A hybrid (finite difference-surface Green´s function) method for computing transmission losses in an inhomogeneous atmosphere over irregular terrain

Author

Marcus, Sherman W.

Author_Institution

RAFAEL, Haifa, Israel

Volume

40

Issue

12

fYear

1992

fDate

12/1/1992 12:00:00 AM

Firstpage

1451

Lastpage

1458

Abstract

A standard parabolic equation (SPE) is used to approximate the Helmholtz equation for electromagnetic propagation in an inhomogeneous atmosphere. An implicit finite difference (IFD) scheme to solve the SPE is applied between the irregularly shaped ground and an altitude z =z_h, below which all inhomogeneities of the medium are assumed localized. The boundary condition at z=z _h is obtained by matching the IFD solution to a surface Green´s function (SGF) solution within the uniform region above z =z_h. For ground slopes above about 1°, the IFD implementation of the impedance boundary condition at the ground is shown to maintain the validity of the approximation only for vertically polarized waves. Predictions using this hybrid finite difference (FD)-SGF method agree well with results obtained using other computational methods

Keywords

Green´s function methods; finite difference methods; radiowave propagation; tropospheric electromagnetic wave propagation; Helmholtz equation; boundary condition; electromagnetic propagation; finite difference-surface Green´s function; hybrid method; impedance boundary condition; inhomogeneous atmosphere; irregular terrain; standard parabolic equation; transmission losses; troposphere; vertically polarized waves; Acoustic propagation; Atmosphere; Boundary conditions; Difference equations; Differential equations; Electromagnetic propagation; Finite difference methods; Green´s function methods; Propagation losses; Surface impedance;

fLanguage

English

Journal_Title

Antennas and Propagation, IEEE Transactions on

Publisher

ieee

ISSN

0018-926X

Type

jour

DOI

10.1109/8.204735

Filename

204735