以水云后向散射系数为边界值的激光雷达气溶胶后向散射系数反演方法

Inversion Algorithm of Aerosol Backscattering Coefficient with Water Cloud Particle Backscattering Coefficient as Boundary Value

结合毫米波雷达和双波长激光雷达对水云粒子进行微物理特性和光学特性建模,构建水云粒子有效半径与反射率因子-消光比、反射率因子-后向散射比的关系。通过假设参考高度处的云滴粒子有效半径和下一个距离门处的雷达比,以双波长反演的有效粒子半径和后向散射系数反演误差为约束条件得到边界值处的后向散射系数。进而,利用Fernald后向积分方法反演水云天气下的气溶胶后向散射系数廓线。仿真结果与所提方法处理后的粒子有效半径一致性系数为0.98,与双波长后向散射系数的一致性系数均为0.81。实际处理结果表明,所提方法能够改善水云天气下气溶胶反演的连续性,得到相对准确的后向散射系数。

We propose a millimeter-wave radar and dual-wavelength lidar combined model for the microphysical and optical properties of water cloud particles.On this basis,we build the relationships of the effective radius and reflectivityextinction ratio,as well as reflectivity-backscattering ratio of water cloud particles.Assuming the effective radius of the cloud droplet at the reference height and the lidar ratio at the next range gate,we can obtain the backscattering coefficient at the boundary value using the effective radius and backscattering coefficient inversion errors by dual-wavelength as constraints.Moreover,we employ Fernald backward integration method for the inversion of the aerosol profiles under water cloud conditions.The correlation coefficient between the simulated effective radius and that after algorithm processing is 0.98,and the correlation coefficient of the dual-wavelength backscattering coefficient is 0.81.The case studies indicate that this method can give rise to better inversion continuity of aerosols under water cloud conditions and a relatively accurate backscattering coefficient.