Thread: Sax transfer: problem with none

Started: 2006-03-19 06:19:24
Last activity: 2006-03-21 19:45:12
Topics: SAC Help
Jim Lawson
2006-03-19 06:19:24
I had similar problems with transfer, until
I realized that whatever version I used
none did NOT mean no seismometer=earth motion.
I think "none" refers to some kind of generic
displacement transducer.

I will try to rediscover the syntax I used
in going from CMG-3 and CMG-1 to earth motion.
The transform apparently succeeded. My syntax
definitaly did not include the word "none"

Jim Lawson
OK geol. survey Leonard

  • Peter Goldstein
    2006-03-20 18:08:50

    Jim is correct. The default for transfer is displacement in nanometers.
    So, for example, transfer from "my_instrument_type" to none means that you
    are deconvolving your instrument and converting to what is hopefully a good
    representation of actual ground displacement in nanonmeters.

    At 10:19 PM +0000 3/18/06, jim<at>okgeosurvey1.gov wrote:
    I had similar problems with transfer, until
    I realized that whatever version I used
    none did NOT mean no seismometer=earth motion.
    I think "none" refers to some kind of generic
    displacement transducer.

    I will try to rediscover the syntax I used
    in going from CMG-3 and CMG-1 to earth motion.
    The transform apparently succeeded. My syntax
    definitaly did not include the word "none"

    Jim Lawson
    OK geol. survey Leonard
    _______________________________________________
    sac-help mailing list
    sac-help<at>iris.washington.edu
    http://www.iris.washington.edu/mailman/listinfo/sac-help


    --

    Peter Goldstein, Ph.D. (925) 423-1231 (office)
    L-103, PO Box 808 (925) 422-5844 (fax)
    Livermore, CA 94551 peterg<at>llnl.gov (email)
    web pages: http://earthscience.llnl.gov/peterg/
    http://www.llnl.gov/sac

    • Brian Savage
      2006-03-21 19:45:12

      Only when using the EVALRESP option is the displacement assumed to be
      nanometers (1e9). If you are using any other instrument type (polezero,
      none, fapfile, ...) it uses to what the instrument response specifies.

      None is actually a default and if an instrument response is not
      specified in the "from" to "to" it will use "none". None is a array
      with values of (1.0 +0.0i) in frequency-amplitude space or a constant
      amplitude with no phase shift.

      As I recall, doing a
      SAC> transfer from polezero sub polezero_file to none freq f1 f2 f3 f4
      where polezero_file is created by rdseed, the units are meters. The
      scale is determined by the CONSTANT in this case and the units
      (displcaement, velocity, ..) are determined by the number of zeros in
      the polezero description.

      Cheers,
      Brian


      Peter Goldstein wrote:

      Jim is correct. The default for transfer is displacement in nanometers.
      So, for example, transfer from "my_instrument_type" to none means that you
      are deconvolving your instrument and converting to what is hopefully a good
      representation of actual ground displacement in nanonmeters.

      At 10:19 PM +0000 3/18/06, jim<at>okgeosurvey1.gov wrote:
      I had similar problems with transfer, until
      I realized that whatever version I used
      none did NOT mean no seismometer=earth motion.
      I think "none" refers to some kind of generic
      displacement transducer.

      I will try to rediscover the syntax I used
      in going from CMG-3 and CMG-1 to earth motion.
      The transform apparently succeeded. My syntax
      definitaly did not include the word "none"

      Jim Lawson
      OK geol. survey Leonard
      _______________________________________________
      sac-help mailing list
      sac-help<at>iris.washington.edu
      http://www.iris.washington.edu/mailman/listinfo/sac-help




Page built 06:27:43 | v.090361a2