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 Unix, Linux and Mac OS X 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 the 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 entire contents of 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. 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 help utilities once 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) to create the four subdirectories and write the scripts to the SU subdirectory. Step 2. Make sure 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= directory location of the SEG Y file (absolute or relative path) 2= file name (without the .TRA extension) 3= output directory (without the /SU) example: llnew ../segy sj21 .. 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 example, .100) 3= directory location of the SU-formatted data (without the /SU) 4= SU file name (without the .su extension) 5= height of the plot in inches (try 8) 6= pclip value (try 95 - higher is lighter, lower is darker) example: boom 0 .100 .. sj21 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, ImageMagick for GIF images, or Ghostview for Postscript files. The files listed below are used 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 instructions. 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.