Thread: Response file confusion

Started: 2012-03-14 18:57:57
Last activity: 2012-03-14 19:14:15
Topics: SAC Help
rt wang
2012-03-14 18:57:57
Hi all,
I 've been using broadband data from IRIS on research and recently
encounter a confusing thing about response.
I am using the BH* channels of network AZ, and it should be velocity data.
I downloaded sac files from SCEC stp.
I originally request response file in SEED format, then extracted it to be
RESP.AZ.XXX..BHX, the response file.
Recently, because I want to confirm the amplitudes in velocity and also in
displacement is correct, I went to IRIS SeismiQuery to get the response
file updated until 2011. Surprisingly, the extracted response file from my
SEED format and the response file from SeismiQuery are different.
The RDSEED extracted response file has 2 zeros and 5 poles, but the
response file from SeismiQuery has 5 zeros 9 poles.
I thought 2 zeros is standard for velocity response, had no idea what the 5
zeros are. They are from the same time span for same station.

Post front portion of RESP files
1. from RDSEED:
=================================
# << IRIS SEED Reader, Release 4.7.5 >>
#
# ======== CHANNEL RESPONSE DATA ========
B050F03 Station: RDM
B050F16 Network: AZ
B052F03 Location: ??
B052F04 Channel: BHE
B052F22 Start date: 2004,056,18:43:30
B052F23 End date: No Ending Time
# =======================================
# +
+--------------------------------------------+ +
# + | Response (Poles & Zeros), RDM ch BHE
| +
# +
+--------------------------------------------+ +
#
B053F03 Transfer function type: A [Laplace Transform
(Rad/sec)]
B053F04 Stage sequence number: 1
B053F05 Response in units lookup: M/S - velocity in meters
per second
B053F06 Response out units lookup: V - emf in volts
B053F07 A0 normalization factor: 5.91892E+07
B053F08 Normalization frequency: 0.159155
B053F09 Number of zeroes: 2
B053F14 Number of poles: 5
# Complex zeroes:
# i real imag real_error imag_error
B053F10-13 0 0.000000E+00 0.000000E+00 0.000000E+00 0.000000E+00
B053F10-13 1 0.000000E+00 0.000000E+00 0.000000E+00 0.000000E+00
# Complex poles:
# i real imag real_error imag_error
B053F15-18 0 -3.701000E-02 3.701000E-02 0.000000E+00 0.000000E+00
B053F15-18 1 -3.701000E-02 -3.701000E-02 0.000000E+00 0.000000E+00
B053F15-18 2 -2.513000E+02 0.000000E+00 0.000000E+00 0.000000E+00
B053F15-18 3 -1.310000E+02 4.673000E+02 0.000000E+00 0.000000E+00
B053F15-18 4 -1.310000E+02 -4.673000E+02 0.000000E+00 0.000000E+00


2. from SeismiQuery
======================================

###################################################################################
#
B050F03 Station: RDM
B050F16 Network: AZ
B052F03 Location: ??
B052F04 Channel: BHE
B052F22 Start date: 2000,264,20:11:00
B052F23 End date: 2001,250,20:49:00
#
# +-----------------------------------+
# | Response (Poles and Zeros) |
# | AZ RDM BHE |
# | 09/20/2000 to 09/07/2001 |
# +-----------------------------------+
#
B053F03 Transfer function type: A
B053F04 Stage sequence number: 1
B053F05 Response in units lookup: M/S - velocity in meters
per second
B053F06 Response out units lookup: V - emf in volts
B053F07 A0 normalization factor: +5.74357E+12
B053F08 Normalization frequency: +2.00000E-01
B053F09 Number of zeroes: 5
B053F14 Number of poles: 9
# Complex zeroes:
# i real imag real_error imag_error
B053F10-13 0 +0.00000E+00 +0.00000E+00 +0.00000E+00 +0.00000E+00
B053F10-13 1 +0.00000E+00 +0.00000E+00 +0.00000E+00 +0.00000E+00
B053F10-13 2 -1.51500E+01 +0.00000E+00 +0.00000E+00 +0.00000E+00
B053F10-13 3 -3.18600E+02 +4.01200E+02 +0.00000E+00 +0.00000E+00
B053F10-13 4 -3.18600E+02 -4.01200E+02 +0.00000E+00 +0.00000E+00
# Complex poles:
# i real imag real_error imag_error
B053F15-18 0 -3.70000E-02 +3.70000E-02 +0.00000E+00 +0.00000E+00
B053F15-18 1 -3.70000E-02 -3.70000E-02 +0.00000E+00 +0.00000E+00
B053F15-18 2 -1.59900E+01 +0.00000E+00 +0.00000E+00 +0.00000E+00
...


Does anyone know why and how this will affect our final outcome? What are
the outputs and will they be consistent?

Thanks,

--Tien

  • Rob_Porritt
    2012-03-14 19:10:08
    Hi,

    You can use the timespan information to see a change of instrument in
    2001 and then again in 2004. I suspect the network operators for the
    ANZA array would have more information, but for practical purposes the
    important issue is to use the response which is spanning the same time
    as your data.

    see blocks:
    B052F22 Start date: 2000,264,20:11:00
    B052F23 End date: 2001,250,20:49:00

    and
    B052F22 Start date: 2004,056,18:43:30
    B052F23 End date: No Ending Time

    Cheers,
    Rob


    On Wed, Mar 14, 2012 at 11:57 AM, Tien-Huei Wang <twang024<at>ucr.edu> wrote:
    Hi all,
    I 've been using broadband data from IRIS on research and recently
    encounter a confusing thing about response.
    I am using the BH* channels of network AZ, and it should be velocity data. I
    downloaded sac files from SCEC stp.
    I originally request response file in SEED format, then extracted it to be
    RESP.AZ.XXX..BHX, the response file.
    Recently, because I want to confirm the amplitudes in velocity and also in
    displacement is correct, I went to IRIS SeismiQuery to get the response file
    updated until 2011. Surprisingly, the extracted response file from my SEED
    format and the response file from SeismiQuery are different.
    The RDSEED extracted response file has 2 zeros and 5 poles, but the response
    file from SeismiQuery has 5 zeros 9 poles.
    I thought 2 zeros is standard for velocity response, had no idea what the 5
    zeros are. They are from the same time span for same station.

    Post front portion of RESP files
    1. from RDSEED:
    =================================
    #               << IRIS SEED Reader, Release 4.7.5 >>
    #
    #               ======== CHANNEL RESPONSE DATA ========
    B050F03     Station:     RDM
    B050F16     Network:     AZ
    B052F03     Location:    ??
    B052F04     Channel:     BHE
    B052F22     Start date:  2004,056,18:43:30
    B052F23     End date:    No Ending Time
    #               =======================================
    #               +
    +--------------------------------------------+                +
    #               +               |   Response (Poles & Zeros),   RDM ch BHE
    |                +
    #               +
    +--------------------------------------------+                +
    #
    B053F03     Transfer function type:                A [Laplace Transform
    (Rad/sec)]
    B053F04     Stage sequence number:                 1
    B053F05     Response in units lookup:              M/S - velocity in meters
    per second
    B053F06     Response out units lookup:             V - emf in volts
    B053F07     A0 normalization factor:               5.91892E+07
    B053F08     Normalization frequency:               0.159155
    B053F09     Number of zeroes:                      2
    B053F14     Number of poles:                       5
    #               Complex zeroes:
    #                 i  real          imag          real_error    imag_error
    B053F10-13    0  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00
    B053F10-13    1  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00
    #               Complex poles:
    #                 i  real          imag          real_error    imag_error
    B053F15-18    0 -3.701000E-02  3.701000E-02  0.000000E+00  0.000000E+00
    B053F15-18    1 -3.701000E-02 -3.701000E-02  0.000000E+00  0.000000E+00
    B053F15-18    2 -2.513000E+02  0.000000E+00  0.000000E+00  0.000000E+00
    B053F15-18    3 -1.310000E+02  4.673000E+02  0.000000E+00  0.000000E+00
    B053F15-18    4 -1.310000E+02 -4.673000E+02  0.000000E+00  0.000000E+00


    2. from SeismiQuery
    ======================================

    ###################################################################################
    #
    B050F03     Station:     RDM
    B050F16     Network:     AZ
    B052F03     Location:    ??
    B052F04     Channel:     BHE
    B052F22     Start date:  2000,264,20:11:00
    B052F23     End date:    2001,250,20:49:00
    #
    #                  +-----------------------------------+
    #                  |    Response (Poles and Zeros)     |
    #                  |        AZ  RDM        BHE         |
    #                  |     09/20/2000 to 09/07/2001      |
    #                  +-----------------------------------+
    #
    B053F03     Transfer function type:                A
    B053F04     Stage sequence number:                 1
    B053F05     Response in units lookup:              M/S - velocity in meters
    per second
    B053F06     Response out units lookup:             V - emf in volts
    B053F07     A0 normalization factor:               +5.74357E+12
    B053F08     Normalization frequency:               +2.00000E-01
    B053F09     Number of zeroes:                      5
    B053F14     Number of poles:                       9
    #              Complex zeroes:
    #              i  real          imag          real_error    imag_error
    B053F10-13     0  +0.00000E+00  +0.00000E+00  +0.00000E+00  +0.00000E+00
    B053F10-13     1  +0.00000E+00  +0.00000E+00  +0.00000E+00  +0.00000E+00
    B053F10-13     2  -1.51500E+01  +0.00000E+00  +0.00000E+00  +0.00000E+00
    B053F10-13     3  -3.18600E+02  +4.01200E+02  +0.00000E+00  +0.00000E+00
    B053F10-13     4  -3.18600E+02  -4.01200E+02  +0.00000E+00  +0.00000E+00
    #              Complex poles:
    #              i  real          imag          real_error    imag_error
    B053F15-18     0  -3.70000E-02  +3.70000E-02  +0.00000E+00  +0.00000E+00
    B053F15-18     1  -3.70000E-02  -3.70000E-02  +0.00000E+00  +0.00000E+00
    B053F15-18     2  -1.59900E+01  +0.00000E+00  +0.00000E+00  +0.00000E+00
    ...


    Does anyone know why and how this will affect our final outcome? What are
    the outputs and will they be consistent?

    Thanks,

    --Tien

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




    --
    Rob Porritt, GG
    UC Berkeley Earth and Planetary Sciences PhD Candidate
    Berkeley Seismological Laboratory
    http://seismo.berkeley.edu/~rob/


  • Rick Benson
    2012-03-14 19:14:15
    Hi, Tien-Huei-
    The first thing to notice is that the time periods (epochs in SEED lingo)
    are different, suggesting that these are indeed different sensors,
    dataloggers, or other response characteristics.
    You need to make sure that the information is correlated by time as well.
    Hope this helps-
    Rick

    On Mar 14, 2012, at 11:57 AM, Tien-Huei Wang wrote:

    Hi all,
    I 've been using broadband data from IRIS on research and recently encounter a confusing thing about response.
    I am using the BH* channels of network AZ, and it should be velocity data. I downloaded sac files from SCEC stp.
    I originally request response file in SEED format, then extracted it to be RESP.AZ.XXX..BHX, the response file.
    Recently, because I want to confirm the amplitudes in velocity and also in displacement is correct, I went to IRIS SeismiQuery to get the response file updated until 2011. Surprisingly, the extracted response file from my SEED format and the response file from SeismiQuery are different.
    The RDSEED extracted response file has 2 zeros and 5 poles, but the response file from SeismiQuery has 5 zeros 9 poles.
    I thought 2 zeros is standard for velocity response, had no idea what the 5 zeros are. They are from the same time span for same station.

    Post front portion of RESP files
    1. from RDSEED:
    =================================
    # << IRIS SEED Reader, Release 4.7.5 >>
    #
    # ======== CHANNEL RESPONSE DATA ========
    B050F03 Station: RDM
    B050F16 Network: AZ
    B052F03 Location: ??
    B052F04 Channel: BHE
    B052F22 Start date: 2004,056,18:43:30
    B052F23 End date: No Ending Time
    # =======================================
    # + +--------------------------------------------+ +
    # + | Response (Poles & Zeros), RDM ch BHE | +
    # + +--------------------------------------------+ +
    #
    B053F03 Transfer function type: A [Laplace Transform (Rad/sec)]
    B053F04 Stage sequence number: 1
    B053F05 Response in units lookup: M/S - velocity in meters per second
    B053F06 Response out units lookup: V - emf in volts
    B053F07 A0 normalization factor: 5.91892E+07
    B053F08 Normalization frequency: 0.159155
    B053F09 Number of zeroes: 2
    B053F14 Number of poles: 5
    # Complex zeroes:
    # i real imag real_error imag_error
    B053F10-13 0 0.000000E+00 0.000000E+00 0.000000E+00 0.000000E+00
    B053F10-13 1 0.000000E+00 0.000000E+00 0.000000E+00 0.000000E+00
    # Complex poles:
    # i real imag real_error imag_error
    B053F15-18 0 -3.701000E-02 3.701000E-02 0.000000E+00 0.000000E+00
    B053F15-18 1 -3.701000E-02 -3.701000E-02 0.000000E+00 0.000000E+00
    B053F15-18 2 -2.513000E+02 0.000000E+00 0.000000E+00 0.000000E+00
    B053F15-18 3 -1.310000E+02 4.673000E+02 0.000000E+00 0.000000E+00
    B053F15-18 4 -1.310000E+02 -4.673000E+02 0.000000E+00 0.000000E+00


    2. from SeismiQuery
    ======================================

    ###################################################################################
    #
    B050F03 Station: RDM
    B050F16 Network: AZ
    B052F03 Location: ??
    B052F04 Channel: BHE
    B052F22 Start date: 2000,264,20:11:00
    B052F23 End date: 2001,250,20:49:00
    #
    # +-----------------------------------+
    # | Response (Poles and Zeros) |
    # | AZ RDM BHE |
    # | 09/20/2000 to 09/07/2001 |
    # +-----------------------------------+
    #
    B053F03 Transfer function type: A
    B053F04 Stage sequence number: 1
    B053F05 Response in units lookup: M/S - velocity in meters per second
    B053F06 Response out units lookup: V - emf in volts
    B053F07 A0 normalization factor: +5.74357E+12
    B053F08 Normalization frequency: +2.00000E-01
    B053F09 Number of zeroes: 5
    B053F14 Number of poles: 9
    # Complex zeroes:
    # i real imag real_error imag_error
    B053F10-13 0 +0.00000E+00 +0.00000E+00 +0.00000E+00 +0.00000E+00
    B053F10-13 1 +0.00000E+00 +0.00000E+00 +0.00000E+00 +0.00000E+00
    B053F10-13 2 -1.51500E+01 +0.00000E+00 +0.00000E+00 +0.00000E+00
    B053F10-13 3 -3.18600E+02 +4.01200E+02 +0.00000E+00 +0.00000E+00
    B053F10-13 4 -3.18600E+02 -4.01200E+02 +0.00000E+00 +0.00000E+00
    # Complex poles:
    # i real imag real_error imag_error
    B053F15-18 0 -3.70000E-02 +3.70000E-02 +0.00000E+00 +0.00000E+00
    B053F15-18 1 -3.70000E-02 -3.70000E-02 +0.00000E+00 +0.00000E+00
    B053F15-18 2 -1.59900E+01 +0.00000E+00 +0.00000E+00 +0.00000E+00
    ...


    Does anyone know why and how this will affect our final outcome? What are the outputs and will they be consistent?

    Thanks,

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

    ================
    Rick Benson
    Director of Data Management
    IRIS DMC
    (206)547-0393 ext. 119(office)
    rick<at>iris.washington.edu




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