Implementation of physical theory of diffraction for radar cross section calculations
Author(s)
Advisor
Altıntaş, AyhanDate
2002Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Abstract
A computer program which uses the Physical Theory of Diffraction (PTD)
method to calculate the Radar Cross Section (RCS) of perfectly conducting targets
with arbitrary shape is developed. Given an arbitrary surface, it is first
meshed using planar triangles. The area of each triangle is restricted to be smaller
than 0.005λ
2
in order to obtain a good approximation to the actual surface. After
meshing, Physical Optics (PO) surface integral is numerically evaluated over
the whole surface. If the surface has edges or wedges, diffractions originating
from these edges play a significant role in the overall scattered field. This part
of the diffracted field is calculated using PTD-EEC method. Calculation of the
edge currents is made possible by canonically modelling the arbitrary-shaped
edge. If the surface of the scatterer has thin wires attached to it, then the thin
wire scattering formulation in the literature is applied. Expressions for scattering
mechanism on a straight wire are based on diffraction, attachment, reflection
and launch. The results get sufficiently accurate especially for electrically large
bodies.
Keywords
Physical Theory of Diffraction (PTD)Triangular Surface Meshing
Physical Optics (PO)
Physical Theory of Diffraction-Equivalent Edge Currents (PTD-EEC)
Radar Cross Section
Scattering by Thin Wires