Object structure

Journal or Publication Title:

Բյուրականի աստղադիտարանի հաղորդումներ: Երևանի աստղադիտարանի բյուլետեն = Сообщения Бюраканской обсерватории. Бюллетень ереванской Астрономической обсерватории = Contributions from the Burakan observatory. Bulletin of the Erevan astronomical observatory

Date of publication:

2024

Volume:

71

Number:

2

ISSN:

2579-2276

Title:

Complete simplification of the solution of the diffuse reflection problem by the method of “decomposition of resultant field” (DRF)

Creator:

Pikichyan, H. V.

Subject:

Radiative transfer

Uncontrolled Keywords:

diffuse reflection problem ; redistribution of radiation by frequencies ; Ambartsumian’snonlinear functional equation ; eigenfunctions in radiative transfer ; decomposition of the resultingfield

Coverage:

275-288

Abstract:

The classical diffuse reflection problem (DRP) of radiation from a plane-parallel semi-infinite medium under isotropic scattering in the case of the general law r (x, x′) of radiation redistribution by frequencies in the elementary act of scattering is considered. It is shown that the solution of the DRP ρ ( x, μ;x ′ , μ ′) , which depends on four independent variables, with the help of author’s recently developed method of ”decomposition of the resultant field-DRF” it is possible to express explicitly through auxiliary functions Gi (z) , Qi (x) that depend on only one independent variable. A significant difference between this DRF method and the widely used traditional approach of ”decomposition of a single act - DSA” of scattering is that it no longer requires any decomposition or a special representation of the characteristics of a single act of scattering (in the case under consideration, the function of redistribution of radiation by frequencies - r (x, x′)) . In DRF, the resulting field of multiply scattered radiation itself is searched directly in the decomposed form. It is obvious that after each successive single act of scattering, the resulting radiation field in the medium becomes more and more smoother, so that with the same required accuracy, its decomposition will contain fewer terms than the decomposition of the characteristic of a single act of scattering. This circumstance makes the DRF method especially effective in relation to the DSA approach in cases where the latter requires taking into account a large number of terms of the decomposition of the frequency redistribution function r (x, x′) . Explicit analytical expressions of the two-way relationship are also obtained between the desired values of the traditional and the methods proposed by the author.

Type:

Electronic journal

Format:

pdf

Identifier:

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General note:

Communications of the Byurakan Astrophysical Observatory (ComBAO) is a peer-reviewed scientific journal, which publishes research in observational and theoretical astronomy/astrophysics and presents recent advances in these fields. It is being published by the NAS RA V. Ambartsumian Byurakan Astrophysical Observatory (BAO) in English in electronic form. The journal publishes original papers, review papers, brief reports, book reviews, special communications, observational and theoretical results in various fields of astronomy and related sciences, and some editorial notes, including anniversaries and obituaries. Under the heading “Legacy”, the renewed magazine will republish some old articles of high value in English. The heading “Guest articles” will bring to the attention of readers the articles of researchers who are not employees of BAO. ComBAO was founded in 1946 and regularly published in 1946-1990. However, the publication was interrupted because of the economic situation after the disintegration of the Soviet Union in 1991.

Location of original object:

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