Thread: Who has the zero-polar file for Guralp CMG-3ESPC?

Started: 2010-04-16 01:34:08
Last activity: 2010-10-13 23:06:00
Topics: SAC Help
Hi, all,

does anyone know the zero-polar points for Guralp CMG-3ESPC?

Thx.

Lee
2010-04-15




  • Sheila Peacock
    2010-04-15 18:57:25
    You can get the data sheets for your particular
    Guralp seismometer by emailing "caldoc<at>guralp.com"
    with the serial number of the seismometer in the
    subject line. It also works for digitisers, but
    for both, only if they were recently manufactured.
    The reply consists of Microsoft Word documents.
    Beware that these DO NOT OPEN PROPERLY in OpenOffice
    - always open them in a genuine copy of Microsoft
    Word.

    also beware that the poles and zeros are for
    velocity in Hz not displacement in radians,
    and have to be converted for SAC.


    Sheila Peacock
    Blacknest

  • Dear Lee,

    I attached a 3ESPC calibration document from Guralp. Generaly they have the same Pole-Zero values. I recommend that you should send a mail to
    caldoc<at>guralp.com. write the sensor and digitizer serial numbers (i.e. T3W49, A203, T3W50, B201) in to the subject part. The system sends back the doc files. If you can not get files write to support team at Guralp. They will send you manually.

    The main point is that you must convert the poles-zeros in the document in to radian (poles*2*pi*f) for SAC, and add 1 extra zero for integration. and convert A0 value to radian and displacement (see the pdf file) type.

    best regards
    onur

    Dr. Onur TAN
    ---------------------------------------------- 40.7866N 29.4500E ---------
    TÜBİTAK Marmara Araştırma Merkezi, Yer ve Deniz Bilimleri Enstitüsü
    TUBITAK Marmara Research Center, Earth and Marine Sciences Institute
    Gebze - Kocaeli - TURKEY



    On 15.04.2010 13:34, "Lee" <pku132<at>163.com> wrote:

    Hi, all,

    does anyone know the zero-polar points for Guralp CMG-3ESPC?

    Thx.

    Lee
    2010-04-15



    _______________________________________________
    sac-help mailing list
    sac-help<at>iris.washington.edu
    http://www.iris.washington.edu/mailman/listinfo/sac-help



    • Sheila Peacock
      2010-04-15 23:33:19
      The 3ESPC calibration documents
      that I have seen are specified in velocity so the
      instructions below are probably correct. Read the
      calibration document from Guralp carefully: some
      Guralp seismometers have poles and zeros specified in
      acceleration, so you have to add TWO zeros to integrate
      to displacement for SAC. Check that your
      calibration document says "velocity response output"
      above the list of poles.

      Sheila P.

      Onur Tan wrote:
      Dear Lee,

      I attached a 3ESPC calibration document from Guralp. Generaly they have the same Pole-Zero values. I recommend that you should send a mail to
      caldoc<at>guralp.com. write the sensor and digitizer serial numbers (i.e. T3W49, A203, T3W50, B201) in to the subject part. The system sends back the doc files. If you can not get files write to support team at Guralp. They will send you manually.

      The main point is that you must convert the poles-zeros in the document in to radian (poles*2*pi*f) for SAC, and add 1 extra zero for integration. and convert A0 value to radian and displacement (see the pdf file) type.

      best regards
      onur

      Dr. Onur TAN
      ---------------------------------------------- 40.7866N 29.4500E ---------
      TÜBİTAK Marmara Araştırma Merkezi, Yer ve Deniz Bilimleri Enstitüsü
      TUBITAK Marmara Research Center, Earth and Marine Sciences Institute
      Gebze - Kocaeli - TURKEY



      On 15.04.2010 13:34, "Lee" <pku132<at>163.com> wrote:

      Hi, all,

      does anyone know the zero-polar points for Guralp CMG-3ESPC?

      Thx.

      Lee
      2010-04-15



      _______________________________________________
      sac-help mailing list
      sac-help<at>iris.washington.edu
      http://www.iris.washington.edu/mailman/listinfo/sac-help




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  • Despina Kementzetzidou
    2010-04-15 21:43:35

    For the model of 60sec I have the following prices (all in rads, velocity)/

    Kony

    SENSOR Model SENSOR SENSITIVITY (V/m/sec) A0 (velocity) DIGITIZER
    SENSITIVITY (cnts/V) SAC CONSTANT (displacement, add 1 more zero)
    ZEROS POLES ZERO 1r ZERO 1im ZERO 2r ZERO 2im POLE 1r POLE 1im
    POLE 2r POLE 2im POLE 3r POLE 3im POLE 4r POLE 4im POLE 5r POLE 5im
    CMG-3ESPC/60sec 1950 5.71508E+08 400000 4.46E+17 2 5 0 0 0 0
    -502.655 0 -1005.31 0 -1130.97 0 -0.07402 0.074016 -0.07402
    -0.07402




    Lee wrote:
    Hi, all,

    does anyone know the zero-polar points for Guralp CMG-3ESPC?

    Thx.

    Lee
    2010-04-15



    _______________________________________________
    sac-help mailing list
    sac-help<at>iris.washington.edu
    http://www.iris.washington.edu/mailman/listinfo/sac-help




    • It's been a while since I worried about this, and I've screwed things
      up a bit.

      I requested some data from the DMC, using Standing Order for Data
      (SOD). It is big-endian. When I write a sac file on my x86 computer,
      the sac file seems to be in little-endian format (the native format);
      however, when I just write headers to the original sac file, the file
      stays in the big-endian format.

      I'd like all my data to be in one format, preferably the native,
      little-endian, format. I can use sacswap to change format, but it
      seems to work indiscriminantly on files, swapping them even if they are
      in the native format.

      So, I was wondering:
      1) If there is any way to make sac write files in the same
      byte-order that the file was read in
      2) is there a more elegant way to work with sacswap, to get it to
      only swap non-native byte order files. I think the mac version of
      sacswap does do this.

      I realize now I should have used the <littleEndian/> tag in my SOD
      request, and it's actually not to hard to retrace my steps and run
      sacswap on the files that need to be swapped. But I can't help if
      there is a more elegant way to do this...

      Thanks,

      Derek

      --
      --------------------
      Derek Schutt
      Assistant Professor
      Geosciences Department
      309 Natural Resources Building
      Campus Delivery 1482
      Fort Collins, CO 80525-1482
      http://warnercnr.colostate.edu/~schutt/CSU_web/index.htm
      970-491-5786


      • Derek,

        This is the second request for this feature recently and it should not
        take much to add in this type of functionality. It will most likely be
        designed as an option you would need to turn on, but this should. I
        will add this to my list of things to do.

        Brian

        On Oct 12, 2010, at 6:38 PM, Derek Schutt wrote:

        It's been a while since I worried about this, and I've screwed
        things up a bit.

        I requested some data from the DMC, using Standing Order for Data
        (SOD). It is big-endian. When I write a sac file on my x86
        computer, the sac file seems to be in little-endian format (the
        native format); however, when I just write headers to the original
        sac file, the file stays in the big-endian format.

        I'd like all my data to be in one format, preferably the native,
        little-endian, format. I can use sacswap to change format, but it
        seems to work indiscriminantly on files, swapping them even if they
        are in the native format.

        So, I was wondering:
        1) If there is any way to make sac write files in the same byte-
        order that the file was read in
        2) is there a more elegant way to work with sacswap, to get it to
        only swap non-native byte order files. I think the mac version of
        sacswap does do this.

        I realize now I should have used the <littleEndian/> tag in my SOD
        request, and it's actually not to hard to retrace my steps and run
        sacswap on the files that need to be swapped. But I can't help if
        there is a more elegant way to do this...

        Thanks,

        Derek

        --
        --------------------
        Derek Schutt
        Assistant Professor
        Geosciences Department
        309 Natural Resources Building
        Campus Delivery 1482
        Fort Collins, CO 80525-1482
        http://warnercnr.colostate.edu/~schutt/CSU_web/index.htm
        970-491-5786

        _______________________________________________
        sac-help mailing list
        sac-help<at>iris.washington.edu
        http://www.iris.washington.edu/mailman/listinfo/sac-help



        • Thanks Brian. I appreciate your efforts.

          -Derek

          On 10/13/2010 08:18 AM, Brian Savage wrote:
          Derek,

          This is the second request for this feature recently and it should not
          take much to add in this type of functionality. It will most likely be
          designed as an option you would need to turn on, but this should. I
          will add this to my list of things to do.

          Brian

          On Oct 12, 2010, at 6:38 PM, Derek Schutt wrote:

          It's been a while since I worried about this, and I've screwed things
          up a bit.

          I requested some data from the DMC, using Standing Order for Data
          (SOD). It is big-endian. When I write a sac file on my x86
          computer, the sac file seems to be in little-endian format (the
          native format); however, when I just write headers to the original
          sac file, the file stays in the big-endian format.

          I'd like all my data to be in one format, preferably the native,
          little-endian, format. I can use sacswap to change format, but it
          seems to work indiscriminantly on files, swapping them even if they
          are in the native format.

          So, I was wondering:
          1) If there is any way to make sac write files in the same
          byte-order that the file was read in
          2) is there a more elegant way to work with sacswap, to get it to
          only swap non-native byte order files. I think the mac version of
          sacswap does do this.

          I realize now I should have used the <littleEndian/> tag in my SOD
          request, and it's actually not to hard to retrace my steps and run
          sacswap on the files that need to be swapped. But I can't help if
          there is a more elegant way to do this...

          Thanks,

          Derek

          --
          --------------------
          Derek Schutt
          Assistant Professor
          Geosciences Department
          309 Natural Resources Building
          Campus Delivery 1482
          Fort Collins, CO 80525-1482
          http://warnercnr.colostate.edu/~schutt/CSU_web/index.htm
          970-491-5786

          _______________________________________________
          sac-help mailing list
          sac-help<at>iris.washington.edu
          http://www.iris.washington.edu/mailman/listinfo/sac-help


          _______________________________________________
          sac-help mailing list
          sac-help<at>iris.washington.edu
          http://www.iris.washington.edu/mailman/listinfo/sac-help



          --
          --------------------
          Derek Schutt
          Assistant Professor
          Geosciences Department
          309 Natural Resources Building
          Campus Delivery 1482
          Fort Collins, CO 80525-1482
          http://warnercnr.colostate.edu/~schutt/CSU_web/index.htm
          970-491-5786


      • Hi

        You could take a look at a small program that I wrote that can do it for
        you. The name of the program is sacswapbyte.
        You can check it from my webpage ...

        http://sites.google.com/site/foo4funreborn/

        From this program you can pass in many files and say that I want that the
        output should be little or big and will find out wich files need to be
        converted and those that should not be changed. Also there are other tools
        (sactools) on my webpage for handling large amounts of sacdata in one run.
        Like make tables of header variables or renaming sac files ... well have a
        look !

        regards,

        marcelo
        --
        Mobile ~ +47 9080 6225
        http://sites.google.com/site/foo4funreborn/



        2010/10/13 Derek Schutt <Derek.Schutt<at>colostate.edu>

        It's been a while since I worried about this, and I've screwed things up a
        bit.

        I requested some data from the DMC, using Standing Order for Data (SOD).
        It is big-endian. When I write a sac file on my x86 computer, the sac file
        seems to be in little-endian format (the native format); however, when I
        just write headers to the original sac file, the file stays in the
        big-endian format.

        I'd like all my data to be in one format, preferably the native,
        little-endian, format. I can use sacswap to change format, but it seems to
        work indiscriminantly on files, swapping them even if they are in the native
        format.

        So, I was wondering:
        1) If there is any way to make sac write files in the same byte-order
        that the file was read in
        2) is there a more elegant way to work with sacswap, to get it to only
        swap non-native byte order files. I think the mac version of sacswap does
        do this.

        I realize now I should have used the <littleEndian/> tag in my SOD request,
        and it's actually not to hard to retrace my steps and run sacswap on the
        files that need to be swapped. But I can't help if there is a more elegant
        way to do this...

        Thanks,

        Derek

        --
        --------------------
        Derek Schutt
        Assistant Professor
        Geosciences Department
        309 Natural Resources Building
        Campus Delivery 1482
        Fort Collins, CO 80525-1482
        http://warnercnr.colostate.edu/~schutt/CSU_web/index.htmhttp://warnercnr.colostate.edu/%7Eschutt/CSU_web/index.htm
        970-491-5786

        _______________________________________________
        sac-help mailing list
        sac-help<at>iris.washington.edu
        http://www.iris.washington.edu/mailman/listinfo/sac-help


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