Accession Number : ADA297694

Title :   Radiowave Propagation Over an Irregular Terrain Using the Parabolic Equation Method in a Curvilinear Coordinate System.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Lee, Joo-Kiong

PDF Url : ADA297694

Report Date : MAR 1995

Pagination or Media Count : 101

Abstract : The problem of radiowave propagation over irregular terrain is solved by using the standard parabolic equation method. The ground is characterized by an impedance boundary condition and a height profile. A tropospheric boundary condition is used to truncate the computational domain. This thesis uses a novel approach of casting all the equations in a curvilinear coordinate system. The coordinate system is generated in a simple manner using the ground profile data. The equations are solved by the finite difference method using the Crank-Nicolson scheme. Different numerical values for various important parameters (e.g., step size, location of tropospheric boundary, the region above the tropospheric boundary, etc.) were used, and their effect on the accuracy and computing time are discussed. Validation of the numerical results with exact and/or experimental results are presented for different terrain profiles. Both perfectly electric conducting (PEC) and lossy impedance surfaces are considered. (KAR) P. 2

Descriptors :   *ELECTROMAGNETIC WAVE PROPAGATION, *TERRAIN, *PARTIAL DIFFERENTIAL EQUATIONS, *RADIO WAVES, LINEAR SYSTEMS, GROUND LEVEL, COMPUTATIONS, SIZES(DIMENSIONS), VALIDATION, NUMERICAL ANALYSIS, SURFACE ROUGHNESS, ACCURACY, THESES, SURFACES, BOUNDARIES, FINITE DIFFERENCE THEORY, PROFILES, COORDINATES, PARABOLAS, STANDARDIZATION, LOSSES, IMPEDANCE, TROPOSPHERE, HEIGHT, TRUNCATION, CURVES(GEOMETRY).

Subject Categories : Geology, Geochemistry and Mineralogy
      Numerical Mathematics
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE