[FTIR measurement and analysis based on the selection of optimized spectral band].
In active infrared remote sensing measurements, the infrared absorption caused by the presence of trace gases in atmosphere is related to the transmittance spectra in different infrared wave band. In many cases, transmittance spectra play an important role in spectsal quantitative analysis. Thus, the selection of wave band to be optimized for the measured and simulated transmittance spectra is the key in quantitative analysis. In the present paper, the optimal measurement range of transmittance is analyzed theoretically, which causes the minimum relative error of the retrieved concentration. The cross section for the measured gas based on Lorentz line shape is derived by calculation. At the same time, the transmittance spectra calibration training set is presented. The measured and analyzed band is determined for single component CO2. The optimal measurement band is determined for multi-component measurement. The simultaneous measurement of CO, CO2 and N2O with open path FTIR spectrometer system is accomplished successfully. The measured transmittance spectra are in good agreement with the reference transmittance spectra. The root mean square error of fitting results is less than 1%.
Zhu
Jun
J
Key Lab of Environmental Optics and Technology, Chinese Academy of Sciences, Anhui Institute of Optics and Fine Mechanics, Hefei 230031, China. zj2003@aiofm.ac.cn
Liu
Wen-Qing
WQ
Liu
Jian-Guo
JG
Lu
Yi-Huai
YH
Gao
Min-Guang
MG
Xu
Liang
L
Zhang
Tian-Shu
TS
Wei
Xiu-Li
XL