Thread: Re: Calculating the CONSTANT to use to remove instument response

Started: 2009-04-12 08:49:06
Last activity: 2009-04-13 00:07:38
Topics: SAC Help

Selam Melaku,

If you got the zeroes and poles files from IRIS/PASSCAL, you should be able to get the constants as well.

once you removed responses from other instruments you can run:

Trans from none to wa

if you want to simulate WA instrument record.

Good luck,



Atalay

--- On Thu, 4/9/09, Melaku Ayenew <mayenew<at>gmail.com> wrote:

From: Melaku Ayenew <mayenew<at>gmail.com>
Subject: [SAC-HELP] Calculating the CONSTANT to use to remove instument response
To: sac-help<at>iris.washington.edu
Date: Thursday, April 9, 2009, 2:50 AM
Hi All,
I am trying to remove instrument responses from STS_2,
CMG3T. CMG_ES broadband instruments. I got the poles and
zeros from IRIS Pascal Instrumentation. But I have
difficulty figuring out what constant I should use in the
*.pz file that has to read by the SAC TRANSFER command. For
example, I was trying to synthesis a WA seismogram by
removing the STS_2 response and convoulating the WA
response. I used a constant of 1 in this calcultion. The
synthesis seismogrm looks good but the displacemnt values
don't make sense (they are several hunderd meters). I
understand it is because of the CONSTANT=1 I put. My
Question is How can I calculate the correct CONSTANT that I
need to put with the zeros and poles in the SAC *.pz file.
The IRIS PASCAL instrumentation page gives the zeros and
poles and a normalization factor.

I greatly appreciate your help in this matter.

Melaku Bogale
New Mexico State University
Department of Physics
Las Cruces NM 88003-8001


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  • Hi,

    SAC PZ constant must be recalculated from the A0 value of seismometer.
    SAC PZ file is in radyan, not Hz as in Guralp calib. documents.

    you can also look this message:
    http://www.iris.washington.edu/pipermail/sac-help/2009-February/000492.html


    best regards,
    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
    ________________________________________

    Kimden: sac-help-bounces<at>iris.washington.edu [sac-help-bounces<at>iris.washington.edu], Atalay Ayele [atawon<at>yahoo.com] Adına
    Tarih: 12 Nisan 2009 Pazar 11:49
    Kime: sac-help<at>iris.washington.edu; Melaku Ayenew
    Konu: Re: [SAC-HELP] Calculating the CONSTANT to use to remove instument response

    Selam Melaku,

    If you got the zeroes and poles files from IRIS/PASSCAL, you should be able to get the constants as well.

    once you removed responses from other instruments you can run:

    Trans from none to wa

    if you want to simulate WA instrument record.

    Good luck,



    Atalay

    --- On Thu, 4/9/09, Melaku Ayenew <mayenew<at>gmail.com> wrote:

    From: Melaku Ayenew <mayenew<at>gmail.com>
    Subject: [SAC-HELP] Calculating the CONSTANT to use to remove instument response
    To: sac-help<at>iris.washington.edu
    Date: Thursday, April 9, 2009, 2:50 AM
    Hi All,
    I am trying to remove instrument responses from STS_2,
    CMG3T. CMG_ES broadband instruments. I got the poles and
    zeros from IRIS Pascal Instrumentation. But I have
    difficulty figuring out what constant I should use in the
    *.pz file that has to read by the SAC TRANSFER command. For
    example, I was trying to synthesis a WA seismogram by
    removing the STS_2 response and convoulating the WA
    response. I used a constant of 1 in this calcultion. The
    synthesis seismogrm looks good but the displacemnt values
    don't make sense (they are several hunderd meters). I
    understand it is because of the CONSTANT=1 I put. My
    Question is How can I calculate the correct CONSTANT that I
    need to put with the zeros and poles in the SAC *.pz file.
    The IRIS PASCAL instrumentation page gives the zeros and
    poles and a normalization factor.

    I greatly appreciate your help in this matter.

    Melaku Bogale
    New Mexico State University
    Department of Physics
    Las Cruces NM 88003-8001


    -----Inline Attachment Follows-----

    _______________________________________________
    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


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