大气对生物气溶胶激光雷达性能影响的仿真分析

Abstract

obtained to provide sufficient atmospheric data for the following simulation of the system performance. Finally, the signaltonoise ratio of the total fluorescence spectroscopy system (Fig. 9) and the that of the 360 -370 nm channel system (Fig. 10) are calculated.The results show that the atmospheric conditions largely affect the detection performance of the system : the higher the atmospheric visibility, the longer the effective detection distance of the system. Comparing the two atmospheric environments of visibility of 23 km and 3 km, the difference in the effective detection distance for different working hours is 2 -4 times. The working hours of the system also have a great impact on the detection performance. The detection performance of the system during daytime is poor and the difference between different time periods is small, while the effective detection distance of the system is generally increased (at least doubling) at night because the intensity of the atmospheric background radiation is greatly reduced, and the higher the atmospheric visibility, the larger the increase. Under the visibility of 23 km, the effective detection distance at night is 3.7 times that at the daytime. At the same time, the effective detection distance of the aerosol biological detection based on the total fluorescence intensity is higher than that of the aerosol biological component identification based on the spectrally distinguishable fluorescence intensity, and the former is more significantly affected by atmospheric conditions, i. e., good atmospheric conditions will bring higher improvement to the aerosol biological detection function.Conclusions In this paper, the detection performance of LIF lidar under different atmospheric conditions is evaluated through simulations. The LIF lidar is suitable for biofluorescence measurements at night because of the high atmospheric background radiation intensity in the fluorescence band. The decrease of atmospheric visibility leads to the decrease of background radiation intensity and also the decrease of transmittance of broad fluorescence spectrum , which in turn leads to the decrease of LIF lidar detection performance, but the influence is far less than the effect of changing operating hours between daytime and night. The most suitable working environment for LIF lidar is the night with high visibility.