Earth-prints repository, logo   DSpace

About DSpace Software
|earth-prints home page | roma library | bologna library | catania library | milano library | napoli library | palermo library
Please use this identifier to cite or link to this item:

Authors: Settimi, A.*
Bianchi, S.*
Title: Ray theory formulation and ray tracing method. Application in ionospheric propagation
Title of journal: quaderni di geofisica
Series/Report no.: 121/ (2014)
Issue Date: 23-Oct-2014
Keywords: Phase and ray velocity
Refractive index surface equation
Ray surface equation
Phase memory concept
Canonical ray equations
Application of Hamilton's equations
Hamilton’s ray equations with spherical coordinates
Fermat’s principle
General ray theory for a time-varying medium
Ray tracing method
Abstract: This work will lead to ray theory and ray tracing formulation. To deal with this problem the theory of classical geometrical optics is presented, and applications to ionospheric propagation will be described. This provides useful theoretical basis for scientists involved in research on radio propagation in inhomogeneous anisotropic media, especially in a magneto-plasma. Application in high frequencies (HF) radio propagation, radio communication, over-the-horizon-radar (OTHR) coordinate registration and related homing techniques for direction finding of HF wave, all rely on ray tracing computational algorithm. In this theory the formulation of the canonical, or Hamiltonian, equations related to the ray, which allow calculating the wave direction of propagation in a continuous, inhomogeneous and anisotropic medium with minor gradient, will be dealt. At least six Hamilton’s equations will be written both in Cartesian and spherical coordinates in the simplest way. These will be achieved by introducing the refractive surface index equations and the ray surface equations in an appropriate free-dimensional space. By the combination of these equations even the Fermat’s principle will be derived to give more generality to the formulation of ray theory. It will be shown that the canonical equations are dependent on a constant quantity H and the Cartesian coordinates and components of wave vector along the ray path. These quantities respectively indicated as ri(τ), pi(τ) are dependent on the parameter τ, that must increase monotonically along the path. Effectively, the procedure described above is the ray tracing formulation. In ray tracing computational techniques, the most convenient Hamiltonian describing the medium can be adopted, and the simplest way to choose properly H will be discussed. Finally, a system of equations, which can be numerically solved, is generated.
Appears in Collections:01.02.05. Wave propagation
01.02.04. Plasma Physics
05.05.99. General or miscellaneous
05.06.99. General or miscellaneous
05.01.05. Algorithms and implementation
Papers Published / Papers in press

Files in This Item:

File Description SizeFormatVisibility
ACCEPTED Settimi A. and Bianchi S. (2014), Quaderni di Geofisica 121, pp. 21.docAccepted Manuscript (Word)8.8 MBMicrosoft Wordonly authorized users View/Open
quaderno121.pdfMain article1.31 MBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Share this record




Stumble it!



Valid XHTML 1.0! ICT Support, development & maintenance are provided by CINECA. Powered on DSpace Software. CINECA