Thread: FIR filter part of the instrument response

Started: 2014-02-19 04:18:11
Last activity: 2014-02-19 15:27:30
Topics: SAC Help
Patty
2014-02-19 04:18:11
Hi all,

I have two RESP files.
These two are very similar except numerator coefficients are different at 3
stages. Gain and sensitivity values are all the same.

But it seems to me that SAC does not have a way to keep track of the
digital/FIR filter part of the instrument response. Therefore, no matter
which RESP file I used, the amplitudes of traces after removing instrument
response are still the same. but it should be 2.94 times different.

Do anyone have a clue how we can retrieve a pole-zero file which
considering gain and the numerator coefficients in all stages?

Thank you.

Cheers,
Patty

--
********************************************
Peiying Patty Lin
Postdoctoral Research Scientist
Lamont Doherty Earth Observatory
http://www.ldeo.columbia.edu/~pattylin/
********************************************

  • Milton Plasencia
    2014-02-19 15:27:30
    Hi Patty,

    In general the sensitivities of digital filters are 1.
    But, for this need check the code of transfer if
    it considers these sensitivities.

    Can you share your resp files?

    Cheers,

    Milton

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    On Feb 19, 2014, at 2:18 AM, Peiying Lin <patty.lin<at>asu.edu> wrote:

    Hi all,

    I have two RESP files.
    These two are very similar except numerator coefficients are different at 3 stages. Gain and sensitivity values are all the same.

    But it seems to me that SAC does not have a way to keep track of the digital/FIR filter part of the instrument response. Therefore, no matter which RESP file I used, the amplitudes of traces after removing instrument response are still the same. but it should be 2.94 times different.

    Do anyone have a clue how we can retrieve a pole-zero file which considering gain and the numerator coefficients in all stages?

    Thank you.

    Cheers,
    Patty

    --
    ********************************************
    Peiying Patty Lin
    Postdoctoral Research Scientist
    Lamont Doherty Earth Observatory
    http://www.ldeo.columbia.edu/~pattylin/
    ********************************************
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02:27:46 v.22510d55