The accuracy of computing ionospheric radio-wave scintillation by the thin-phase-screen approximation

Abstract

In the calculation of the diffraction effects produced by a thick medium containing spatial irregularities in refractive index, a commonly-used approximate method is to represent the thick medium by a thin phase-changing screen. It is sometimes assumed that this gives a poor approximation when the medium is thick enough to produce appreciable amplitude fluctuations in the emergent wave. It is shown here that under practical ionospheric conditions the thin screen method still gives results in very good agreement with those obtained from a single-scattering calculation, even at gigahertz frequencies.