Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

3D migration on the Cray X-MP

Thesis/Dissertation ·
OSTI ID:7204004
Implementation on the Cray X-MP of 3D migration algorithms derived from the Phase Shift method is presented. Due to the enormous amount of data to process, 3D migration algorithms are very demanding in I/O resources and CPU time. A package of subroutines, called Slice-4, has been designed in order to offer an efficient scheme to store and retrieve data from disk to main memory. Efficiency is achieved through an appropriate storage scheme, asynchronism and parallelism in the data transfers. The implementation of the Phase Shift migration algorithm using Slice-4 is described. This algorithm assumes the absence of lateral variations in the velocity field and is thus not appropriate for the migration of complicated geological structures. A new algorithm, called the Phase Shift Plus Correction (PSPC) method is presented. In this algorithm, which takes into account lateral velocity variations, the migration is performed through a two steps process. In the first step, a downward extrapolation is performed using the Phase Shift algorithm and a constant velocity. In the second step, a correction term is introduced.
Research Organization:
Houston Univ., TX (USA)
OSTI ID:
7204004
Country of Publication:
United States
Language:
English

Similar Records

Vectorization of a thermal-hydraulics code on the CRAY X-MP
Conference · Wed Dec 31 23:00:00 EST 1986 · Trans. Am. Nucl. Soc.; (United States) · OSTI ID:6861218

Experience of implementing applicative parallelism on Cray X-MP
Conference · Sun May 01 00:00:00 EDT 1988 · OSTI ID:7184030

Efficient migration through complex water-bottom topography
Journal Article · Sun Feb 28 23:00:00 EST 1993 · Geophysics; (United States) · OSTI ID:6136597