环境温度对红外辐射测量精度的影响及修正

摘要

为了提高靶场红外系统的辐射特性测量精度，找出外场复杂环境温度变化对测量精度的影响并进行相应地修正。首先，建立了红外系统辐射定标的数学模型，模型中包含杂散辐射噪声影响和内部暗电流噪声的影响。接着，通过在高、低温箱内进行辐射定标实验，找出环境温度变化对辐射定标模型中各参数的影响。实验结果表明：环境温度改变引起的杂散辐射变化对辐射特性测量精度有较大影响。同时发现，环境温度变化时，杂散辐射引起的探测器像元灰度输出变化量近似等于实测的全系统像元灰度变化量，最后根据这一结论提出一种简易的适合外场应用的红外系统辐射定标数据修正方法，采用这种方法，以70℃黑体为目标，在0～50℃的温度范围内，黑体温度测量误差的均方根由0.8℃降低到0.095℃。在不增加操作难度的同时，大大地提高了外场红外辐射特性测量精度。%In order to enhance the radiation characteristic measurement precision of infrared system,the influence of the complex temperature change at field condition on the measurement precision is found out and corrected corre-spondingly.Firstly,the model for infrared radiation calibration is constructed,which includes influences of stray radia-tion noise and inner dark current,and the effect of temperature variety on the parameters of infrared radiation calibra-tion is found out through the experiment carried in the high/low temperature test chamber.Experimental results show that the stray radiation variety caused by environmental temperature variety is the dominant factor for infrared radiation measurement precision,and at the same experiment,it is found that the gray variety caused by stay radiation is equal to the whole infrared system’s gray variety when the environmental temperature changes,and based on this conclu-sion,a simple means for field infrared calibration data correction is put forward.Adopting this method,the blackbody at 70℃ is measured,the RMS error of blackbody temperature measurement is able to reduce from 0.8℃ to 0.095℃within the temperature range of 0~50℃,which enhances the measurement precision greatly without increasing the op-erational difficulty.