3D high order finite difference modeling and migration program implemented on the Cray X-MP out-of-core version

This paper describes the development and testing of a vectorized, 3D out-of-core modeling/migration program with absorbing boundary conditions for the Cray X-MP supercomputers using a high order finite difference method. The program has several alternatives for the user to select: (1). modeling or migration. (2). fourth order or sixth order finite-difference. (3). with or without absorbing boundary conditions. In the program, density is assumed to be a constant. Velocity v(x,y,z) can vary with x,y,z. The velocity matrix should be provided by the user. The program is aimed at dealing with very large data sets. In order to efficiently process a large amount of data, 4 parallel input/output channels are used to transfer data between main memory and disks. The I/O is also asynchronous.