Thread: Fwd: segy2sac

Started: 2016-07-19 23:15:52
Last activity: 2016-07-23 19:49:33
Topics: SAC Help
Abhash Kumar
2016-07-19 23:15:52
Hi,
I am using "segy2sac" to convert SEG-Y files into SAC format and check
the header information. I am successfully able to convert first 9 files
from the SEG-Y directory into SAC format using following syntax:

segy2sac -d SAC -g segy_file

When I try to convert other files from the SEG-Y directory, I get an error
of "Abort trap: 6". I looked online to find help for this error and it
seems to be related to memory issue. I have enough memory and
administrative right to the working directory. I have attached few example
files for which segy2sac does not work on my computer. Can someone try
segy2sac on the attached files. I would be extremely grateful for any
suggestion to resolve this issue.

Best regards
Abhash Kumar

  • Milton Plasencia
    2016-07-21 20:15:13
    Abhash,

    SEG-Y is platform dependent, so in my linux box (CentOS x86_64) i convert your files without problem.

    milton@pcasain7:~/Temp$ segy2sac -d SAC s0001f001*
    segy2sac: Version Number 2002.059

    converting s0001f0010 ==> SAC/s0001f0010.sac
    converting s0001f0011 ==> SAC/s0001f0011.sac
    converting s0001f0012 ==> SAC/s0001f0012.sac

    HTH,

    Milton



    * * * * * * * * * * * * * * * * * * * * * * *
    Milton P. PLASENCIA LINARES

    Centro di Ricerche Sismologiche (CRS)
    OGS - Istituto Nazionale di Oceanografia e di Geofisica Sperimentale

    Borgo Grotta Gigante 42/C
    (34010) Sgonico - Trieste - Italia
    Tel: +39 040 2140 156 (Udine)
    Tel: +39 040 2140 256 (Trieste)
    Cel.: +39 331 6481 935

    E-mail: mplasencia<at>inogs.it
    GPG key: 22FCFFA8

    ASAIN (Antarctic Seismographic Argentinean Italian Network)
    *********************************

    On Jul 19, 2016, at 22:16, Abhash Kumar <abhash.kumar84<at>gmail.com> wrote:


    Hi,
    I am using "segy2sac" to convert SEG-Y files into SAC format and check the header information. I am successfully able to convert first 9 files from the SEG-Y directory into SAC format using following syntax:

    segy2sac -d SAC -g segy_file

    When I try to convert other files from the SEG-Y directory, I get an error of "Abort trap: 6". I looked online to find help for this error and it seems to be related to memory issue. I have enough memory and administrative right to the working directory. I have attached few example files for which segy2sac does not work on my computer. Can someone try segy2sac on the attached files. I would be extremely grateful for any suggestion to resolve this issue.

    Best regards
    Abhash Kumar

    <s0001f0010><s0001f0011><s0001f0012>
    ----------------------
    SAC Help (http://ds.iris.edu/message-center/topic/sac-help/)

    Sent via IRIS Message Center (http://ds.iris.edu/message-center/)
    Update subscription preferences at http://ds.iris.edu/account/profile/


    • George Helffrich
      2016-07-22 04:01:18
      Dear Milton -

      segy2sac may be platform dependent, but the SEG-Y standard is not. To quote from the standard (Norris, M. W., Faichney, A. K., eds. (2002). "SEG Y rev 1 Data Exchange
      format", Society of Exploration Geophysics)”

      3.3. Number Formats

      In the 1975 SEG Y standard, all binary values are defined as using “big-endian” byte ordering. This conformed to the IBM tape standard and means that, within the bytes that make up a number, the most significant byte (containing the sign bit) is written closest to the beginning of the file and the least significant byte is written closest to the end of the file. This byte ordering convention is maintained in this revision of the SEG Y format and it should be adhered to for all conforming versions of SEG Y. This is independent of the medium to which a particular SEG Y file is written (i.e. the byte ordering is no different if the file is written to tape on a mainframe or to disk on a PC).

      The one file that I examined (I assume the others were the same) was written in little-endian format, in other words, in contravention of the standard. Hence the files are not SEG-Y.

      On 21 Jul 2016, at 20:16, Milton Plasencia <mplasencia<at>inogs.it> wrote:

      Abhash,

      SEG-Y is platform dependent, so in my linux box (CentOS x86_64) i convert your files without problem.

      milton@pcasain7:~/Temp$ segy2sac -d SAC s0001f001*
      segy2sac: Version Number 2002.059

      converting s0001f0010 ==> SAC/s0001f0010.sac
      converting s0001f0011 ==> SAC/s0001f0011.sac
      converting s0001f0012 ==> SAC/s0001f0012.sac

      HTH,

      Milton



      * * * * * * * * * * * * * * * * * * * * * * *
      Milton P. PLASENCIA LINARES

      Centro di Ricerche Sismologiche (CRS)
      OGS - Istituto Nazionale di Oceanografia e di Geofisica Sperimentale

      Borgo Grotta Gigante 42/C
      (34010) Sgonico - Trieste - Italia
      Tel: +39 040 2140 156 (Udine)
      Tel: +39 040 2140 256 (Trieste)
      Cel.: +39 331 6481 935

      E-mail: mplasencia<at>inogs.it
      GPG key: 22FCFFA8

      ASAIN (Antarctic Seismographic Argentinean Italian Network)
      *********************************

      On Jul 19, 2016, at 22:16, Abhash Kumar <abhash.kumar84<at>gmail.com> wrote:


      Hi,
      I am using "segy2sac" to convert SEG-Y files into SAC format and check the header information. I am successfully able to convert first 9 files from the SEG-Y directory into SAC format using following syntax:

      segy2sac -d SAC -g segy_file

      When I try to convert other files from the SEG-Y directory, I get an error of "Abort trap: 6". I looked online to find help for this error and it seems to be related to memory issue. I have enough memory and administrative right to the working directory. I have attached few example files for which segy2sac does not work on my computer. Can someone try segy2sac on the attached files. I would be extremely grateful for any suggestion to resolve this issue.

      Best regards
      Abhash Kumar

      <s0001f0010><s0001f0011><s0001f0012>
      ----------------------
      SAC Help (http://ds.iris.edu/message-center/topic/sac-help/)

      Sent via IRIS Message Center (http://ds.iris.edu/message-center/)
      Update subscription preferences at http://ds.iris.edu/account/profile/


      ----------------------
      SAC Help (http://ds.iris.edu/message-center/topic/sac-help/)

      Sent via IRIS Message Center (http://ds.iris.edu/message-center/)
      Update subscription preferences at http://ds.iris.edu/account/profile/



      George Helffrich
      george.helffrich<at>bris.ac.uk


      • Milton Plasencia
        2016-07-21 21:07:30
        Dear George,

        Thanks for clarifying about the SEG-Y format, i will read the document.

        Cheers,

        Milton


        * * * * * * * * * * * * * * * * * * * * * * *
        Milton P. PLASENCIA LINARES

        Centro di Ricerche Sismologiche (CRS)
        OGS - Istituto Nazionale di Oceanografia e di Geofisica Sperimentale

        Borgo Grotta Gigante 42/C
        (34010) Sgonico - Trieste - Italia
        Tel: +39 040 2140 156 (Udine)
        Tel: +39 040 2140 256 (Trieste)
        Cel.: +39 331 6481 935

        E-mail: mplasencia<at>inogs.it
        GPG key: 22FCFFA8

        ASAIN (Antarctic Seismographic Argentinean Italian Network)
        *********************************

        On Jul 21, 2016, at 14:01, George Helffrich <George.Helffrich<at>bristol.ac.uk> wrote:

        Dear Milton -

        segy2sac may be platform dependent, but the SEG-Y standard is not. To quote from the standard (Norris, M. W., Faichney, A. K., eds. (2002). "SEG Y rev 1 Data Exchange
        format", Society of Exploration Geophysics)”

        3.3. Number Formats

        In the 1975 SEG Y standard, all binary values are defined as using “big-endian” byte ordering. This conformed to the IBM tape standard and means that, within the bytes that make up a number, the most significant byte (containing the sign bit) is written closest to the beginning of the file and the least significant byte is written closest to the end of the file. This byte ordering convention is maintained in this revision of the SEG Y format and it should be adhered to for all conforming versions of SEG Y. This is independent of the medium to which a particular SEG Y file is written (i.e. the byte ordering is no different if the file is written to tape on a mainframe or to disk on a PC).

        The one file that I examined (I assume the others were the same) was written in little-endian format, in other words, in contravention of the standard. Hence the files are not SEG-Y.

        On 21 Jul 2016, at 20:16, Milton Plasencia <mplasencia<at>inogs.it <mplasencia<at>inogs.it>> wrote:

        Abhash,

        SEG-Y is platform dependent, so in my linux box (CentOS x86_64) i convert your files without problem.

        milton@pcasain7:~/Temp$ segy2sac -d SAC s0001f001*
        segy2sac: Version Number 2002.059

        converting s0001f0010 ==> SAC/s0001f0010.sac
        converting s0001f0011 ==> SAC/s0001f0011.sac
        converting s0001f0012 ==> SAC/s0001f0012.sac

        HTH,

        Milton



        * * * * * * * * * * * * * * * * * * * * * * *
        Milton P. PLASENCIA LINARES

        Centro di Ricerche Sismologiche (CRS)
        OGS - Istituto Nazionale di Oceanografia e di Geofisica Sperimentale

        Borgo Grotta Gigante 42/C
        (34010) Sgonico - Trieste - Italia
        Tel: +39 040 2140 156 (Udine)
        Tel: +39 040 2140 256 (Trieste)
        Cel.: +39 331 6481 935

        E-mail: mplasencia<at>inogs.it <mplasencia<at>inogs.it>
        GPG key: 22FCFFA8

        ASAIN (Antarctic Seismographic Argentinean Italian Network)
        *********************************

        On Jul 19, 2016, at 22:16, Abhash Kumar <abhash.kumar84<at>gmail.com <abhash.kumar84<at>gmail.com>> wrote:


        Hi,
        I am using "segy2sac" to convert SEG-Y files into SAC format and check the header information. I am successfully able to convert first 9 files from the SEG-Y directory into SAC format using following syntax:

        segy2sac -d SAC -g segy_file

        When I try to convert other files from the SEG-Y directory, I get an error of "Abort trap: 6". I looked online to find help for this error and it seems to be related to memory issue. I have enough memory and administrative right to the working directory. I have attached few example files for which segy2sac does not work on my computer. Can someone try segy2sac on the attached files. I would be extremely grateful for any suggestion to resolve this issue.

        Best regards
        Abhash Kumar

        <s0001f0010><s0001f0011><s0001f0012>
        ----------------------
        SAC Help (http://ds.iris.edu/message-center/topic/sac-help/)

        Sent via IRIS Message Center (http://ds.iris.edu/message-center/)
        Update subscription preferences at http://ds.iris.edu/account/profile/


        ----------------------
        SAC Help (http://ds.iris.edu/message-center/topic/sac-help/)

        Sent via IRIS Message Center (http://ds.iris.edu/message-center/)
        Update subscription preferences at http://ds.iris.edu/account/profile/



        George Helffrich
        george.helffrich<at>bris.ac.uk <george.helffrich<at>bris.ac.uk>



        • Ayele
          2016-07-22 22:04:13
          Dear SAC users,
          I installed SAC 101.6a version on my ubuntu 12.04 Linux system. I tried to read sac files obtained from IRIS and decompressed using rdseed program. I got the following error message but the issue is not byte-swapping problem.
          SAC> r sacfile
          ERROR 1318: Header in disk file is out of date: sacfile
          Header version number is incorrect.
          Header seems byte-swapped -- byte-swap file and retry. 

          Any help would be appreciated.
          With regards,Atalay



          • George Helffrich
            2016-07-23 15:24:33
            Dear Atalay -

            This looks like a message produced by SAC/BRIS not SAC/IRIS. If you are actually using that, the utility program "sactosac -m” will convert files to big-endian format. Otherwise I don’t know why SAC should care about byte-swapping a file.

            On 23 Jul 2016, at 00:05, Ayele <atawon<at>yahoo.com> wrote:

            Dear SAC users,

            I installed SAC 101.6a version on my ubuntu 12.04 Linux system. I tried to read sac files obtained from IRIS and decompressed using rdseed program. I got the following error message but the issue is not byte-swapping problem.

            SAC> r sacfile

            ERROR 1318: Header in disk file is out of date: sacfile
            Header version number is incorrect.
            Header seems byte-swapped -- byte-swap file and retry.

            Any help would be appreciated.

            With regards,
            Atalay




            ----------------------
            SAC Help (http://ds.iris.edu/message-center/topic/sac-help/)

            Sent via IRIS Message Center (http://ds.iris.edu/message-center/)
            Update subscription preferences at http://ds.iris.edu/account/profile/


            George Helffrich
            george.helffrich<at>bris.ac.uk


            • Ayele
              2016-07-23 19:49:33
              Dear George,
              Yes you are right! There were two path specifications for SAC/BRIS that I didn't know and I thought it was commented but there was one at the end of the .bashrc file.
              Thanks for the help.Atalay

              On Saturday, July 23, 2016 1:24 AM, George Helffrich <George.Helffrich<at>bristol.ac.uk> wrote:


              Dear Atalay -
              This looks like a message produced by SAC/BRIS not SAC/IRIS.  If you are actually using that, the utility program "sactosac -m” will convert files to big-endian format.  Otherwise I don’t know why SAC should care about byte-swapping a file.
              On 23 Jul 2016, at 00:05, Ayele <atawon<at>yahoo.com> wrote:

              Dear SAC users,
              I installed SAC 101.6a version on my ubuntu 12.04 Linux system. I tried to read sac files obtained from IRIS and decompressed using rdseed program. I got the following error message but the issue is not byte-swapping problem.
              SAC> r sacfile
              ERROR 1318: Header in disk file is out of date: sacfile
              Header version number is incorrect.
              Header seems byte-swapped -- byte-swap file and retry. 

              Any help would be appreciated.
              With regards,Atalay



              ----------------------
              SAC Help (http://ds.iris.edu/message-center/topic/sac-help/)

              Sent via IRIS Message Center (http://ds.iris.edu/message-center/)
              Update subscription preferences at http://ds.iris.edu/account/profile/



                        George Helffrich
                        george.helffrich<at>bris.ac.uk




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