A Method of Inversing Dynamic Aerosol Extinction-to-Backscattering Ratio Based on Lidar Echo Signal and Ground Aerosol Extinction Coefficient or Aerosol Optical Depth

Abstract

When using the Fernald method to solve the lidar equation, the selection of aerosol extinction-to-backscattering ratio (lidar ratio) is an important error source, which becomes a major factor limiting the accuracy of aerosol extinction profile. Therefore, we proposed a method for dynamic lidar ration inversion, named iteration inverse generation method (IIGM). This method is based on the Fernald method, takes the ground extinction coefficient as the loop iteration constraints, and is combined with the lidar signal to inverse the local dynamic lidar ratio. The local lidar ratio obtained by IIGM is in the range of 10–50 sr. The average relative error between the ground extinction coefficient inversed from dynamic lidar ratio and the measured ground extinction coefficient is 0.0041%. The relative error between the inverse aerosol optical depth (AOD) and the measured AOD is 20.38%. In addition to using the ground extinction coefficient as the iteration constraints of IIGM, AOD is introduced as another optional iterative constraint. The IIGM can achieve accurate inversion of lidar signals in different situations.