紫外激光探测灰霾的后向散射回波特性

为了研究紫外激光探测灰霾的后向散射特性，基于Mie散射理论和蒙特卡洛方法，建立紫外激光后向散射探测灰霾模型，仿真灰霾条件下紫外激光的后向散射过程，并分析了不同宽度紫外激光脉冲后向散射回波的峰值功率、波峰时延和半高全宽等特征。研究结果表明，在一定灰霾浓度范围内，灰霾浓度越低，发射脉冲越窄时，激光回波畸变越明显，当发射脉冲宽度大于10 ns，激光回波近似呈高斯分布；在发射脉冲宽度相同的条件下，激光回波峰值功率和回波波峰时延随着灰霾浓度的增大而增大，回波半高全宽随着灰霾浓度的增大而减小，当发射脉冲宽度大于32 ns，回波峰值功率趋于平缓。文中研究成果可为紫外激光探测灰霾浓度及分析灰霾后向散射激光回波特性提供依据。

Backscattering echo characteristics of haze detected by ultraviolet laser

In order to study the backscattering characteristics of the haze by ultraviolet laser (UV laser), the UV laser backscattering model was established to simulate the backscattering process of UV laser under the haze conditions, based on Mie scattering theory and Monte Carlo method. The peak power, peak delay and full width at half maximum of the backscattered echoes of ultraviolet laser pulses with different widths were analyzed. The results show that, within the certain range of haze concentration, the lower haze concentration and the narrower the emission pulse width are, the more obvious the distortion of the laser echo waveform is. As the width of the emission pulse increases, when the emission pulse width is larger than 10 ns, the laser echo is approximately Gaussian distribution; Under the same emission pulse width condition, the peak power and echo peak delay of the laser echo increase with the increase of the haze concentration, and the full width at half maximum of the echo decreases with the increase of the haze concentration, When the emission pulse width is larger than 32 ns, the peak echo power tends to be flat. The results of this paper can provide a theoretical basis for UV laser detection of haze concentration and analyzing the echo characteristics of haze backscattered laser.