Novel infrared differential optical absorption spectroscopy remote sensing system to measure carbon dioxide emission

A CO_2 infrared remote sensing system based on the algorithm of weighting function modified differential optical absorption spectroscopy(WFM-DOAS) is developed for measuring CO_2 emissions from pollution sources. The system is composed of a spectrometer with band from 900 nm to 1700 nm, a telescope with a field of view of 1.12?, a silica optical fiber, an automatic position adjuster, and the data acquisition and processing module. The performance is discussed,including the electronic noise of the charge-coupled device(CCD), the spectral shift, and detection limits. The resolution of the spectrometer is 0.4 nm, the detection limit is 8.5 × 10^(20)molecules·cm^(-2), and the relative retrieval error is < 1.5%.On May 26, 2018, a field experiment was performed to measure CO_2 emissions from the Feng-tai power plant, and a twodimensional distribution of CO_2 from the plume was obtained. The retrieved differential slant column densities(dSCDs)of CO_2 are around 2 × 10^(21) molecules·cm^(-2) in the unpolluted areas, 5.5 × 10^(21)molecules·cm^(-2) in the plume locations most strongly affected by local CO_2 emissions, and the fitting error is less than 2 × 10^(20)molecules·cm^(-2), which proves that the infrared remote sensing system has the characteristics of fast response and high precision, suitable for measuring CO_2 emission from the sources.

基于短波红外波段吸收技术的CO2垂直柱浓度地基遥测反演方法研究

温室气体引起的全球变暖、气候变化等问题已成为国际关注的热点,其中CO_2是重要的温室气体之一,CO_2的监测与控制已经成为各国关注的重点。结合CO_2在1.6μm处的光谱吸收结构,利用加权函数修正的差分吸收光谱技术(weighted function modified difference absorption spectroscopy,WFM-DOAS)研究大气中CO_2垂直柱浓度的反演方法。利用大气辐射传输模型仿真研究了不同参数对加权函数(weighted function,WF)计算灵敏度的影响,分别对观测高度、太阳天顶角、太阳方位角、地表反照率、光谱分辨率等参数对CO_2WF系数的影响进行了详细的计算分析。并以一整天测量的太阳光为例,对仪器的性能、CO_2的垂直柱浓度及干扰气体CH_4及H_2O的垂直柱浓度进行了分析,初步分析得到的反演误差优于1%。