Ludmila I. Chaikovskaya

Approximate theory of linearly polarized light propagation through a scattering medium

Abstract This work continues developing the analytical theory of polarized light transfer through scattering media and simplification of the Greens matrix of the problem with splitting the equations for Greens matrix elements started in our previous paper (Zege EP, Chaikovskaya LT. JQSRT 1996;55:19–31). The specific problem is the propagation of linearly polarized light, which is governed by the central block of the Greens matrix with elements (2,2), (2,3), (3,2), (3,3). The small parameter of the propagation problem is a value, which characterizes the rotation of the polarization plane in a near-forward scattering event. For a macroscopically isotropic medium with large scattering particles this value is always small. A new set of transfer equations for linearly polarized light propogation and scattering is given, splitting of this equation having been achieved. The more forward elongated the medium phase function is the more accurate the solution to the problem. An effective iteration procedure to solve the original set of equations is suggested. It is shown that the linearly polarized light transfer problem reduces to a scalar problem and can be solved analytically for small-angle forward propagation and near-backward scattering.

Polarization of multiply scattered lidar return from clouds and ocean water

An analytical solution to polarized lidar return, including multiple scattering from stratified media with large scatters, is developed and discussed.

Lidar returns from multiply scattering media in multiple-field-of-view and CCD lidars with polarization devices: comparison of semi-analytical solution and Monte Carlo data

Quite recently, a semi-analytical approach to the sounding of multiply scattering media (clouds, seawaters) using multiple-field-of-view and CCD lidars with polarization devices was developed. The angular distributions of polarized components of the lidar returns from multiply scattering media computed on the basis of this theory using the small-angle approximation are presented and discussed. The semi-analytical nature of the solution makes the computation procedure faster. The obtained data are compared with results provided by the most advanced Monte Carlo algorithms for simulation of modern lidar performance. The good agreement between data provided by the semi-analytical approach and Monte Carlo computations assures one that these approaches can serve as a reliable theoretical base for interpretation and inversion of cloud lidar sounding data obtained with polarized lidars, including polarized multiple-field-of-view and CCD lidars.

Backscattering patterns in the polarized lidar sounding of strongly scattering media

Theory of polarized lidar sounding of multiply scattering media with highly anisotropic phase functions which describes angular patterns with representative azimuth structure of the backscattered signal observed through the polarizer and analyzer is proposed. Such patterns were visualized by other investigators in the plane perpendicular to the receiver optical axis in experiments performed on the base of mono-static polarized lidar systems. Previously obtained approximate equations of the vector theory along with generalized approximations earlier developed in the scalar theory form the basis for our theory. Solution expressed through multidimensional integrals which determine return polarization parameters is presented and explained. It accounts for formation of a signal as a process consisting of single scattering events into the backward region and propagation and small-angle scattering into near-forward directions before and after the back-scattering events. The developed solution gives the return angular pattern for any initial and received states of polarization and includes the multiple scattering. Half-analytical fast techniques that have been developed on the base of the obtained solution are used to simulate the near-backscattering patterns. Computed examples of the patterns for the case of scattering in seawaters are shown and discussed.

Combined ground-based and satellite remote sensing of atmospheric aerosol and Earth surface in the Antarctic

The paper presents lecture materials given at the Nineteenth International Conference and School on Quantum Electronics “Laser Physics and Applications” (19th ICSQE) in 2016, Sozopol, Bulgaria and contains the results of the 10-year research of Belarusian Antarctic expeditions to study the atmospheric aerosol and Earth surface in Antarctica. The works focus on the studying variability and trends of aerosol, cloud and snow characteristics in the Antarctic and the links of these processes with the long range transport of atmospheric pollutants and climate changes.