Simultaneous detection of multiple gaseous pollutants using multi-wavelength differential absorption LIDAR

Abstract

Differential absorption LIDAR (DIAL) is an effective way to remotely detect air pollutants and hazardous chemicals in the atmosphere. Based on the traditional dual-wavelength DIAL theory and previous studies, simultaneous measurement of multiple pollutant gases in the atmosphere using a multi-wavelength differential absorption LIDAR (MW-DIAL) is reported. It can measure a variety of harmful chemicals in the environment and improve the precision of the technology. A prototype was demonstrated using a tunable Transversely Excited Atmospheric (TEA) CO2 laser working in the 9–11μm band. The prototype could accurately detect NH3, CH3OH, and O3 simultaneously in a detection and measurement, with correlation coefficients of 0.967, 0.981, and 0.949, respectively. Simulations and the evaluation experiment proved the feasibility of the MW-DIAL detection method for multiple pollutant gases in the atmosphere. The field test showed that the MW-DIAL can be utilized to identify and detect the target gas at a 5-km-distance.