提出了一种新的差分吸收激光雷达(DIAL)技术探测大气环境SO2。利用Nd:YAG激光器的四倍频266.0 nm抽运甲烷和氘气,可以获得它们的一级斯托克斯拉曼频移波长288.38 nm和289.04 nm。SO2对波长为289.04 nm的激光吸收较强,对288.38 nm的激光吸收较弱,波长对288.38 nm和289.04 nm可用于大气SO2的测量。利用这种技术,建立了一台测量大气SO2的差分吸收激光雷达,并进行了实际测量和初步研究,对激光雷达测量SO2误差的主要来源进行了分析,并估计了测量误差的大小。差分吸收激光雷达的测量结果与仪器测量结果相比具有可比性。

In this paper a new technique of differential absorption lidar (DIAL) was presented for environmental SO2 measurements. The fourth harmonic of Nd:YAG laser was used to pump CH4 and D2 gas cell, and their first Stokes Raman-shifted wavelengths of 288.38 nm and 289.04 nm were gotten. Laser beam of 289.04 nm is rather strongly absorbed by SO2, but another laser beam of 288.38 nm is weakly absorbed. This wavelength pair of 288.38 nm and 289.04 nm can be used to measure environmental SO2 concentrations. Based on this technique, a SO2 DIAL was constructed. SO2 actual measurements and primary studies were also carried out at lidar located site. Measurement errors were analyzed and evaluated. SO2 concentrations measured by SO2 DIAL are comparable with results obtained by SO2 analyzer.