中波红外探测器辐射定标的简化方法

Simplifying method of radiance calibration for MWIR detector

为了提高红外辐射定标效率,提出了简化的辐射定标方法。首先,提出带有积分时间变量的辐射定标数学模型,通过探测器像元响应灰度值随积分时间的变化曲线以及随黑体辐射亮度的变化曲线确定了辐射定标模型的具体形式,并介绍了模型中各参数的物理意义。接着,在不同环境温度下进行辐射定标实验,绘出辐射定标模型中各未知参数随环境温度的变化曲线,实验结果验证了辐射定标模型的正确性。然后,在这个模型的基础上提出了简化的辐射定标模型,即使用一元线性回归分析方法选择两个定标点,在两个典型的积分时间下采集这两个定标温度点的共四幅图像,经处理即可获取辐射定标模型的各未知参数。最后对通过辐射定标模型计算得到的辐射定标数据与实际定标获取的辐射定标数据进行比较分析。实验结果表明:计算值与定标值之间的误差优于1%。辐射定标模型准确,可以极大地提高辐射定标的效率。

In order to enhance the efficiency of infrared radiation calibration, a simple calibration method was brought forward. First, the radiation calibration model comprising integral time was put forward. Through the relation between integral time and cell′s response gray in company with the relation between blackbody′s radiation luminance and cell′s response gray, the concrete form of radiation calibration model was confirmed, and physics meaning of parameters in the formula were introduced. The radiation calibration experiments at different environmental temperature were processed and the changes of the unknown parameters with environmental temperature were plotted. The experiment results validate the radiation calibration model. A simple method for radiation calibration basing the model was brought forward, choosing two calibration points with the help of unitary linear regression method and collecting the two calibration points at two typical integral times, then the unknown parameters in the radiation calibration model were calculated through these four figures. Finally, comparison between the calibration data caught by calculating employing the model and actual calibration data caught by calibrating were took on. Experimental results indicate that the error between calculating and calibrating is small than 1%. The radiation calibration model is correct and the calibration efficiency could be boosted greatly.