NAME
asig3d - calculation of seismic attributes due to reflec-
tion events averaged along the instantanteous dip and
azimuth directions determined from program semb3d.
SYNOPSIS
asig3d [ -Nfile_in ] [ -Ofile_out ] [ -IEfile_ienv ] [
-IPfile_iphase ] [ -IFfile_ifreq ] [ -IBWfile_ibw ] [
-REfile_renv ] [ -RPfile_rphase ] [ -RFfile_rfreq ] [
-RBWfile_rbw ] [ -RTfile_risetime ] [ -Cfile_carrier ] [
-Sfile_skewness ] [ -P0file_phase0 ] [ -P90file_phase90 ] [
-V ] [ -? ]
DESCRIPTION
asig3d reads in 3D dip and azimuth angle stack gathers gen-
erated from routine semb3d and at each point (t,x,y) outputs
the attribute corresponding to that angle whose semblance is
maximum.
asig3d gets all its parameters from command line arguments.
These arguments specify the input, output, spatial analysis
window, and dip discretization parameters. asig3d should not
be considered to be a stand alone program, but rather a
postprocessing program for routine semb3d.
-N file_in
Enter the input data set name or file immediately after
typing -N. This input file should include the complete
path name if the file resides in a different directory.
Example -N/export/data2/san_juan/taup_file tells the
program to look for file 'taup_file' in directory
'/export/data2/san_juan'. The first nang=ntrace-1
traces of each input gather correspond to the nang
(p,q) apparent moveouts or (dip,azimuth) pairs searched
in routine semb3d. The last trace is an integer pointer
that indicates which angle has the highest semblance at
each time sample.
-O file_out
Enter the output multi-attribute data set name or file
immediately after typing -O. Attributes will be output
back to back, line by line, with the instanteous
envelope attribute (if -IE is entered) first, the
instantanous phase attribute (if -IP is entered)
second, the instantaneous frequency attribute (if -IF
is entered) third, etc. This output file name is not
required when piping the output to another process.
-IE file_ienv
Enter -IE followed by the instantaneous envelope
(amplitude) file name to output this attribute to a
separate file. If -IE is entered with no file name,
this attribute will be directed to the file or pipe
defined by the -O option above.
-IP file_iphase
Enter -IP followed by the instantaneous phase file name
to output this attribute to a separate file. If -IP is
entered with no file name, this attribute will be
directed to the file or pipe defined by the -O option
above. The phase will range between 0 and 180 degrees.
-IF file_ifreq
Enter -IF followed by the instantaneous frequency file
name to output this attribute to a separate file. If
-IF is entered with no file name, this attribute will
be directed to the file or pipe defined by the -O
option above. The frequency will be truncated to fall
between 0 Hz and Nyquist (1./(2.*dt)).
-IBW file_ibw
Enter -IBW followed by the instantaneous bandwidth file
name to output this attribute to a separate file. If
-IBW is entered with no file name, this attribute will
be directed to the file or pipe defined by the -O
option above.
-RE file_renv
Enter -RE followed by the response envelope (amplitude)
file name to output this attribute to a separate file.
If -RE is entered with no file name, this attribute
will be directed to the file or pipe defined by the -O
option above.
-RP file_rphase
Enter -RP followed by the response phase file name to
output this attribute to a separate file. If -RP is
entered with no file name, this attribute will be
directed to the file or pipe defined by the -O option
above. The phase will range between 0 and 180 degrees.
-RF file_rfreq
Enter -RF followed by the response frequency file name
to output this attribute to a separate file. If -RF is
entered with no file name, this attribute will be
directed to the file or pipe defined by the -O option
above. The frequency will be truncated to fall between
0 Hz and Nyquist (1./(2.*dt)).
-RBW file_rbw
Enter -RBW followed by the response bandwidth file name
to output this attribute to a separate file. If -RBW is
entered with no file name, this attribute will be
directed to the file or pipe defined by the -O
option above.
-RL file_rlength
Enter -RL followed by the response length file name to
output this attribute to a separate file. If -RL is
entered with no file no file name, this attribute will
be directed to the file or pipe defined by the -O
option above.
-C file_carrier
Enter -C followed by the carrier file name to output
this attribute to a separate file. If -C is entered
with no file name, this attribute will be directed to
the file or pipe defined by the -O option above.
-S file_skewness
Enter -S followed by the skewness file name to output
this attribute to a separate file. If -S is entered
with no file name, this attribute will be directed to
the file or pipe defined by the -O option above.
-RT file_risetime
Enter -RT followed by the rise time file name to output
this attribute to a separate file. If -RT is entered
with no file name, this attribute will be directed to
the file or pipe defined by the -O option above.
-P0 file_phase0
Enter -P0 followed by the 0 degree phase decomposition
file name to output the decomposition calculation to a
separate file. If -P0 is entered with no file name,
this attribute will be directed to the file or pipe
defined by the -O option above.
-P90 file_phase90
Enter -P90 followed by the 90 degree phase decomposi-
tion file name to output the decomposition calculation
to a separate file. If -P90 is entered with no file
name, this attribute will be directed to the file or
pipe defined by the -O option above.
-V Enter the command line argument '-V' to get additional
printout.
-? Enter the command line argument '-?' to get online
help. The program terminates
after the help screen is printed.
EXAMPLE 1:
Run program asig3d with semb3d without generating an inter-
mediate
disk file. Here the user will need to write a shell script
that exploits a named pipe:
#! /bin/sh -f
#
# beginning of sample script
#
# open a named pipe 'file' called 'file_taup' using the 'mknod' command.
# the trailing 'p' indicates a memory to memory pipe.
#
mknod file_taup p
#
# fire up program semb3d in the background. The (tau,p,q) gathers will be
# ouput to the named pipe.
#
semb3d -Nfile_seismic -dx25 -dz25 -smax.25 -rad50 -Ssemblance -taupfile_taup &
#
# fire up program asig3d in the background. The (tau,p,q) gathers will be
# input using the named pipe.
#
asig3d -Nfile_taup -IEinst_envelope -RPresp_phase -RBWresponse_bw -RFresponse_frequency &
#
# script will exit when the output to the named pipe in program semb3d is
# completed.
#
# end of script
#
exit 0
EXAMPLE 2:
Run a Landmark SeisWorks '3dv' format file into semb3d run-
ning on the HP cluster node gsclus01. Take the (tau,p,q)
gathers from semb3d and feed them into asig3d running on
node gsclus02. Take the output from asig3d and feed them
back into sistolm3dv running on node gsclus03. Use named
pipes to eliminate the need for intermediate large 3D data
volumes on the HP cluster.
#! /bin/sh -f
#
# beginning of script
#
# open 3 named pipe 'files', 1 between semb3d and asig3d, 2 between
# asig3d and sistolm3dv.
#
mknod file_taup p
mknod envfile p
mknod phasefile p
#
# use conventional pipe to transfer input data from fB
ddd# semb3d and output semblance data from semb3d into
# sistolm3dv. Fire up all programs in background in order to use
# named pipes.
#
lm3dvtosis -project l5vdec -input rwdec01.3dv \
-startline 1179 -endline 1187 -starttrace 530 -endtrace 1500 | \
(rsh gsclus01 asig3d -S -dx25 -dy25 -mx1 -my1 -smax.25 -taupfile_taup | \
sistolm3dv -project l5vdec -output semb01.3dv &
rsh gsclus02 asig3d -Nfile_taup -IEfile_env -IPphasefile &
rsh gsclus03 sistolm3dv -input file_env -project l5vdec -output env01.3dv &
rsh gsclus03 sistolm3dv -input file_phase -project l5vdec -output pha01.3dv &
#
# end of script
#
exit 0
See Also:
semb3d, asig, XIKP, lm3dvtosis, sistolm3dv
REFERENCES:
Taner, M. T., Koehler, F. and Sheriff, R. E., 1979, Complex
seismic trace analysis, Geophysics, 44, 1041-1063.
Cohen and Lee, 1993, Proc. IEEE Int. Conf. Acoust. Speech,
Signal Proceesing.
Marfurt, K.J., Kirlin, R.L., Bahorich, M.S, and Farmer,
S.F., 1994, 3D seismic attributes using a running window
semblance technique. Geoscience Research Bulletin (in
press).
Bohorich, M.S. and Farmer, S.L. (1992) The seismic sequence
attribute map, Geos cience Research Note GRN9205.
Bohorich, M.S. and Farmer, S.L. (1994) 3D seismic coherency
for faults and strat igraphic features, Geoscience Research
Note GRN9408.
CONTRACT AGREEMENT
This product is brought to you by Research Agreement #548
(The Seismic Coherency Cube). Thank you for your support.
AUTHOR
Kurt. J. Marfurt (E&PTG, Tulsa, OK, USA) Built on earlier
work (program asig) by John Bodine and Don Wagner.
COPYRIGHT
copyright 2001, Amoco Production Company
All Rights Reserved
an affiliate of BP America Inc.
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