1. Key Lab of Environmental Optics and Technology, Chinese Academy of Sciences, Anhui Institute of Optics and Fine Mechanics, Hefei 230031, China 2. Institute of Electronic Science and Technology, Anhui University, Hefei 230039, China
Abstract：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%.
Key words：FTIR;Cross section;Transmittance spectra;Selection of wave band
[1] Mosebacb H，rippel H，Bittner H，el al. Proc SPIE, 1990，1269：93. [2] Small G W，Harms A C，Kroutil R T，et al. Anal. Chem., 1990，62：1768. [3] ZHU Jun，LIU Wen-qing, LIU Jian-guo, et al( 朱 军，刘文清, 刘建国, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2005, 25(10): 1573. [4] GAO Min-guang，LIU Wen-qing，ZHANG Tian-shu，et al(高闽光，刘文清，张天舒，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2005, 25(7): 1042. [5] ZHU Jun, LIU Wen-qing, LU Yi-huai, et al(朱 军，刘文清, 陆亦怀, 等). Optical Technique(光学技术), 2005，31(4): 627. [6] Rothman L S, Rinsland C P, Goldman A, et al. J. Quant. Spectrosc. Radiat. Transfer, 1998, 60：665. [7] Esler M B, Griffith D W T, Wilson S R, et al. Anal. Chem., 2000, 72(1): 206.
