I am attempting to remove the instrument response of some data. I downloaded the RESPFILE from IRIS and while using the evalresp option of transfer, I get the following error:
"WARNING (norm_resp): computed and reported sensitivities[ET.CPCT.00.HHE] differ by more than 5 percent."
I thought the final sensitivity at the end of the file is the product of all the different gain/sensitivities of each stage. When I calculate it by hand, I get the sensitivity reported. I am not sure where this error is coming from, nor I am sure how SAC calculates the sensitivity.? Thanks.
Blaine
Here is the command I use
trans from evalresp fname ET.CPCT.resp to none freqlim 0.001 0.002 15 20
"WARNING (norm_resp): computed and reported sensitivities[ET.CPCT.00.HHE] differ by more than 5 percent."
I thought the final sensitivity at the end of the file is the product of all the different gain/sensitivities of each stage. When I calculate it by hand, I get the sensitivity reported. I am not sure where this error is coming from, nor I am sure how SAC calculates the sensitivity.? Thanks.
Blaine
Here is the command I use
trans from evalresp fname ET.CPCT.resp to none freqlim 0.001 0.002 15 20

Dear Blaine,
This error is generated by evalresp. You should be able to confirm this by running evalresp on your RESP file.
For example
% evalresp CPCT HHE 2010 001 0.001 20 v f RESP.ET.CPCT.HHE.2
<< EVALRESP RESPONSE OUTPUT V3.3.3 >>
WARNING (norm_resp): computed and reported sensitivities differ by more than 5 percent.
Execution continuing.

RESP.ET.CPCT.HHE.2

ET CPCT 00 HHE 2009,001,00:00:00 2011,026,00:00:00
Seed units: Velocity(in)>Counts(out)
computed sens=1.14868E+09 (reported=1.25829E+09) @ 5.00000E02 Hz
calc_del=8.92261E01 corr_app=8.92261E01 est_delay=8.92261E01 final_sint=0.01(sec/sample)
stage 1: LAPLACE A0=6.259322E+08 NZeros= 2 NPoles= 5 Sd=1.369329E+03
stage 2: GAIN Sd=1.000000E+00
stage 3: FIR_SYM_1 H0=1.000000E+00 Ncoeff= 1 SamInt=1.953125E06 Sd=8.388610E+05
stage 4: FIR_SYM_2 H0=1.000000E+00 Ncoeff= 36 SamInt=1.953125E06 Sd=1.000000E+00
stage 5: FIR_SYM_2 H0=1.000000E+00 Ncoeff= 6 SamInt=1.562500E05 Sd=1.000000E+00
stage 6: FIR_SYM_1 H0=1.000000E+00 Ncoeff= 7 SamInt=3.125000E05 Sd=1.000000E+00
stage 7: FIR_SYM_2 H0=1.000000E+00 Ncoeff= 48 SamInt=6.250000E05 Sd=1.000000E+00
stage 8: FIR_SYM_2 H0=1.000000E+00 Ncoeff=126 SamInt=2.500000E04 Sd=1.000000E+00
stage 9: FIR_SYM_1 H0=1.000000E+00 Ncoeff=501 SamInt=5.000000E04 Sd=1.000000E+00
stage 10: FIR_SYM_1 H0=1.000000E+00 Ncoeff=501 SamInt=1.000000E03 Sd=1.000000E+00
stage 11: FIR_SYM_1 H0=1.000000E+00 Ncoeff=501 SamInt=2.000000E03 Sd=1.000000E+00

%
Possibly someone at IRIS can comment on this further. I think the first gain value is being modified due to a Analog PoleZero.
Brian
savage<at>uri.edu
On Feb 18, 2014, at 4:57 PM, Blaine Bockholt (bbckholt) wrote:
I am attempting to remove the instrument response of some data. I downloaded the RESPFILE from IRIS and while using the evalresp option of transfer, I get the following error:
"WARNING (norm_resp): computed and reported sensitivities[ET.CPCT.00.HHE] differ by more than 5 percent."
I thought the final sensitivity at the end of the file is the product of all the different gain/sensitivities of each stage. When I calculate it by hand, I get the sensitivity reported. I am not sure where this error is coming from, nor I am sure how SAC calculates the sensitivity. Thanks.
Blaine
Here is the command I use
trans from evalresp fname ET.CPCT.resp to none freqlim 0.001 0.002 15 20
_______________________________________________
sachelp mailing list
sachelp<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sachelp

Hi
Responses are at best confusing, but you need to remember that the gain is
not just a value, it is a value at a particular frequency.
The last stage (stage zero) is supposed to be the overall gain and should
be the product of the gains at each stage, but only if the frequency of
each stage is the same. In this case the stage zero gain is +1.25829E+09,
but it is given at freq of 5e2. The stage 1 gain is 1.5e3, but at a freq
of 1Hz. So to be proper, you must adjust the gain based on the poles and
zeros from 1Hz to 5e2 Hz before you multiply. Looking at the response plot
here:
http://service.iris.edu/irisws/evalresp/1/query?net=ET&sta=CPCT&loc=00&cha=HHZ&time=20090607T00:00:00&units=def&annotate=true&output=plot
it looks like 5e2 is just barely beyond the flat part of the response,
which explains why evalresp says that the stage 1 gain is 1.369329E+03
instead of 1.5e3. It has rolled off just a bit at 5e2 Hz compared to 1Hz
which is in the flat part of the response.
To be honest, I think that the mistake in this response is not in the gain
numbers, but rather in the frequency reported in the stage zero. It
probably should have the frequency in the stage zero as 1Hz instead of
5e3Hz . So, likely in this case the 1.25829E+09 is the gain you want to
use even though evalresp complains.
Hope this helps,
Philip
On Thu, Feb 20, 2014 at 1:44 PM, Brian Savage <savage<at>uri.edu> wrote:
Dear Blaine,
This error is generated by evalresp. You should be able to confirm this
by running evalresp on your RESP file.
For example
% evalresp CPCT HHE 2010 001 0.001 20 v f RESP.ET.CPCT.HHE.2
<< EVALRESP RESPONSE OUTPUT V3.3.3 >>
WARNING (norm_resp): computed and reported sensitivities differ by more
than 5 percent.
Execution continuing.

RESP.ET.CPCT.HHE.2

ET CPCT 00 HHE 2009,001,00:00:00 2011,026,00:00:00
Seed units: Velocity(in)>Counts(out)
computed sens=1.14868E+09 (reported=1.25829E+09) @ 5.00000E02 Hz
calc_del=8.92261E01 corr_app=8.92261E01 est_delay=8.92261E01
final_sint=0.01(sec/sample)
stage 1: LAPLACE A0=6.259322E+08 NZeros= 2 NPoles= 5
Sd=1.369329E+03
stage 2: GAIN Sd=1.000000E+00
stage 3: FIR_SYM_1 H0=1.000000E+00 Ncoeff= 1 SamInt=1.953125E06
Sd=8.388610E+05
stage 4: FIR_SYM_2 H0=1.000000E+00 Ncoeff= 36 SamInt=1.953125E06
Sd=1.000000E+00
stage 5: FIR_SYM_2 H0=1.000000E+00 Ncoeff= 6 SamInt=1.562500E05
Sd=1.000000E+00
stage 6: FIR_SYM_1 H0=1.000000E+00 Ncoeff= 7 SamInt=3.125000E05
Sd=1.000000E+00
stage 7: FIR_SYM_2 H0=1.000000E+00 Ncoeff= 48 SamInt=6.250000E05
Sd=1.000000E+00
stage 8: FIR_SYM_2 H0=1.000000E+00 Ncoeff=126 SamInt=2.500000E04
Sd=1.000000E+00
stage 9: FIR_SYM_1 H0=1.000000E+00 Ncoeff=501 SamInt=5.000000E04
Sd=1.000000E+00
stage 10: FIR_SYM_1 H0=1.000000E+00 Ncoeff=501 SamInt=1.000000E03
Sd=1.000000E+00
stage 11: FIR_SYM_1 H0=1.000000E+00 Ncoeff=501 SamInt=2.000000E03
Sd=1.000000E+00

%
Possibly someone at IRIS can comment on this further. I think the first
gain value is being modified due to a Analog PoleZero.
Brian
savage<at>uri.edu
On Feb 18, 2014, at 4:57 PM, Blaine Bockholt (bbckholt) wrote:
I am attempting to remove the instrument response of some data. I
downloaded the RESPFILE from IRIS and while using the evalresp option of
transfer, I get the following error:
"WARNING (norm_resp): computed and reported sensitivities[ET.CPCT.00.HHE]
differ by more than 5 percent."
I thought the final sensitivity at the end of the file is the product of
all the different gain/sensitivities of each stage. When I calculate it by
hand, I get the sensitivity reported. I am not sure where this error is
coming from, nor I am sure how SAC calculates the sensitivity. Thanks.
Blaine
Here is the command I use
trans from evalresp fname ET.CPCT.resp to none freqlim 0.001 0.002 15 20
_______________________________________________
sachelp mailing list
sachelp<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sachelp
_______________________________________________
sachelp mailing list
sachelp<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sachelp

Thanks for the helpful reply, Philip. I had Mary Templeton looking at it and she came the same conclusion as you. She made a plot to illustrate:
So the recommendation, I take it, is for the frequency of sensitivity, Blockette 58, stage 0, field 5 to be changed to 1.00000E+00.
What I noticed was that the Normalization frequency of stage 1 is in fact set to 1 Hz, so I wonder if this is a product of merging the sensor to a datalogger response and then not seeing a trickledown alteration of the frequency of sensitivity to stage 0? The PDCC tool doesn't handle this, for example, but I do recall having discussions about this and seeing the solution as ambiguous.
So if Blaine edits the RESP file, is that the way to proceed?
Rob
Hi
Responses are at best confusing, but you need to remember that the gain is not just a value, it is a value at a particular frequency.
The last stage (stage zero) is supposed to be the overall gain and should be the product of the gains at each stage, but only if the frequency of each stage is the same. In this case the stage zero gain is +1.25829E+09, but it is given at freq of 5e2. The stage 1 gain is 1.5e3, but at a freq of 1Hz. So to be proper, you must adjust the gain based on the poles and zeros from 1Hz to 5e2 Hz before you multiply. Looking at the response plot here:
http://service.iris.edu/irisws/evalresp/1/query?net=ET&sta=CPCT&loc=00&cha=HHZ&time=20090607T00:00:00&units=def&annotate=true&output=plot
it looks like 5e2 is just barely beyond the flat part of the response, which explains why evalresp says that the stage 1 gain is 1.369329E+03 instead of 1.5e3. It has rolled off just a bit at 5e2 Hz compared to 1Hz which is in the flat part of the response.
To be honest, I think that the mistake in this response is not in the gain numbers, but rather in the frequency reported in the stage zero. It probably should have the frequency in the stage zero as 1Hz instead of 5e3Hz . So, likely in this case the 1.25829E+09 is the gain you want to use even though evalresp complains.
Hope this helps,
Philip
On Thu, Feb 20, 2014 at 1:44 PM, Brian Savage <savage<at>uri.edu> wrote:
Dear Blaine,
This error is generated by evalresp. You should be able to confirm this by running evalresp on your RESP file.
For example
% evalresp CPCT HHE 2010 001 0.001 20 v f RESP.ET.CPCT.HHE.2
<< EVALRESP RESPONSE OUTPUT V3.3.3 >>
WARNING (norm_resp): computed and reported sensitivities differ by more than 5 percent.
Execution continuing.

RESP.ET.CPCT.HHE.2

ET CPCT 00 HHE 2009,001,00:00:00 2011,026,00:00:00
Seed units: Velocity(in)>Counts(out)
computed sens=1.14868E+09 (reported=1.25829E+09) @ 5.00000E02 Hz
calc_del=8.92261E01 corr_app=8.92261E01 est_delay=8.92261E01 final_sint=0.01(sec/sample)
stage 1: LAPLACE A0=6.259322E+08 NZeros= 2 NPoles= 5 Sd=1.369329E+03
stage 2: GAIN Sd=1.000000E+00
stage 3: FIR_SYM_1 H0=1.000000E+00 Ncoeff= 1 SamInt=1.953125E06 Sd=8.388610E+05
stage 4: FIR_SYM_2 H0=1.000000E+00 Ncoeff= 36 SamInt=1.953125E06 Sd=1.000000E+00
stage 5: FIR_SYM_2 H0=1.000000E+00 Ncoeff= 6 SamInt=1.562500E05 Sd=1.000000E+00
stage 6: FIR_SYM_1 H0=1.000000E+00 Ncoeff= 7 SamInt=3.125000E05 Sd=1.000000E+00
stage 7: FIR_SYM_2 H0=1.000000E+00 Ncoeff= 48 SamInt=6.250000E05 Sd=1.000000E+00
stage 8: FIR_SYM_2 H0=1.000000E+00 Ncoeff=126 SamInt=2.500000E04 Sd=1.000000E+00
stage 9: FIR_SYM_1 H0=1.000000E+00 Ncoeff=501 SamInt=5.000000E04 Sd=1.000000E+00
stage 10: FIR_SYM_1 H0=1.000000E+00 Ncoeff=501 SamInt=1.000000E03 Sd=1.000000E+00
stage 11: FIR_SYM_1 H0=1.000000E+00 Ncoeff=501 SamInt=2.000000E03 Sd=1.000000E+00

%
Possibly someone at IRIS can comment on this further. I think the first gain value is being modified due to a Analog PoleZero.
Brian
savage<at>uri.edu
On Feb 18, 2014, at 4:57 PM, Blaine Bockholt (bbckholt) wrote:
I am attempting to remove the instrument response of some data. I downloaded the RESPFILE from IRIS and while using the evalresp option of transfer, I get the following error:
_______________________________________________
"WARNING (norm_resp): computed and reported sensitivities[ET.CPCT.00.HHE] differ by more than 5 percent."
I thought the final sensitivity at the end of the file is the product of all the different gain/sensitivities of each stage. When I calculate it by hand, I get the sensitivity reported. I am not sure where this error is coming from, nor I am sure how SAC calculates the sensitivity. Thanks.
Blaine
Here is the command I use
trans from evalresp fname ET.CPCT.resp to none freqlim 0.001 0.002 15 20
_______________________________________________
sachelp mailing list
sachelp<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sachelp
sachelp mailing list
sachelp<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sachelp
_______________________________________________
sachelp mailing list
sachelp<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sachelp
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