有机气溶胶的微脉冲荧光激光雷达水平近场探测研究

Micro-pulse Lidar (MPL) technology is an important means of atmospheric aerosol observation, laser-induced fluorescence signals can be used to detect organic aerosols in the environment when using ultraviolet laser light sources. A simulation model for the horizontal detection of organic aerosols by micro-pulse fluorescence lidar (MPFL) is established, and the number of echo photons and signal-to-noise ratio are numerically calculated. According to the simulation results, a micro-pulse fluorescence lidar was designed and built, and the intensity error of the near-field fluorescence echo signal was reduced by calibrating the geometric overlap factor of the system. The test experiment of the lidar system was carried out using the nutritional broth solution as the aerosol sample, and the experiments showed that the spatial resolution of the MPFL system was 7. 5m, and themaximum detection distance of the experiment reached 200m. At the same time, a comparative experiment was carried out with another fluorescence lidar with low repetition frequency and high pulse energy, and the comparison results showed that the trend of fluorescence signal intensity received by the two types of lidar had good consistency, and the correlation coefficient was more than 82%. Under the same accumulation time, the standard error of the MPFL fluorescence signal change rate matrix was less than 0. 02%, which had better antiinterference performance, and could achieve accurate detection of organic aerosols, which verified the effectiveness and practicality of the system.