Improved method to retrieve aerosol optical properties from combined elastic backscatter and Raman lidar data

An improved method that has the potential to improve the retrieval of aerosol optics properties (backscatter/extinction coefficients) from elastic-Raman lidar data is presented. Aerosol backscatter coefficients can be retrieved by choosing the reference height at near-range rather than conventional far-range when the signal-to-noise ratios are low at the far-range or aloft aerosol layers and clouds appear there. Significant retrieval errors in aerosol backscatter coefficients caused by large uncertainties of the aerosol reference value at far-range can be reduced. To avoid the ill-posed retrievals of aerosol extinction from the conventional Raman method, the new method derives the aerosol extinction and lidar ratio with the constrained Fernald inversions by independent aerosol backscatter coefficients from above proposed method. The numerical simulations demonstrated that the proposed method provides good accuracy and resolution of aerosol profile retrievals. And the method is also applied to elastic-Raman lidar measurements at the Hampton University, Hampton, Virginia.