Studies of a scanning light detection and ranging for three-dimensional detection of plume emission

Abstract

Aerosol plays an important role in regularization of the earth’s energy balance. Compared with light detection and ranging (LIDAR) pointing vertically, scanning LIDAR is a useful tool for detection of the spatial and temporal distribution of aerosols. A scanning LIDAR is constructed in which a compact 532-nm laser is bound to the telescope. Under the command from the serial port, the LIDAR can observe in different scanning modes. We introduce the structure and key parameters of the scanning LIDAR, and then verify its measurement ability by comparison with the Rayleigh–Raman–Mie LIDAR. Observation of a plume emission from a chemical factory is conducted in the northern suburbs of Nanjing, China. In order to obtain the distribution of the plume emission, the slope method and Fernald method are combined to invert the extinction coefficient of the plume. Analysis of the data shows that the scanning LIDAR can be used to monitor the relative emission concentrations of pollutants and depict the process of the pollutants’ diffusion. The scanning LIDAR can also be used to measure the three-dimensional variation of the extinction coefficient by automatic volume scanning.