Scattering of Waves by a Medium with Strong Fluctuations of Refractive Index

Abstract

The scattering of waves obeying the scalar wave equation is studied by a method which can be applied to large fluctuations of the refractive index. Besides the general theory, a detaile~ treatment of the scattering from a half-space and from a slab is given. The results can be applied to circum· stances under which the Born approximation fails. This situation seems to arise in connection with the electromagnetic scattering from wakes of supersonic reentry vehicles.

Ion Sampling from the Positive Column of dc Discharges in He–Ar Mixtures

“…While this may be a consequence of conversion to Ar2+ or Ar+,20 the absence of HeAr+ in the present studies and in recent afterglow measurements 21 suggest that HeAr+ may tend to be unstable. 22 For planewave propagation in a random continuum, the changes in mean-square amplitude and phase variations are derived due to the presence in the medium of a large spherical object arbitrary in density and refractive index, and positioned on the transmitter-to-receiver line-of-sight. The random continuum is taken as statistically homogeneous and isotropic in space with weak, large-scale refractive-index variations representable by a Gaussian autocorrelation function.…”

Wave Propagation in a One‐Dimensional Random Medium

“…Piero Bossonini (33) In order to find the limits of validity of the first renormalization solution, we shall find the conditions under which the corrections introduced by the subsequent renormalization can be neglected. Under these conditions, the first term of the renormalized series (22) is asymptotic to the exact solution (see Bassanini et al, 1967).…”

“…In 1963, Tatarskii and Gertsenshtein introduced a "renormalization" method which can be used in the case of scattering of scalar waves with strong fluctuations of the random refractive index. This method was subsequently applied by Bassanini, Cercignani, Sernagiotto, and Tironi (1967) to scattering of scalar waves by a half-space and a slab of turbulent plasma, and extended by Ryzhov, Tamoikin, and Tatarskii (1965) to the case of electromagnetic waves.…”

Field Fluctuations in a Random Continuum Containing a Spherical Object Inclusion

“…I 3-1S Propagation of waves in a continuum with strong refractive-index fluctuations, or in those cases where the field fluctuations are not small, is given separate treatment in the Ii tera ture. l [9][10][11][12][13][14][15][16][17][18][19][20][21][22] The present paper has as its objective the derivation of amplitude and phase variation experienced by a harmonic wave propagating in a randomly inhomogeneous medium and scattering from a spherical object embedded in that medium. Study of the expectation (or mean) value of a coherent wave scattered by a perfectly conducting sphere and by a general class of deterministic objects embedded in a random medium has been performed recently by Chen,23.24 who found that, in general, the expected wave field can be com-c. C. 1{NOttMAN puted from the corresponding deterministic scattering problem with the mean propagation constant replaced by an effective propagation constant.…”