Seismic Unix Scripts

Seismic Unix (SU) is a public domain seismic processing software package
written and maintained by the Center for Wave Phenomena at the Colorado
School of Mines in Golden, Colorado. The web site for SU is
http://www.cwp.mines.edu/cwpcodes. SU is compatible with both UNIX and
LINUX operating systems. The SU scripts provided on this disc and listed
below were modified from scripts written by the USGS Seafloor Mapping
Group in Woods Hole, Massachusetts, and run on a LINUX workstation. These
SU scripts and other needed files and software are located in the tar file
boomll.tar, which can be found in the SU subfolder of the SOFTWARE
folder located at the top level of this disc. These scripts are provided
as examples only. They may need to be modified to run on another system.
They also require the use of shareware programs such as ImageMagick and
Ghostscript.

The example SU scripts provided here will allow the user to strip off
navigation fixes from the SEG-Y headers, along with a fix for every 500
shots, and produce a filtered and gained GIF image of each profile. These
images can then be displayed using a variety of shareware programs such as
ImageMagick (UNIX, LINUX) or a web browser. 

To use the scripts provided here you must first install SU on a UNIX or
LINUX system. The scripts require that the following four subdirectories be
created (all at the same hierarchical level) before the scripts are run:
1. SU, 2. segy, 3. seisimag, and 4. nav. If you untar the boomll.tar file,
these subdirectories will be created for you. The SU scripts and all
associated files (see below) should be placed in the SU subdirectory. You
may put the SEG-Y files in the segy subdirectory or leave them on the
disc. The GIF images will be written to the seisimag subdirectory, and the
navigation data to the nav subdirectory.

Provided below is a step-by-step explanation of the processing sequence
and example parameters required by each script. For more information
please refer to the SU documentation provided on the web or on-line
if Seismic Unix is installed on the computer. These scripts are provided
as examples only. There are many differences in versions of UNIX and
LINUX.

Step 1.  Untar the boomll.tar file (i.e., tar xvf boomll.tar), and it will
create the four subdirectories and write the scripts to the SU subdirectory.

Step 2.  Make sure the permissions for all files in the SU subdirectory
have been set to allow execution (i.e., chmod +x scriptname). These first two
steps do not need to be repeated.

Step 3.  Run llnew. This script requires the following information, in
this order, on one line, and separated by spaces:

1= the directory location of the SEG-Y file (absolute or relative path)
2= the file name (without the .TRA extension)
3= the output directory (minus the /SU)

example 1: llnew ../segy ORJ127_1 ..
example 2: llnew /cdrom/segy ORJ127_1

Step 4.  Run boom. This script requires the following information, in this
order, on one line, and separated by spaces:

1= tmin (time minimum for this data set is 0)
2= tmax (time maximum in milliseconds for this data set is .100)
3= directory location of the SU-formatted data (minus the /SU)
4= the SU file name (without the .su extension)
5= the height of the plot in inches (try 8)
6= the pclip value (try 95 - higher is lighter, lower is darker)

example 1:  boom 0 .100 .. ORJ127_1 8 95  
example 2:  boom 0 .100 /cdrom/segy/ ORJ127_1 8 95

Repeat steps 3 and 4 for each data file.

Step 5.  View the seismic profile written to the seisimag subdirectory
using a web browser, KView, or ImageMagick for GIF images, or ghostview
for Postscript files. 

The files listed below are produced or called by the SU scripts
(llnew and boom). These files will be extracted from the boomll.tar
file and placed in the SU subdirectory.

gsgifscript - needed by makegif2 to convert the Postscript image to a GIF image

history - keeps a record of the data processed and parameters used

landscape.ps - converts the Postscript plot to a landscape display direction

makegif2 - converts the Postscript image to a GIF image

Note:  These are c-shell scripts. Make sure that your .cshrc file has been
modified as per the SU installation intructions. For example, on our
system you must add the location of /opt/cwp/bin to the set path
statement. Also, a setenv statement must read setenv CWPROOT/opt/cwp.