Airborne and Ground-Based Measurement of Atmospheric Aerosol Backscatter at CO2 Laser Wavelengths

Measurement of atmospheric winds by lidars is dependent upon receiving sufficient reflected laser radiation to allow reliable velocity estimates. The signal intensity is in turn dependent on the "reflectivity" of the atmosphere. However, this "reflectivity" (more properly termed atmospheric backscatter coefficient) is not constant, but rather varies with geographic location, season, altitude, etc. There are several ways that the reflectivity may be estimated - extrapolation from visible and near-ir backscatter, extinction measurements, and particle sizing and prediction based on Mie theory.