Accession Number : ADP006113

Title :   Experiment and Theory for Backscattering Enhancement and Imaging in Ramdom Media,

Corporate Author : WASHINGTON UNIV SEATTLE DEPT OF ELECTRICAL ENGINEERING

Personal Author(s) : Ishimaru, Akira ; Kuga, Yasuo

Report Date : MAY 1987

Pagination or Media Count : 10

Abstract : When a wave is incident on a dense distribution of discrete scatterers, turbulent media, or rough surfaces, and backscatter is enhanced under certain conditions giving a sharp peak in the backward direction. Experimentally and theoretically the angular width of the peak is related to the transport coefficient and that the enhancement is caused by the constructive interference of two waves traveling through the same particles in opposite directions. This phenomena is identified as the weak Anderson localization. The backscattering enhancement can occur from turbulence or rough surfaces which are caused by several mechanisms. A measure of the quality of the image transmission is expressed by the modulation transfer function (MTF). We show experimental and theoretical studies on MTF and speckle interferometry based on the fourth order and short-exposure MTF which can produce diffraction-limited images through random scatterers. (Author)

Descriptors :   *ELECTROMAGNETIC WAVE REFLECTIONS, *BACKSCATTERING, TURBULENCE, TRANSFER FUNCTIONS, TRANSPORT PROPERTIES, SPECULAR REFLECTION, SYMPOSIA.

Subject Categories : Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE