标方法对某Φ400mm口径的红外测量系统进行辐射定标,并根据定标结果反演黑体的辐射亮度和温度,辐射亮度反演的最大误差为1.35%,温度反演的最大误差为0.76℃,实验结果证明了该定标方法的有效性。

The existing radiation calibration for infrared system with large aperture and broad dynamic range needs huge infrared collimator, but this method has poor motility and cost much. In order to settle this question, a new calibration method basing on the amendment of inner and outer calibration is put forward. This method set a middle- high temperature cavity blackbody in infrared system, with the help of switching reflector, the cavity blackbody radiation is imported into optics system for the inner calibration on parts of system at middle-high temperature range, and an extended source blackbody is needed for the outer calibration on the whole system at middle-low temperature range. The inner and outer calibration data at common temperature range are picked up to calculate the amendatory coefficient. In the end, the whole system＇s radiation calibration data at the middle-high temperature range are caught by amending the inner calibration data. Combining the outer calibration data at the middle-low temperature range, the whole system＇s radiation calibration data at broad dynamic range are gained. Carrying through this method on an 0400 mm infrared system and calculating the luminance error and temperature error, the maximal luminance error is 1.35% and the maximal temperature error is 0.76℃, the results indicate that the proposed method is effective.