Accession Number : AD0421464

Title :   ON SCATTERING AND REFLECTION BY ELLIPTICALLY STRIATED SURFACES,

Corporate Author : SYLVANIA ELECTRONIC SYSTEMS-WEST MOUNTAIN VIEW CALIF ELECTRONIC DEFENSE LABS

Personal Author(s) : Burke,J. E. ; Twersky,V.

Report Date : 22 OCT 1962

Pagination or Media Count : 82

Abstract : The general results given previously, for scattering and reflection by rough surfaces, are applied to elliptically striated surfaces, i.e., to random distributions of semi-elliptic protuberances on a ground plane. Closed forms for the power reflection coefficient R, for the phase of the coherently reflected wave, and for the differential scattering cross section sigma, are obtained by substituting appropriate approximations for the scattering amplitude f of an isolated perfectly conducting semi-elliptic protuberance. For low frequencies, the real and imaginary parts of the f's required in R and sigma are given explicitly to the eighth and sixth power of the frequency, respectively. At high frequencies an approximation for the isolated scattering amplitude is used which includes the geometrically reflected term and the shadow-forming diffracted term; the fields for the distribution show both multiple geometricalreflection effects and multiple-shadowing effects. Illustrative numerical examples are given for semi-ellipses ranging from perpendicular strips, through semi-circles, to the limiting case of flat strips. We consider both horizontal and vertical polarization, and all angles of incidence. (Author)

Descriptors :   (*SURFACES, SCATTERING), (*REFLECTION, SURFACES), COHERENT SCATTERING, DISTRIBUTION, POWER, LOW FREQUENCY, HIGH FREQUENCY, DIFFRACTION, POLARIZATION, GEOMETRY, ANTENNAS, CYLINDRICAL BODIES

Distribution Statement : APPROVED FOR PUBLIC RELEASE