Method of Spherical Phase Screens for Modeling the Propagation of Diverging Beams in Inhomogeneous Media

M E Gorbunov,A E Mamontov,O A Koval

doi:10.1134/s0001433820010041

Abstract

The phase-screen (split-step) method is widely used for modeling wave propagation in inhomogeneous media. The method of plane phase screens is best known. However, for modeling a 2D problem of radio occultation sounding of the Earth’s atmosphere, the method of cylindrical phase screen was developed many years ago. In this paper, we propose a further generalization of this method for the 3D problem on the basis of spherical phase screens. In the paraxial approximation, we derive the formula for the vacuum screen-to-screen propagator. We also infer the expression for the phase thickness of a thin layer of aisotropic random media. We describe a numerical implementation of this method and give numerical examples of its application for modeling a diverging laser beam propagating on a 25-km-long atmospheric path.

Highlights

The method of phase screens has been widely used for the numerical simulation of the wave propagation of various nature in inhomogeneous media, including the modeling of the optical radiation propagation in a turbulent atmosphere [1,2,3,4,5] and the decimeter waves propagation during radio occultation sounding of the atmosphere [6,7,8]
We developed a new modification of the phase-screen method, which provides a reduction in computational costs when modeling the propagation of diverging wave beams
We obtained the expression for the vacuum propagator describing the propagation from screen to screen

Summary

Introduction

The method of phase screens has been widely used for the numerical simulation of the wave propagation of various nature in inhomogeneous media, including the modeling of the optical (laser) radiation propagation in a turbulent atmosphere [1,2,3,4,5] and the decimeter waves propagation during radio occultation sounding of the atmosphere [6,7,8]. This method is referred to as split-step.

Vacuum propagator

Phase raid in a thin spherical layer

Numerical modeling method

Results

Conclusions