Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2019, Vol. 16, No. 1, pp. 72-79
Unnormalized moments in the problem of identifying scattering particles by cross sections
G.P. Arumov
1 , A.V. Bukharin
1 1 Space Research Institute RAS, Moscow, Russia
Accepted: 07.12.2018
DOI: 10.21046/2070-7401-2019-16-1-72-79
It is proposed to use unnormalized moments up to the fourth order as the statistical code of the aerosol source. The unnormalized moment of the first order is the transmission of the perforated screen and can be found from the total cross section of the particles in the image. The second-order unnormalized moment can be found from digital images and from the angular size of the scattering halo propagating in the beam. Unnormalized moments of higher orders can be measured by digital images and using 3d screens. The ratio of unnormalized moments of the second and first order gives the equivalent cross section of the particles. The number of sections is determined by the ratio of the square of the unnormalized moment of the first order to the unnormalized moment of the second order. It makes possible to simulate an equivalent medium for which the parameters of attenuation and lateral distortion of the beam are the same as those of the medium under study. The use of the developed method for the Poisson distributions, the Gamma distribution and the normal distribution leads to the fact that these distributions have properties similar in their parameters to monodisperse sections. On the example of a uniform distribution, a weak dependence of the equivalent cross section on the width of the distribution function of particle images over cross sections is shown. Using a statistical code allows to simulate the angular size of the beam in a scattering medium. The prospect of creating a probing system that is configured to the specified optical and geometrical parameters of the scattering medium appears. This possibility will allow to increase the measurement accuracy of the basic parameters of the scattering medium (extinction and backscatter coefficients). The developed method can be used to simulate the distribution function of scattering particles over sections and transmission and backscatter coefficients. In addition, the statistical code can be used to identify the aerosol from specified sources.
Keywords: unnormalized moment, cross-section, nonspherical particles, perforated screen, scattering medium, 3d screen, statistical code
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