研制了一套可用于探测背景大气SO2和NO2的差分吸收激光雷达系统。该系统利用两台Nd∶YAG激光器的二倍频和三倍频产生532 nm/355 nm的激光, 分别去抽运四台窄线宽的染料激光器, 从而获得测量大气SO2和NO2分布所需的两对激光波长300.05 nm/301.5 nm和446.6 nm/448.1 nm。实验数据表明, 在晴朗的天气条件下, 当空间分辨率为15 m且积分时间为30 min时, 大气SO2和NO2的测量精度分别可达±2.0×10-9和±5.0×10-9, 激光雷达探测的大气SO2和NO2平均浓度与当地气象部门同时间报告的浓度较一致, 显示了差分吸收激光雷达技术监测低浓度SO2和NO2时空分布的能力。

A differential absorption lidar (DIAL) system has been developed for background atmospheric SO2 and NO2 measurements. Second harmonic and third harmonic (532 nm/355 nm) of two Nd∶YAG lasers are used to pump four dye lasers, respectively. Two pairs of laser beams 300.05 nm/301.5 nm and 446.6 nm/448.1 nm are obtained for profiling atmospheric SO2 and NO2. Observation results show that accuracies of atmospheric SO2 and NO2 measurements under clear weather condition can be within ±2.0×10-9 and ±5.0×10-9, respectively, when spatial resolution is set to 15 m and integration time is seted to 30 minutes. Averaged atmospheric SO2 and NO2 concentrations observed through SO2/NO2 DIAL conform with the results of meteorological department at the same time. It shows that DIAL technique has the ability to measure the space-time distribution of low concentration of SO2 and NO2.