本文主要介绍了一种快速测量区域大气痕量气体二维分布的方法——机载成像差分吸收光谱(differential optical absorption spectroscopy,DOAS)技术.该技术基于成像光谱仪,利用DOAS算法,对痕量气体大范围分布快速扫描成像,可实现污染源扩散趋势的可视化观测,应用于污染源定位、污染源排放率监测、污染物传输演化等研究.文中详细介绍了研制的机载成像DOAS系统,并利用该系统开展飞行实验,快速获取了飞行轨迹上空的NO2浓度分布.实验中针对重点关注区域进行扫描测量,成功获取了高分辨率的NO2二维分布图,分析了污染扩散趋势,并结合风场数据,估算污染点源的NO2排放率为1570 kg/h.
The airborne imaging DOAS(differential optical absorption spectroscopy) method which can obtain two-dimensional distributions of trace gas is introduced in this paper. Based on this method, pollution source in a wide range of area can be found quickly, and a map of trace gas distribution can be obtained to study the pollutant diffusion tendency. In this paper we report the flying experiment over Tianjin and Tangshan. The airborne imaging system is introduced in detail and an image of two-dimensional NO2 distributions is obtained with a resolution of about 30 m × 80 m. Combined with wind field data, the emission rate of a point source on the flight path is calculated to be 1570 kg/h.