|ACCESSION NO.:  AAG9401252
|        TITLE:  ELECTROMAGNETIC SCATTERING FROM POLYNOMIAL SURFACES
|                (PHYSICAL OPTICS)
|       AUTHOR:  EBIHARA, WATARU
|       DEGREE:  PH.D.
|         YEAR:  1993
|  INSTITUTION:  THE OHIO STATE UNIVERSITY; 0168
|      ADVISER:  Adviser: LEON PETERS, JR.
|       SOURCE:  DAI, VOL. 54-08B, Page 4310, 00185 Pages
|  DESCRIPTORS:  ENGINEERING, ELECTRONICS AND ELECTRICAL; PHYSICS, OPTICS;
|                COMPUTER SCIENCE
|
|     ABSTRACT:  The scattered field from a perfectly conducting surface
|                defined by polynomial functions is investigated. A far-zone
|                solution based on the high-frequency method of Physical
|                Optics (PO) is the primary area of emphasis. Polynomials fit
|                a wide class of smooth surfaces, and this study has
|                potential application in the computer-aided design of
|                general scatters to meet various electromagnetic
|                specifications.
|
|                The computation of the PO solution is discussed with the
|                goal of developing efficient and accurate solutions. Special
|                functions, including the Fresnel integral and the incomplete
|                Airy function, can be used. Their use can result in faster
|                computation times over direct numerical integration. The use
|                of higher-order polynomials help smooth discontinuities when
|                interpolating a surface, and they provide an alternative to
|                linear "faceting".
|
|                The use of special functions for the PO solution can
|                compensate shortcomings of the high-frequency asymptotic PO
|                solution and the first-order GTD edge-diffraction solution.
|                Uniform transition functions are developed. Transition
|                functions based on PO are introduced into the diffraction
|                coefficients and the specular reflection contributions.
|                Transition functions also provide a way to visualize the
|                workings of the PO solution, and can be used to accelerate
|                computation.