论文信息 - RCS computations with PO/PTD for conducting and impedance objects modeled as large flat plates

RCS computations with PO/PTD for conducting and impedance objects modeled as large flat plates

RCS COMPUTATIONS WITH PO/PTD FOR CONDUCTING AND IMPEDANCE OBJECTS MODELED AS LARGE FLAT PLATES N. A. Albayrak M.S. in Electrical and Electronics Engineering Supervisor: Prof. Dr. Ayhan Altintas July 2005 Calculation of Radar Cross Section (RCS) of arbitrary bodies using Physical Optics (PO) Theory and Physical Theory of Diffraction (PTD)is considered. For bodies with impedance surface boundary condition, only PO is used. Analytical approach to PO integral is used to achieve faster computations. A computer program has been developed in Fortran in order to calculate the Radar Cross Section (RCS). Arbitrary shape is modeled as triangular facets of any area by the help of graphical tools. Given the triangular meshed model of an arbitrary body, Physical Optics(PO) surface integral is numerically evaluated over the whole surface. There is no limitation on the size of the triangles, as soon as the total surface does not retire from the original one. Shadowing algorithm has been used in order to have more accurate solutions. Additionally, flash points of PO are visualized over the surface of targets, hence local nature of high-frequency phenomena is proved. Induced surface currents, edge currents and RCS have been calculated for some basic shapes and the fuel tank model of F-16 airplanes. Induced surface

N. Albayrak | N. A. Albayrak

[1] R. F. Millar. An Approximate Theory of the Diffraction of an Electromagnetic Wave by an Aperture in a Plane Screen , 1956 .

[2] John F. Shaeffer,et al. Radar Cross Section , 2004 .

[3] A. Michaeli. Equivalent edge currents for arbitrary aspects of observation , 1984 .

[4] R. Harrington. Time-Harmonic Electromagnetic Fields , 1961 .

[5] P. Pathak. Techniques for High-Frequency Problems , 1988 .

[6] K M Mitzner,et al. Incremental Length Diffraction Coefficients , 1974 .

[7] C. J. Ball. An introduction to the theory of diffraction , 1971 .

[8] R. Luebbers,et al. FDTD modeling of thin impedance sheets (radar cross section calculation) , 1992 .

[9] Tomas Akenine-Möller,et al. Fast, Minimum Storage Ray-Triangle Intersection , 1997, J. Graphics, GPU, & Game Tools.

[10] Corner diffraction coefficients for the quarter plane , 1991 .

[11] Derek A. McNamara,et al. Introduction to the Uniform Geometrical Theory of Diffraction , 1990 .

[12] P. Ufimtsev,et al. Method of Edge Waves in the Physical Theory of Diffraction , 1971 .

[13] Tomas Akenine-Möller,et al. A Fast Triangle-Triangle Intersection Test , 1997, J. Graphics, GPU, & Game Tools.

[14] A. Michaeli. Elimination of infinities in equivalent edge currents, Part II: Physical optics components , 1986 .

[15] J. Shaeffer. EM scattering from bodies of revolution with attached wires , 1980 .