APPLICATION OF WAVE DIFFRACTION DATA

The application of diffraction tomography to cross-hole seismic data

Previously published equations for diffraction tomography do not solve the “two and one-half dimensional problem” (point source illumination of two-dimensional geology) if sources and receivers are confined to linear arrays. In spite of this lack of a formal solution, useful images can be formed by the application of twodimensional formulas to such problems. The estimation of difference fields....

Boundary diffraction wave integrals for diffraction modeling of external occulters.

An occulter is a large diffracting screen which may be flown in conjunction with a telescope to image extrasolar planets. The edge is shaped to minimize the diffracted light in a region beyond the occulter, and a telescope may be placed in this dark shadow to view an extrasolar system with the starlight removed. Errors in position, orientation, and shape of the occulter will diffract additional...

Diffraction properties of substrate guided- wave holograms

Substrate guided-wave (SGW) holograms are recorded by guiding the reference wave to the hologram using an optical substrate.1'2 As compared to conventional holographic recording systems, SGW systems are compact, portable, robust, and easy to align. Since the illuminating beam is encapsulated within the substrate and only the holographic image is diffracted, the hologram can be viewed close to t...

Edge diffraction of a convergent wave.

Closed-form solutions have been derived for the diffraction patterns at the focal plane of (1) a convergent wave of unit amplitude illuminating a segment of a circular aperture and (2) a convergent wave of Gaussian amplitude diffracted by an infinite edge. Photographs showing the main features of these edge transform patterns are presented together with computer-generated graphs.

Application of the finite difference method in seismic source and wave diffraction simulation