Radio wave propagation in the presence of a coastline

Abstract

[1] In this paper the effect of a coastline on radio wave propagation is analyzed. The coastline consists of a shoreline or land/sea transition in the presence of a cliff or bluff. The problem of diffraction from the transition, when excited by a small dipole, is first addressed. By application of a perturbation technique the effects of a gradual, as opposed to an abrupt transition on the radio wave are discussed. For the case of both source and observation near the surface it is shown that the received fields are independent of the gradient of the transition and that the effects of the land/sea transition on the total fields are dominant, even distant from the transition. This is a very important and counterintuitive result which has not been reported previously. A UTD solution for an impedance wedge and plane wave excitation is then applied, in order to analyze the combined effect of the land/sea transition and a cliff or bluff on the total received fields. Results are shown for the case of an observation platform (such as an aerial vehicle) flying low over the sea and then up and over the bluff.

Scattering theory of waves by a perfectly conducting half‐screen between two different media

“…The interaction problem of waves by a half‐plane, located on a junction between two different media, is an important problem in wave propagation and scattering at land‐sea transition and remote sensing applications of land, sea surfaces, and forests . This problem was first studied by Clemmow for radio wave propagation over earth in 1953 .…”

Compact Reconfigurable High-Frequency Ultrahigh Frequency (HG-UHF) Antenna

“…'Y-Before proceeding wfth the development of the FMM representation of the total field (Green's function), it is"worth noting the convergence properties of the integrals in (23). The two exponential decaying factors (a,/?)…”

“…Thus, while simple to implement, these models lack the desired accuracy and generality. In recent years significant efforts have been devoted towards the development of physicsbased electromagnetic (EM) models, which apply analytic and numeric techniques for channel modeling [16,17,18,19,2,20,21,22,23,24]. These models allow for characterization of the communications channel to a high degree of fidelity, and are" able to simulate varied propagation environments, including the polarimetric aspects of the channel.…”