被动DOAS/CT在大气污染气体监测中的应用  

Detection of the atmospheric pollutant by using passive DOAS

作　　者：韦民红[1,2] 童敏明[1] 魏明生[1] 李素文[2] 

机构地区：[1]中国矿业大学信息与电气工程学院,江苏徐州221116 [2]淮北师范大学物理与电子信息学院,安徽淮北235000

出　　处：《安全与环境学报》2013年第3期167-170,共4页Journal of Safety and Environment

基　　金：国家自然科学基金面上项目(41275027);安徽高校省级自然科学研究项目(KJ2012Z343);淮北师范大学青年科研项目(2013xqz16)

摘　　要：为了对大气污染气体的空间分布进行实时监测,有效防治大气环境污染,设计了被动差分吸收光谱层析系统,通过差分吸收光谱技术(DOAS)获取大气污染气体的积分体积分数,再采用联合迭代重构算法(SIRT)得到其空间分布信息,通过数值模拟的方式加以验证。数值模拟结果表明,实践与理论相符,满足预期指标,且投影误差基本不影响重构图像的质量。试验结果表明,系统可以实现大气污染气体的二维空间分布监测。This paper is aimed to present our method for finding the atmospheric pollutant by using passive DOAS. For this purpose, we have introduced an optical tomography system based on the passive difference optical absorption spectrum （DOAS）, that is, how to do rea-l time monitoring activities with the spatial distribution of pollution gases in the atmosphere so as to prevent the atmosphere from being polluted effectively. The goal of the system is to employ the concentration profiles, rather than just a point value, of the pollutant gases concentrations. However, the reconstruction area （20×20 pixels） of the concentration of the pollutant gases are to be scanned while doing on-line monitoring activities by using two sets of passive difference optical absorption spectrum （DOAS） ratherthan one. In addition, 36 light paths are needed to be adopted in the form of the fan projection scheme to scan the area of the polluted gases. At the same time, it is to apply a novel image reconstruction algorithm, known as the simu-l taneous iterative reconstruction technique （SIRT）, to extract the data and information from the two passive DOAS systems. The disadvantage of the SIRT is slow in speed though some improvements have a-l ready been made by adding different relax factors to reduce the relative errors. The new system of ours can work out the integrated concentration of the gases with the difference optical absorption spectrum （DOAS） algorithm. Besides, we have also introduced the detection principle of difference optical absorption spectrum （DOAS） in the paper in a detailed way by means of numerical simulation for analyzing and evaluating the reconstruction effect. The results of trial application of our system showthatthe theory is conformedwiththe practice, with the maximum error of the optical tomography being 0.02, which proves to meet the expected indicators nicely. And, if the different random errors were added to the projection data, the results of our testing also indicate that the projection er

关 键 词：环境工程学 被动差分吸收光谱 光学层析 联合迭代重构算法 

分 类 号：X831[环境科学与工程—环境工程]