红外整层大气透过率测量方法研究

Study on Measurement Method for Total Infrared Atmospheric Transmittance

提出了基于大气辐射传输方程的红外大气透过率测量方法,使用中波红外辐射亮度测量装置在青海德令哈和北京怀柔对红外大气透过率进行了实测验证;并与模型计算结果进行了对比。只需在短时间内精确测量不同天顶角处的大气辐射亮度,采用大气辐射传输方程对测量数据进行拟合,即可得到测试波段整层大气透过率。实测结果:德令哈大气透过率0.730,相对不确定度2.4%;怀柔大气透过率0.625,相对不确定度0.8%。此测量方法不需使用大口径望远镜,简便易行;更重要的是测量不基于大气外的标准星,透过率测量精度不受标准星亮度精度的影响。

An infrared atmospheric transmittance measurement method based on the atmospheric radiative transfer equation is proposed.The infrared transmittance of the atmosphere was measured in Delingha,Qinghai and Huairou,Beijing.The results were compared with the calculated results obtained with a model.The atmospheric radiance at varying zenith angles was accurately measured within a short timeframe.The atmospheric transmittance was obtained by fitting the measurement data with the atmospheric radiative transfer equation.The measurement results show that the atmospheric transmittance in Delingha was 0.730,with a relative uncertainty of 2.4%.The atmospheric transmittance in Huairou was 0.625,with a relative uncertainty of 0.8%.The proposed method is very convenient because it does not require a large-aperture telescope.More importantly,the method is independent of standard stars.The accuracy of the transmittance measurement is not affected by standard stars.