敦煌地区大气水汽和气溶胶对获取地表温度的影响

大气中的水汽和气溶胶含量是影响热红外波段数据的主要因素。针对敦煌地区，本文首先利用ＬＯＷＴＲＡＮ－７辐射传输模型对１９９２年９月２５日敦煌市西戈壁的一幅Ｌａｎｄｓａｔ－５ＴＭ６波段的热红外图像数据进行了大气订正，获取了地表辐射温度。进而利用ＬＯＷＴＲＡＮ－７通过模拟计算研究了该地区大气水汽和气溶胶含量的变化对ＴＭ６波段地面温度获取结果的影响，给出了对于热红外图像进行大气订正的主要判据。另外，文中还对热红外波段地面比辐射率的影响也进行了简单分析

Effects of Atmospheric Water Vapor and Aerosol on Retrievals of Land Surface Temperature in Dunhuang Site

Radiometric calibration of satellite-acquired data (visible, near-infrared and thermal infrared) is essential for quantitative scientific studies, as well as for a variety of quantitative appications. In the spectral region of thermal infrared,the effects of atmospheric water vapor and aerosols on the retrievalsof surface temperature are the two primary factors. From Landsat-5 TM6 image data acquired at Dunhuang site on September 25 1995, we made adjustments for atmospheric effects and derived the land surface temperatures using the spectrally corrected LOWTRAN-7 code. Using LOWTRAN-7 code, we also analyse the effects of atmospheric water vapor and aerosols on the retrieved surface temperatures by simulative calculations. Finally, we provided an explanation for what kinds of atmospheric conditions, even without considering the foreknown influence of the atmosphere, properly calibrated thermal infrared data can provide accurate remote temperature measumments, and determined under what meteorologic conditions, making corrections for atmospheirc effects is in need. This paper, at the end, also discussed the emissivity effects on the derived surface temperature.