SUMIGSPLIT - Split-step depth migration for zero-offset data.
sumigsplit <infile >outfile vfile= [optional parameters]
Required Parameters:
nz= number of depth sapmles
dz= depth sampling interval
vfile= name of file containing velocities
Optional Parameters:
dt=from header(dt) or .004 time sampling interval
dx=from header(d2) or 1.0 midpoint sampling interval
ft=0.0 first time sample
fz= first depth sample
tmpdir= if non-empty, use the value as a directory path
prefix for storing temporary files; else if the
the CWP_TMPDIR environment variable is set use
its value for the path; else use tmpfile()
Notes:
The input velocity file \'vfile\' consists of C-style binary floats.
The structure of this file is vfile[iz][ix]. Note that this means that
the x-direction is the fastest direction instead of z-direction! Such a
structure is more convenient for the downward continuation type
migration algorithm than using z as fastest dimension as in other SU
programs.
Because most of the tools in the SU package (such as unif2, unisam2,
and makevel) produce output with the structure vfile[ix][iz], you will
need to transpose the velocity files created by these programs. You may
use the SU program \'transp\' in SU to transpose such files into the
required vfile[iz][ix] structure.
(In C v[iz][ix] denotes a v(x,z) array, whereas v[ix][iz]
denotes a v(z,x) array, the opposite of what Matlab and Fortran
programmers may expect.) ",
Credits: CWP Baoniu Han, July 21th, 1997
Reference:
Stoffa, P. L. and Fokkema, J. T. and Freire, R. M. and Kessinger, W. P.,
1990, Split-step Fourier migration, Geophysics, 55, 410-421.
Trace header fields accessed: ns, dt, delrt, d2
Trace header fields modified: ns, dt, delrt