Diffraction of Radio Waves in a Stratified Troposphere

Abstract

The problem of diffraction around a smooth, finitely conducting earth is reexamined with the objective of obtaining an exact solution for the case of an exponential profile of refractivity. The methods employed are largely conventional. However, care is taken to avoid approximations of doubt· ful accuracy, and the solution is illustrated by numerical computations. It is shown that the method of using an effective earth radius and assuming a homogeneous medium is generally sound.

Propagation in a Superrefractive Troposphere With a Nontrapping Surface Layer

“…The asymptotic solutions of (2) may he written g1(z)= t/l(z)hi(,), g2 (z) = t/J(z) hz(Q, When {3 = 0, this reduces to the profile considered earlier (Gerks & Anderson, 1966). The surface anom-where aly can be adjusted by the choice of {3.…”

“…curacy. The first phase is illustrated in an earlier paper by Gerks and Anderson (1966). In fact, the differential equation and the form of the solution remained unchanged.…”

“…The principal solution is chosen so that it satisfies the radiation condition as z~ oo. As shown in the earlier paper (Gerks and Anderson, 1966), the solution involves determining modal values of the complex paramete~ Zt-…”

Internal Guiding of Microwaves by an Elevated Tropospheric Layer

“…Although turbulence, no doubt, plays a major role, there is also evidence that stable layer formations will provide an excellent and efficient guiding mechanism. Various vertical profiles of the refractive index have been considered [Pekeris, 1946;Langer, 1951;Brekhovskikh, 1960;Wait, 1962;Fock, 1965;Gerks and Anderson, 1966]. It does seem surprising, however, that little attention has been given to the internal guiding properties of a single elevated layer.…”

Propagation in a Superrefractive Troposphere with a Trapping Surface Layer

“…This paper is an extension of a study begun several years ago [Gerks and Anderson, 1966]. In this study, certain approximations, such as replacing an exponential profile of refractivity with a linear profile, were avoided, and advantage was taken of modern computers to obtain results of improved accuracy.…”