Verification the Umov effect on large irregular particles

Abstract

The paper presents a solution to the problem of light scattering by randomly oriented particles of irregular shape for particles with sizes of 100, 140, 170 and 200 microns for a wavelength of 0.532 microns for various refractive indices. The solution was constructed both within the framework of physical optics (for the backward scattering direction) and geometric optics (for scattering angles in the range from 0 to 180 degrees). The obtained solutions made it possible to construct a diagram of the dependence of the geometric albedo of a particle on the maximum degree of polarization to verify the Umov effect. It was found that when the imaginary part of the refractive index is less than 0.001, the Umov effect is performed with good accuracy. However, for the case when the imaginary part of the refractive index is greater than 0.001 and the specular component of the scattered radiation begins to dominate in the solution, the Umov effect is violated.