TY - JOUR
AB - We consider light scattering from a new type of model particle whose shape is represented in the form of a generalized ellipsoid having N foci, where N is greater than two. Such particles can be convex as well as concave. We use the geometrical optics approximation to study the light scattering from 3-foci particles. Non-zero elements of the scattering matrix are calculated for ensembles of randomly oriented independent transparent particles, m = n + i0. Several internal reflection orders are considered separately. It was found that the transmission-transmission (TT) and transmission-reflectance-transmission (TRT) components dominate in the formation of intensity of scattered light at large and small phase angles, respectively. We found a significant role of the total internal reflections of the TRT in the middle portion of the phase angle range. The main factors in the formation of positive linear polarization are the R and TRT component. The TT component is responsible for the formation of negative polarization branch at large phase angles.
AU - Stankevich, Dmitriy
AU - Hradyska, Larissa
AU - Shkuratov, Yuriy
AU - Grynko, Yevgen
AU - Videen, Gorden
AU - Förstner, Jens
ID - 8872
JF - Journal of Quantitative Spectroscopy and Radiative Transfer
KW - tet_topic_scattering
SN - 0022-4073
TI - Light scattering by 3-Foci convex and concave particles in the geometrical optics approximation
ER -
TY - JOUR
AB - The problem of light scattering by ice crystals of cirrus clouds is considered in the case of a hexagonal ice plate with different distributions over crystal orientations. The physical-optics approximation based on (E, M)-diffraction theory is compared with two exact numerical methods: the finite difference time domain (FDTD) and the discontinuous Galerkin time domain (DGTD) in order to estimate its accuracy and limits of applicability. It is shown that the accuracy of the physical-optics approximation is estimated as 95% for the averaged backscattering Mueller matrix for particles with size parameter more than 120. Furthermore, the simple expression that allows one to estimate the minimal number of particle orientations required for appropriate spatial averaging has been derived.
AU - Konoshonkin, Alexander
AU - Borovoi, Anatoli
AU - Kustova, Natalia
AU - Okamoto, Hajime
AU - Ishimoto, Hiroshi
AU - Grynko, Yevgen
AU - Förstner, Jens
ID - 3834
JF - Journal of Quantitative Spectroscopy and Radiative Transfer
KW - tet_topic_scattering
SN - 0022-4073
TI - Light scattering by ice crystals of cirrus clouds: From exact numerical methods to physical-optics approximation
VL - 195
ER -
TY - JOUR
AB - The physical optics approximations are derived from the Maxwell equations. The scattered field equations by Kirchhoff, Stratton-Chu, Kottler and Franz are compared and discussed. It is shown that in the case of faceted particles, these equations reduce to a sum of the diffraction integrals, where every diffraction integral is associated with one plane–parallel optical beam leaving a particle facet. In the far zone, these diffraction integrals correspond to the Fraunhofer diffraction patterns. The paper discusses the E-, M- and (E, M)-diffraction theories as applied to ice crystals of cirrus clouds. The comparison to the exact solution obtained by the discontinuous Galerkin time domain method shows that the Kirchhoff diffraction theory is preferable.
AU - Konoshonkin, Alexander V.
AU - Kustova, Natalia V.
AU - Borovoi, Anatoli G.
AU - Grynko, Yevgen
AU - Förstner, Jens
ID - 3849
JF - Journal of Quantitative Spectroscopy and Radiative Transfer
KW - tet_topic_scattering
SN - 0022-4073
TI - Light scattering by ice crystals of cirrus clouds: comparison of the physical optics methods
VL - 182
ER -