基于红外热图像灰度修正的辐射测温

基于红外热像仪的测温精度依赖于大气温度、相对湿度、大气透射率、翻转表像温度等参数的测量精度。为了减少这种依赖性和提高测量精度,提出了一种基于红外热图像灰度修正的辐射测温方法。首先基于高精度面源黑体建立了红外热图像灰度修正模型,然后通过灰度修正模型对实测的目标灰度进行修正,最后通过基于加权最小二乘法建立的热像仪辐射定标模型等计算出修正后的目标亮度和温度。在实验室环境下,分别基于红外热像灰度修正辐射测温法和直接用热像仪测温对目标进行了测量。结果表明,在实验室环境下,前者的平均测量精度较后者提高了3.6%。该方法对实验室环境下红外测温有较好的实用价值,对外场红外测温也有一定的借鉴意义。

Radiation thermometry based on infrared thermal image gray correction

The measurement accuracy of infrared thermal camera depends on the measurement accuracy of atmospheric temperature,relative humidity,atmospheric transmission,reflected apparent temperature and so on.In order to minimize the dependency and improve the measurement accuracy,a radiation temperature measurement method based on infrared thermal image gray correction is proposed.At first,an infrared thermal image gray correction model is established using large extended area blackbody with high precision,and then target gray is amended based on this correction model.At last,the amended target radiance and temperature are calculated by infrared thermal camera calibration model based on weighted least square.Under the laboratory environment,the measurement experiments based on infrared thermal image gray correction and direct measurement using infrared thermal camera were carried out respectively.The results show that the mean measurement accuracy of the former improves by 3.6% compared with that of the latter,which has a good practical value for radiation thermometry.