[SAC-HELP] Response file confusion

[Rob Porritt]

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
>
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>



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