Examination of the traditional raman lidar technique. II. Evaluating the ratios for water vapor and aerosols.
In a companion paper [Appl. Opt. 42, 2571 (2003)] the temperature dependence of Raman scattering and its influence on the Raman and Rayleigh-Mie lidar equations were examined. New forms of the lidar equation were developed to account for this temperature sensitivity.Here those results are used to derive the temperature-dependent forms of the equations for the water vapor mixing ratio, the aerosol scattering ratio, the aerosol backscatter coefficient, and the extinction-to-backscatter ratio. The error equations are developed, the influence of differential transmission is studied, and several laser sources are considered in the analysis. The results indicate that the temperature functions become significant when narrowband detection is used. Errors of 5% and more can be introduced into the water-vapor mixing ratio calculation at high altitudes, and errors larger than 10% are possible for calculations of aerosol scattering ratio and thus of aerosol backscatter coefficient and of extinction-to-backscatter ratio.
Whiteman
David N
DN
NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771, USA. david.n.whiteman@nasa.gov