基于直射太阳光红外吸收光谱技术的大气中CH4柱浓度遥测研究

为了研究甲烷气体柱浓度探测方法，文中介绍了一种基于直射太阳光红外吸收光谱技术的遥测系统，并利用该系统在合肥地区进行了连续观测。从太阳吸收光谱中实时测量了整层大气透过率；采用逐线积分方法模拟计算了整层大气透过率；基于非线性最小二乘光谱反演算法从实测整层大气透过率中反演了甲烷气体柱浓度和氧气柱浓度，并以氧气柱浓度为内标函数获得了甲烷干空气柱体积混合比，精密度优于2%。将本系统测量的2012年9月25日12时到15时CH4干空气柱体积混合比均值与此时段过境本站点区域的日本温室气体卫星的CH4观测结果进行了比较，两者偏差小于1%。可见,该系统和方法是一种有效的甲烷气体柱浓度探测系统和方法，具有较高精度。

Remote sensing of CH4 column concentration in the atmosphere based on direct sun infrared absorption spectroscopy

A remote sensing system was developed based on direct-sun infrared absorption spectroscopy in order to study the detection method of Methane column concentration, which was running continuously in Hefei. The total atmospheric transmittance was real-timely measured from the solar absorption spectrum and modeled by line-by-line calculation. The column concentrations of Methane and oxygen were inversed from measured total atmospheric transmittance by nonlinear least squares spectral inversion algorithm. The column concentration of oxygen was used as internal standard function to obtain column-average dry-air mole fractions of Methane and the precision was better than 2%. The column-average dry-air mole fractions of Methane, from 12:00 to 15:00 on September 25, 2012, were compared with Methane results observed by Japanese greenhouse-gases satellite over this site at this period, showing that the relative deviation was less than 1%. Obviously, this system and algorithm are an effective way to detect Methane column concentration with higher precision.