scholarly journals Algorithm for Solving the Light Scattering Problem for Arbitrary Shaped Ice Particles with Absorption

2020 ◽  
Vol 237 ◽  
pp. 08004
Author(s):  
Timofeev D.N. ◽  
Konoshonkin A.V. ◽  
Kustova N.V. ◽  
Borovoi A.G.
Keyword(s):  
Light Scattering ◽  
Scattering Problem ◽  
Scattering Matrix ◽  
Influence Effect ◽  
Ice Particles ◽  
Scattering Matrices ◽  
Research Show

The work presents the estimation of the absorption influence effect on the light scattering problem for atmospheric ice particles. The calculation of light scattering matrices was performed for two types of particles: the solid hexagonal columns and the arbitrary shaped particles. The range of the size for both types of particles varies from 10 μm to 1000 μm. The results of the research show an insignificant decrease of the value of the M11 element of the light scattering matrix for small-sized particles for all chosen wavelengths (0.355 μm, 0.532 μm, 1.064 μm и 1.6 μm), and a significant decrease for big-sized particles for a 1.6 μm wavelength.

scholarly journals Light Scattering by Particles with Arbitrary Shape in the Vicinity of the Backward Scattering Direction within Geometrical Optics Approximation

2020 ◽  
Vol 237 ◽  
pp. 08012
Author(s):  
Victor Shishko ◽  
Alexander Konoshonkin ◽  
Natalia Kustova ◽  
Anatoli Borovoi ◽  
Dmitry Timofeev
Keyword(s):  
Experimental Data ◽  
Refractive Index ◽  
Light Scattering ◽  
Arbitrary Shape ◽  
Specular Reflection ◽  
Scattering Problem ◽  
Geometrical Optics ◽  
Optical Characteristics ◽  
Ice Particles ◽  
Scattering Light

The work presents the solution for the light scattering problem by arbitrarily-shaped particles in the vicinity of the backward scattering direction. The solution was obtained within the framework of the geometrical optics approximation. The refractive index was equal to 1.3116. It was shown that the general contribution of scattering light for arbitrarily-shaped particles in the vicinity of the backscattering direction consists of the specular reflection of the particles and two types of non-specular optical beams. It is shown that the optical characteristics of the ice particles with arbitrary shapes correspond to experimental data.

scholarly journals Using the Physical Optics Approximation for Estimating the Light Scattering Properties of Large Dust Particles for Lidar Applications

2020 ◽  
Vol 237 ◽  
pp. 08025
Author(s):  
Alexander Konoshonkin ◽  
Natalia Kustova ◽  
Anatoli Borovoi ◽  
Alexandra Tsekeri ◽  
Josef Gasteiger
Keyword(s):  
Light Scattering ◽  
Extinction Coefficient ◽  
Scattering Problem ◽  
Power Laws ◽  
Scattering Matrix ◽  
Dust Particles ◽  
Physical Optics ◽  
Depolarization Ratio ◽  
Physical Optics Approximation ◽  
Dda Method

The physical optics approximation was used to solve the light scattering problem of large dust particles with irregular shape. The comparison between the physical optics approximation and the DDA method was made for particles with volume-equivalent size parameters of 44.21. A full light scattering matrix (Mueller matrix) was calculated for particles with volume-equivalent size parameters from 44 up to 220 for two wavelengths: 0.532 and 1.064 μm. The dependences of the lidar and depolarization ratio, and extinction coefficient on the number of spatial orientations of the particle were obtained. It was shown that the elements of the light backscattering matrix obey power laws.

scholarly journals An experimental study on light scattering matrices for Chinese loess dust with different particle size distributions

2020 ◽  
Vol 13 (8) ◽  
pp. 4097-4109
Author(s):  
Jia Liu ◽  
Qixing Zhang ◽  
Yinuo Huo ◽  
Jinjun Wang ◽  
Yongming Zhang
Keyword(s):  
Particle Size ◽  
Refractive Index ◽  
Light Scattering ◽  
Scattering Matrix ◽  
Dust Aerosol ◽  
Dust Particles ◽  
Size Distributions ◽  
Chinese Loess ◽  
Two Samples ◽  
Scattering Matrices

Abstract. Mineral dust suspended in the atmosphere has significant effects on radiative balance and climate change. The Chinese Loess Plateau (CLP) is generally considered one of the main sources of Asian dust aerosol. After being lifted by wind, dust particles with various size distributions can be transported over different distances. In this study, an original loess sample was collected from Luochuan, which is centrally located on the CLP, and two samples with different size distributions were obtained afterwards. “Pristine loess” was used to represent dust that only affects source regions, part of pristine loess was milled to finer “milled loess” that can be transported over long distances. Light scattering matrices for these two samples were measured at 532 nm wavelength from 5 to 175∘ angles. Particle size distribution, refractive index, chemical component, and microscopic appearance were also characterized for auxiliary analyses. Experimental results showed that there are obvious discrepancies in angular behaviors of matrix elements for pristine loess and milled loess, and these discrepancies are different from those for other kinds of dust with distinct size distributions. Given that the effective radii of these two loess samples differ by more than 20 times, it is reasonable to conclude that the difference in size distributions plays a major role in leading to different matrices, while differences in refractive index and microstructure have relatively small contributions. Qualitative analyses of numerical simulation results of irregular particles also validate this conclusion. Gaussian spheres may be promising morphological models for simulating the scattering matrix of loess but need further quantitative verification. Finally, synthetic scattering matrices for both pristine loess and milled loess were constructed over 0–180∘, and the previous average scattering matrix for loess dust was updated. This study presents measurement results of Chinese loess dust and an updated average scattering matrix for loess, which are useful for validating existing models, developing more advanced models for optical simulations of loess dust, and helping to improve retrieval accuracy of dust aerosol properties over both source and downwind areas.

scholarly journals Anisotropic dielectric susceptibility matrix of anisotropic medium

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wanrong Gao
Keyword(s):  
Light Scattering ◽  
Anisotropic Medium ◽  
Polarized Light ◽  
Scattering Matrix ◽  
Dielectric Susceptibility ◽  
Anisotropic Dielectric ◽  
New Methods ◽  
Mueller Matrices ◽  
Anisotropic Structures ◽  
The Fourier Transform

AbstractIn this work, we introduce the concept of anisotropic dielectric susceptibility matrix of anisotropic medium for both nondepolarizing and depolarizing medium. The concept provides a new way of analyzing light scattering properties of anisotropic media illuminated by polarized light. The explicit expressions for the elements of the scattering matrix are given in terms of the elements of the Fourier transform of the anisotropic dielectric susceptibility matrix of the medium. Finally, expressions for the elements of the Jones matrix of a thin layer of a deterministic anisotropic medium and the elements of the Mueller matrix of a depolarizing medium are given. The results obtained in this work is helpful for deriving information about the correlated anisotropic structures in depolarizing media from measured Mueller matrices. The findings in this work may also well prove stimulating to researchers working on new methods for analyzing light scattering properties.

scholarly journals Memory Efficient Method for Electromagnetic Multi-Region Models Using Scattering Matrices

2018 ◽  
Vol 23 (4) ◽  
pp. 71 ◽  
Author(s):  
C. Custers ◽  
J. Jansen ◽  
E. Lomonova
Keyword(s):  
Electromagnetic Field ◽  
Boundary Conditions ◽  
Efficient Method ◽  
Maximum Size ◽  
Scattering Matrix ◽  
Matrix Approach ◽  
Matrix Formulation ◽  
Scattering Matrices ◽  
Memory Efficient

This paper describes the scattering matrix approach to obtain the solution to electromagnetic field quantities in harmonic multi-layer models. Using this approach, the boundary conditions are solved in such way that the maximum size of any matrix used during the computations is independent of the number of regions defined in the problem. As a result, the method is more memory efficient than classical methods used to solve the boundary conditions. Because electromagnetic sources can be located inside the regions of a configuration, the scattering matrix formulation is developed to incorporate these sources into the solving process. The method is applied to a 3D electromagnetic configuration for verification.

Application of the Solution of the Inverse Light Scattering Problem for Characterization of Mononuclear Cells

2009 ◽  
Vol 4 (2) ◽  
pp. 61-68
Author(s):  
Dmitriy Strokotov ◽  
Yuriy Pichugin ◽  
Maxim Yurkin ◽  
Mariya Gridina ◽  
Oleg Serov ◽  
...  
Keyword(s):  
Stem Cells ◽  
Light Scattering ◽  
Mononuclear Cells ◽  
Human Lymphocytes ◽  
Scattering Problem ◽  
Refractive Indices ◽  
Single Particles ◽  
Differentiation Status

In this manuscript we propose two methods to solve inverse light scattering problem for single particles, which can be described as a coated sphere. The efficiency of the methods is illustrated by characterization of lymphocytes and stem cells using light scattering patterns obtained with scanning flow cytometer. Both methods, spectral and global optimization, were used to obtain diameters and refractive indices of the cytoplasm and the nucleus of mice embryo stem cells and human lymphocytes. These results agree with data obtained from other studies. Determination of these parameters is important for diagnostics of pathological states of lymphocytes and differentiation status of embryo stem cells. Moreover, methods described in this manuscript are applicable to all mononuclear cells. We also considered limitations of these methods and their possible improvements.

scholarly journals Intercomparison study and optical asphericity measurements of small ice particles in the CERN CLOUD experiment

2017 ◽  
Vol 10 (9) ◽  
pp. 3231-3248 ◽  
Author(s):  
Leonid Nichman ◽  
Emma Järvinen ◽  
James Dorsey ◽  
Paul Connolly ◽  
Jonathan Duplissy ◽  
...  
Keyword(s):  
Light Scattering ◽  
Single Particle ◽  
Optical Measurements ◽  
Optical Observations ◽  
Atmospheric Measurements ◽  
Optical Probes ◽  
Cloud Particle ◽  
Ice Particles ◽  
Cloud Particles ◽  
Ice Fraction

Abstract. Optical probes are frequently used for the detection of microphysical cloud particle properties such as liquid and ice phase, size and morphology. These properties can eventually influence the angular light scattering properties of cirrus clouds as well as the growth and accretion mechanisms of single cloud particles. In this study we compare four commonly used optical probes to examine their response to small cloud particles of different phase and asphericity. Cloud simulation experiments were conducted at the Cosmics Leaving OUtdoor Droplets (CLOUD) chamber at European Organisation for Nuclear Research (CERN). The chamber was operated in a series of multi-step adiabatic expansions to produce growth and sublimation of ice particles at super- and subsaturated ice conditions and for initial temperatures of −30, −40 and −50 °C. The experiments were performed for ice cloud formation via homogeneous ice nucleation. We report the optical observations of small ice particles in deep convection and in situ cirrus simulations. Ice crystal asphericity deduced from measurements of spatially resolved single particle light scattering patterns by the Particle Phase Discriminator mark 2 (PPD-2K, Karlsruhe edition) were compared with Cloud and Aerosol Spectrometer with Polarisation (CASPOL) measurements and image roundness captured by the 3View Cloud Particle Imager (3V-CPI). Averaged path light scattering properties of the simulated ice clouds were measured using the Scattering Intensity Measurements for the Optical detectioN of icE (SIMONE) and single particle scattering properties were measured by the CASPOL. We show the ambiguity of several optical measurements in ice fraction determination of homogeneously frozen ice in the case where sublimating quasi-spherical ice particles are present. Moreover, most of the instruments have difficulties of producing reliable ice fraction if small aspherical ice particles are present, and all of the instruments cannot separate perfectly spherical ice particles from supercooled droplets. Correlation analysis of bulk averaged path depolarisation measurements and single particle measurements of these clouds showed higher R2 values at high concentrations and small diameters, but these results require further confirmation. We find that none of these instruments were able to determine unambiguously the phase of the small particles. These results have implications for the interpretation of atmospheric measurements and parametrisations for modelling, particularly for low particle number concentration clouds.

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