Use of polarimetric lidar for the study of oriented ice plates in clouds

A polarization lidar operating at 532 nm was converted into an automatic, polarimetric lidar capable of measuring the entire Stokes vector of backscattered light and its derived quantities. Among these quantities, circular and linear depolarizations were studied as tools for investigating the presence of anisotropic scattering media. Isotropic scatterers show a simple relationship between linear and circular depolarization, a relation that we confirm theoretically and experimentally. Deviations from this relation, which are possible in the presence of anisotropic scatterers such as horizontally oriented ice plates when they are observed with a slant lidar, were studied both numerically and experimentally.