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 aerosoloptics properties (back- scatter/extinction coefficients) from elastic-Raman lidardata is presented. Aerosol backscattercoefficients 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 aerosollayers and clouds appear there. Significant retrieval errors in aerosol backscattercoefficients caused by large uncertainties of the aerosolreference value at far-range can be reduced. To avoid the ill-posed retrievals of aerosolextinction from the conventional Raman method, the new method derives the aerosolextinction and lidarratio with the constrained Fernald inversions by independent aerosol backscattercoefficients from above proposed method. The numerical simulations demonstrated that the proposed method pro- vides good accuracy and resolution of aerosolprofile ret- rievals. And the method is also applied to elastic-Raman lidarmeasurements at the Hampton University, Hampton, Virginia.