差分吸收激光雷达测量环境SO_2

Differential Absorption Lidar for Environmental SO_2 Measurements

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 2 6 6 .0nm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 2 88.38nm和 2 89.0 4 nm。SO2 对波长为 2 89.0 4nm的激光吸收较强 ,对 2 88.38nm的激光吸收较弱 ,波长对 2 88.38nm和 2 89.0 4 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 SO_2 measurements. The fourth harmonic of Nd∶YAG laser was used to pump CH_4 and D_2 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 SO_2, 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 SO_2 concentrations. Based on this technique, a SO_2 DIAL was constructed. SO_2 actual measurements and primary studies were also carried out at lidar located site. Measurement errors were analyzed and evaluated. SO_2 concentrations measured by SO_2 DIAL are comparable with results obtained by SO_2 analyzer.