title: Measurement of the azimuthal dependence of cross-polarized lidar returns and its relation to optical depth.
abstract: We measure with a gated intensified CCD camera the cross-polarized backscattered light from a linearly polarized laser beam penetrating a cloud made of spherical particles. In accordance with previously published results we observe a clear azimuthal pattern in the recorded images. We show that the pattern is symmetrical, that it originates from second-order scattering, and that higher-order scattering causes blurring that increases with optical depth. We also find that the contrast in the symmetrical features can be related to measurement of the optical depth. Moreover, when the blurring contributions are identified and subtracted, the resulting pattern provides a pure second-order scattering measurement that can be used for retrieval of droplet size.
authors.affiliation: Defence Research and Development Canada Velcartier, 2459 Pie XI Boulevard North, Val-Belair Quebec, Canada G3J 1X5. nathalie.roy@drdc-rddc.gc.ca
authors.forename: Nathalie
authors.initials: N
authors.lastname: Roy
authors.forename: Gilles
authors.initials: G
authors.lastname: Roy
authors.forename: Luc R
authors.initials: LR
authors.lastname: Bissonnette
authors.forename: Jean-Robert
authors.initials: JR
authors.lastname: Simard