应用激光雷达技术探测近地面大气无组织颗粒物具有重要的理论和应用价值。 将激光雷达技术应用于探测城市建筑工地扬尘，利用建筑外墙进行激光雷达信号的相对标定，然后根据激光雷达方程求解沿光学路径的扬尘颗粒物消光系数，通过程控扫描台获取多条路径上的消光系数分布，并结合质量消光效率因子得到二维质量浓度分布情况。结果表明，基于扫描平台的微脉冲雷达系统可以快速获取建筑扬尘二维分布和随时间变化情况，结合粒径谱和风速风向信息进一步得到重型车和小型施工车辆的PM10 排放因子分别为8.99×103 g/km和1.75×103 g/km； 重型车和小型施工车辆的PM2.5排放因子分别为4.57×102 g/km和8.91×101 g/km。该方法为城市扬尘快速实时监测提供了一种新思路。

Lidar is a powerful tool for detecting fugitive dust emissions. Here a method using vertical scanning micro pulse lidar (MPL) system to rapidly detect the two-dimensional mass distribution and the temporal variation of fugitive dust plumes in situ is descriped. In this method the backscattering signal from a building in the far field is used as reference to provide a closure condition to lidar equation. The dust plume′s extinction coefficient profiles are determined from the raw MPL signals by inverting the lidar equation. The extinction coefficient profiles are then converted to mass concentration profiles using mass extinction efficiency fator, which is determined by Mie model and simultaneous size distribution measurements. This method quantifies the spatial and temporal variation of the dust′s PM10 and PM2.5 mass concentration when the dust plume passes across the laser light path. In addition, PM10 and PM2.5 emission factors for heavy-duty and light-duty vehicles traveling in the construction field are determined using this method. The mean PM10 emission factors for the heavy-duty and light-duty vehicles are 8.99×103 g/km and 1.75×103 g/km, respectively; the mean PM2.5 emission factors for the heavy-duty and light-duty vehicles are 4.57×102 g/km and 8.91×101 g/km, respectively. This novel method provides an in-situ rapid way to measure PM mass emissions from urban fugitive dust sources.