Detection of stratospheric sulfuric Acid aerosols with polarization lidar: theory, simulations, and observations.

The derivation of backscatter ratio profiles from polarization lidar measurements is discussed. The method is based on differences in depolarization between molecular backscattering and backscattering from spherical aerosol particles. Simulations show that the polarization algorithms yield backscatter ratios with uncertainties comparable with those obtained by Klett's method, provided that the backscattering process is dominated by molecular scattering. The technique could be utilized for monitoring the stratospheric sulfuric acid aerosol layer during periods of background conditions. The polarization analysis method is discussed in light of simulation results and is applied to polarization lidar profiles observed during the ALBATROSS 1996 field measurement campaign.

Polarization Lidar: Correction of instrumental effects.

An algorithm for correcting instrumental effects in polarization lidar studies is discussed. Cross-talk between the perpendicular and parallel polarization channels and imperfect polarization of the transmitted laser beam are taken into account. On the basis of the Mueller formalism it is shown that - with certain assumptions - the combined effects of imperfect polarization of the transmitted laser pulse, non-ideal properties of transmitter and receiver optics and cross-talk between parallel and perpendicular polarization channels can be described by a single parameter, which is essentially the overall system depolarization.

Altitude range resolution of differential absorption lidar ozone profiles.

A method is described for the empirical determination of altitude range resolutions of ozone profiles obtained by differential absorption lidar (DIAL) analysis. The algorithm is independent of the implementation of the DIAL analysis, in particular of the type and order of the vertical smoothing filter applied. An interpretation of three definitions of altitude range resolution is given on the basis of simulations carried out with the Jet Propulsion Laboratory ozone DIAL analysis program, SO3ANL. These definitions yield altitude range resolutions that differ by as much as a factor of 2. It is shown that the altitude resolution calculated by SO3ANL, and reported with all Jet Propulsion Laboratory lidar ozone profiles, corresponds closely to the full width at half-maximum of a retrieved ozone profile if an impulse function is used as the input ozone profile.

Ray-tracing formulas for refraction and internal reflection in uniaxial crystals.

Formulas for the calculation of the direction cosines of refracted and internally reflected rays in anisotropic uniaxial crystals are presented. The method is based on a transformation to a nonorthonormal coordinate system in which the normal surface associated with the extraordinary ray is of spherical shape. A numerical example for the case of refraction and internal reflection in calcite is given.