Mike Padgett
For waveform data that downloads using Breq-Fast with Quality=Best, rdseed produces IDEP=Unknown and a type of "Time Series."
For these networks, what are the time series units and have instrument responses been removed?
Is raw data available that could be used to verify calculations?
Mike Padgett
For these networks, what are the time series units and have instrument responses been removed?
Is raw data available that could be used to verify calculations?
Mike Padgett
-
Assuming you are talking about data requested from the IRIS DMC using
Breqfast, no, the instrument response has not been removed. IRIS always
provides the raw data, unless you use their webservices and specifically
request it to remove the instrument response.
Units will most likely be counts (i.e. the integers that the digitizer
spits out). You also need to request the meta-data to know for certain and
to change the time series to units of ground motion (m/s for example).
-Renate
On Wed, Apr 9, 2014 at 8:14 AM, Mike Padgett <mpadgett<at>quantum-earth.com>wrote:
For waveform data that downloads using Breq-Fast with Quality=Best, rdseed
--
produces IDEP=Unknown and a type of "Time Series."
For these networks, what are the time series units and have instrument
responses been removed?
Is raw data available that could be used to verify calculations?
Mike Padgett
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
Renate Hartog
Research Scientist
Pacific Northwest Seismic Network
Department of Earth and Space Sciences
University of Washington
Box 351310
Seattle, WA 98195
Tel. +1-206-685-7079 (office)
-
Is the raw data in each seed file, or must it be requested separately?
And thank you
Mike Padgett
On Apr 9, 2014, at 11:08 AM, Renate Hartog <jrhartog<at>uw.edu> wrote:
Assuming you are talking about data requested from the IRIS DMC using Breqfast, no, the instrument response has not been removed. IRIS always provides the raw data, unless you use their webservices and specifically request it to remove the instrument response.
Units will most likely be counts (i.e. the integers that the digitizer spits out). You also need to request the meta-data to know for certain and to change the time series to units of ground motion (m/s for example).
-Renate
On Wed, Apr 9, 2014 at 8:14 AM, Mike Padgett <mpadgett<at>quantum-earth.com> wrote:
--
For waveform data that downloads using Breq-Fast with Quality=Best, rdseed produces IDEP=Unknown and a type of "Time Series."
For these networks, what are the time series units and have instrument responses been removed?
Is raw data available that could be used to verify calculations?
Mike Padgett
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
Renate Hartog
Research Scientist
Pacific Northwest Seismic Network
Department of Earth and Space Sciences
University of Washington
Box 351310
Seattle, WA 98195
Tel. +1-206-685-7079 (office)
-
The raw data are in the seed file, you extracted them as SAC files. If you
requested a full SEED file, you should also have the meta-data in the SEED
file. Try running rdseed with the following options:
rdseed -f seedfilename -R
You should now have a bunch a RESP-files, at least one for each channel. If
you look at the file with a text editor, you'll see something like this
somewhere in the file:
B053F03 Transfer function type: A
B053F04 Stage sequence number: 1
B053F05 Response in units lookup: M/S - Velocity in Meters
Per Second
This means that the first thing into the chain of
instrument-response-stages (stage sequence number=1) has velocity units
(i.e. this is a velocity response).
You'll see many more Stage sequence numbers, look and you will find one
that has input units of V and output units of COUNTS, the last output units
in the response train are the units of the time series (UNLESS you
requested it in other ways and explicitely asked for the instrument
response to be removed!).
Finally, you will see a stage 0 blockette 58, with an overall sensitivity
(gain). For example:
#
B058F03 Stage sequence number: 0
B058F04 Sensitivity: +6.26224E+04
B058F05 Frequency of sensitivity: +1.00000E+00
B058F06 Number of calibrations: 0
If the original provider of the meta-data specified a "Frequency of
sensitivity" that falls in the frequency range where the instrument
response is relatively flat, you could simple divide your time series by
this number to go from counts to m/s (in this example) and have an estimate
of ground velocity.
More details can be found in the SEED manual
http://www.iris.edu/dms/nodes/dmc/data/formats/#seed , in particular in
Appendix C, but you may also need to consult some textbooks.
To get SAC pole-zero files that you can use to remove instrument response
with SAC, run rdseed as follows:
rdseed -f seedfilename -p
I'd recommend trying out this webservice:
http://service.iris.edu/irisws/timeseries/1/
-Renate
On Wed, Apr 9, 2014 at 9:48 AM, Mike Padgett <mpadgett<at>quantum-earth.com>wrote:
Is the raw data in each seed file, or must it be requested separately?
--
And thank you
Mike Padgett
On Apr 9, 2014, at 11:08 AM, Renate Hartog <jrhartog<at>uw.edu> wrote:
Assuming you are talking about data requested from the IRIS DMC using
Breqfast, no, the instrument response has not been removed. IRIS always
provides the raw data, unless you use their webservices and specifically
request it to remove the instrument response.
Units will most likely be counts (i.e. the integers that the digitizer
spits out). You also need to request the meta-data to know for certain and
to change the time series to units of ground motion (m/s for example).
-Renate
On Wed, Apr 9, 2014 at 8:14 AM, Mike Padgett <mpadgett<at>quantum-earth.com>wrote:
For waveform data that downloads using Breq-Fast with Quality=Best,
--
rdseed produces IDEP=Unknown and a type of "Time Series."
For these networks, what are the time series units and have instrument
responses been removed?
Is raw data available that could be used to verify calculations?
Mike Padgett
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
Renate Hartog
Research Scientist
Pacific Northwest Seismic Network
Department of Earth and Space Sciences
University of Washington
Box 351310
Seattle, WA 98195
Tel. +1-206-685-7079 (office)
Renate Hartog
Research Scientist
Pacific Northwest Seismic Network
Department of Earth and Space Sciences
University of Washington
Box 351310
Seattle, WA 98195
Tel. +1-206-685-7079 (office)
-
Thank you again. The gain as a function of frequency is a big concern.
Mike Padgett
On Apr 9, 2014, at 12:12 PM, Renate Hartog <jrhartog<at>uw.edu> wrote:
The raw data are in the seed file, you extracted them as SAC files. If you requested a full SEED file, you should also have the meta-data in the SEED file. Try running rdseed with the following options:
rdseed -f seedfilename -R
You should now have a bunch a RESP-files, at least one for each channel. If you look at the file with a text editor, you'll see something like this somewhere in the file:
B053F03 Transfer function type: A
B053F04 Stage sequence number: 1
B053F05 Response in units lookup: M/S - Velocity in Meters Per Second
This means that the first thing into the chain of instrument-response-stages (stage sequence number=1) has velocity units (i.e. this is a velocity response).
You'll see many more Stage sequence numbers, look and you will find one that has input units of V and output units of COUNTS, the last output units in the response train are the units of the time series (UNLESS you requested it in other ways and explicitely asked for the instrument response to be removed!).
Finally, you will see a stage 0 blockette 58, with an overall sensitivity (gain). For example:
#
B058F03 Stage sequence number: 0
B058F04 Sensitivity: +6.26224E+04
B058F05 Frequency of sensitivity: +1.00000E+00
B058F06 Number of calibrations: 0
If the original provider of the meta-data specified a "Frequency of sensitivity" that falls in the frequency range where the instrument response is relatively flat, you could simple divide your time series by this number to go from counts to m/s (in this example) and have an estimate of ground velocity.
More details can be found in the SEED manual http://www.iris.edu/dms/nodes/dmc/data/formats/#seed , in particular in Appendix C, but you may also need to consult some textbooks.
To get SAC pole-zero files that you can use to remove instrument response with SAC, run rdseed as follows:
rdseed -f seedfilename -p
I'd recommend trying out this webservice: http://service.iris.edu/irisws/timeseries/1/
-Renate
On Wed, Apr 9, 2014 at 9:48 AM, Mike Padgett <mpadgett<at>quantum-earth.com> wrote:
--
Is the raw data in each seed file, or must it be requested separately?
And thank you
Mike Padgett
On Apr 9, 2014, at 11:08 AM, Renate Hartog <jrhartog<at>uw.edu> wrote:
Assuming you are talking about data requested from the IRIS DMC using Breqfast, no, the instrument response has not been removed. IRIS always provides the raw data, unless you use their webservices and specifically request it to remove the instrument response.
Units will most likely be counts (i.e. the integers that the digitizer spits out). You also need to request the meta-data to know for certain and to change the time series to units of ground motion (m/s for example).
-Renate
On Wed, Apr 9, 2014 at 8:14 AM, Mike Padgett <mpadgett<at>quantum-earth.com> wrote:
--
For waveform data that downloads using Breq-Fast with Quality=Best, rdseed produces IDEP=Unknown and a type of "Time Series."
For these networks, what are the time series units and have instrument responses been removed?
Is raw data available that could be used to verify calculations?
Mike Padgett
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
Renate Hartog
Research Scientist
Pacific Northwest Seismic Network
Department of Earth and Space Sciences
University of Washington
Box 351310
Seattle, WA 98195
Tel. +1-206-685-7079 (office)
Renate Hartog
Research Scientist
Pacific Northwest Seismic Network
Department of Earth and Space Sciences
University of Washington
Box 351310
Seattle, WA 98195
Tel. +1-206-685-7079 (office)
-
Hi Mike,
The units of the recording instrument and the scaling factor (sensitivity) at a specific frequency are often available in so-called annotated SAC Poles and Zeros files in addition to the RESP files. Recent versions of rdseed will create SAC PZ files with them (using the -p option as suggested below) and we have a web service that returns such annotated SAC PZs:
http://service.iris.edu/irisws/sacpz/1/
for example:
http://service.iris.edu/irisws/sacpz/1/query?net=IU&sta=ANMO&loc=00&cha=BHZ&time=2008-11-25T13:05:00.010
Converting the data to Earth units (using SAC PZs or RESP files) through a frequency range beyond the flat portion of response is something others on this mailing list can help with. As Renate noted below, the IRIS DMC offers a web service that performs this function as well (http://service.iris.edu/irisws/timeseries/1/), effectively doing the same thing as the sac software. Feel free to contact me directly, or use the webservice mailing list, if you have questions about that service.
Touching on an earlier topic, SEED data qualities are generally not related to units of the data. The quality control implied by these codes varies by network operator and is generally things like adding more data to the set, making smallish time corrections, etc. I know of no cases where it is used to denote time series processed data versus, mostly it is a better, more complete version of the initial raw data. For the vast majority of IRIS DMC users they should not be requesting any specific quality of data, but just let the default “Best” return M quality data. The short story behind the use of the M quality code can be read here:
http://www.iris.edu/dms/newsletter/vol12/no3/m-quality-data/
regards,
Chad
On Apr 9, 2014, at 10:47 AM, Mike Padgett <mpadgett<at>quantum-earth.com> wrote:
Thank you again. The gain as a function of frequency is a big concern.
Mike Padgett
On Apr 9, 2014, at 12:12 PM, Renate Hartog <jrhartog<at>uw.edu> wrote:
The raw data are in the seed file, you extracted them as SAC files. If you requested a full SEED file, you should also have the meta-data in the SEED file. Try running rdseed with the following options:
_______________________________________________
rdseed -f seedfilename -R
You should now have a bunch a RESP-files, at least one for each channel. If you look at the file with a text editor, you'll see something like this somewhere in the file:
B053F03 Transfer function type: A
B053F04 Stage sequence number: 1
B053F05 Response in units lookup: M/S - Velocity in Meters Per Second
This means that the first thing into the chain of instrument-response-stages (stage sequence number=1) has velocity units (i.e. this is a velocity response).
You'll see many more Stage sequence numbers, look and you will find one that has input units of V and output units of COUNTS, the last output units in the response train are the units of the time series (UNLESS you requested it in other ways and explicitely asked for the instrument response to be removed!).
Finally, you will see a stage 0 blockette 58, with an overall sensitivity (gain). For example:
#
B058F03 Stage sequence number: 0
B058F04 Sensitivity: +6.26224E+04
B058F05 Frequency of sensitivity: +1.00000E+00
B058F06 Number of calibrations: 0
If the original provider of the meta-data specified a "Frequency of sensitivity" that falls in the frequency range where the instrument response is relatively flat, you could simple divide your time series by this number to go from counts to m/s (in this example) and have an estimate of ground velocity.
More details can be found in the SEED manual http://www.iris.edu/dms/nodes/dmc/data/formats/#seed , in particular in Appendix C, but you may also need to consult some textbooks.
To get SAC pole-zero files that you can use to remove instrument response with SAC, run rdseed as follows:
rdseed -f seedfilename -p
I'd recommend trying out this webservice: http://service.iris.edu/irisws/timeseries/1/
-Renate
On Wed, Apr 9, 2014 at 9:48 AM, Mike Padgett <mpadgett<at>quantum-earth.com> wrote:
Is the raw data in each seed file, or must it be requested separately?
And thank you
Mike Padgett
On Apr 9, 2014, at 11:08 AM, Renate Hartog <jrhartog<at>uw.edu> wrote:
Assuming you are talking about data requested from the IRIS DMC using Breqfast, no, the instrument response has not been removed. IRIS always provides the raw data, unless you use their webservices and specifically request it to remove the instrument response.
--
Units will most likely be counts (i.e. the integers that the digitizer spits out). You also need to request the meta-data to know for certain and to change the time series to units of ground motion (m/s for example).
-Renate
On Wed, Apr 9, 2014 at 8:14 AM, Mike Padgett <mpadgett<at>quantum-earth.com> wrote:
For waveform data that downloads using Breq-Fast with Quality=Best, rdseed produces IDEP=Unknown and a type of "Time Series."
For these networks, what are the time series units and have instrument responses been removed?
Is raw data available that could be used to verify calculations?
Mike Padgett
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
--
Renate Hartog
Research Scientist
Pacific Northwest Seismic Network
Department of Earth and Space Sciences
University of Washington
Box 351310
Seattle, WA 98195
Tel. +1-206-685-7079 (office)
Renate Hartog
Research Scientist
Pacific Northwest Seismic Network
Department of Earth and Space Sciences
University of Washington
Box 351310
Seattle, WA 98195
Tel. +1-206-685-7079 (office)
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
-
Renate and Chad,
As I understand your responses, the Breq-Fast quality of "Best" will be
denote as a ".M.SAC" file coming from rdseed. In the file from rdseed, the
data will be called a "Time Series" file with IDEP=UNKNOWN, which means the
units are most likely "Counts" and have no instrument response removed.
Also, the "Best" quality data is considered to be the preferred starting
point for all archived network data.
I'm sure that I'll have more questions, but again, thanks for the help,
Mike Padgett
From: Chad Trabant [chad<at>iris.washington.edu]
Sent: Wednesday, April 09, 2014 1:39 PM
To: Mike Padgett
Cc: Renate Hartog; sac-help
Subject: Re: [SAC-HELP] Time series from CI, IU and II with Quality=Best
Hi Mike,
The units of the recording instrument and the scaling factor (sensitivity)
at a specific frequency are often available in so-called annotated SAC Poles
and Zeros files in addition to the RESP files. Recent versions of rdseed
will create SAC PZ files with them (using the -p option as suggested below)
and we have a web service that returns such annotated SAC PZs:
http://service.iris.edu/irisws/sacpz/1/
for example:
http://service.iris.edu/irisws/sacpz/1/query?net=IU
http://service.iris.edu/irisws/sacpz/1/query?net=IU&sta=ANMO&loc=00&cha=BHZ
&time=2008-11-25T13:05:00.010>
&sta=ANMO&loc=00&cha=BHZ&time=2008-11-25T13:05:00.010
Converting the data to Earth units (using SAC PZs or RESP files) through a
frequency range beyond the flat portion of response is something others on
this mailing list can help with. As Renate noted below, the IRIS DMC offers
a web service that performs this function as well
(http://service.iris.edu/irisws/timeseries/1/), effectively doing the same
thing as the sac software. Feel free to contact me directly, or use the
webservice mailing list, if you have questions about that service.
Touching on an earlier topic, SEED data qualities are generally not related
to units of the data. The quality control implied by these codes varies by
network operator and is generally things like adding more data to the set,
making smallish time corrections, etc. I know of no cases where it is used
to denote time series processed data versus, mostly it is a better, more
complete version of the initial raw data. For the vast majority of IRIS DMC
users they should not be requesting any specific quality of data, but just
let the default "Best" return M quality data. The short story behind the
use of the M quality code can be read here:
http://www.iris.edu/dms/newsletter/vol12/no3/m-quality-data/
regards,
Chad
On Apr 9, 2014, at 10:47 AM, Mike Padgett <mpadgett<at>quantum-earth.com
<mpadgett<at>quantum-earth.com> > wrote:
Thank you again. The gain as a function of frequency is a big concern.
Mike Padgett
On Apr 9, 2014, at 12:12 PM, Renate Hartog <jrhartog<at>uw.edu
<jrhartog<at>uw.edu> > wrote:
The raw data are in the seed file, you extracted them as SAC files. If you
requested a full SEED file, you should also have the meta-data in the SEED
file. Try running rdseed with the following options:
rdseed -f seedfilename -R
You should now have a bunch a RESP-files, at least one for each channel. If
you look at the file with a text editor, you'll see something like this
somewhere in the file:
B053F03 Transfer function type: A
B053F04 Stage sequence number: 1
B053F05 Response in units lookup: M/S - Velocity in Meters
Per Second
This means that the first thing into the chain of instrument-response-stages
(stage sequence number=1) has velocity units (i.e. this is a velocity
response).
You'll see many more Stage sequence numbers, look and you will find one that
has input units of V and output units of COUNTS, the last output units in
the response train are the units of the time series (UNLESS you requested it
in other ways and explicitely asked for the instrument response to be
removed!).
Finally, you will see a stage 0 blockette 58, with an overall sensitivity
(gain). For example:
#
B058F03 Stage sequence number: 0
B058F04 Sensitivity: +6.26224E+04
B058F05 Frequency of sensitivity: +1.00000E+00
B058F06 Number of calibrations: 0
If the original provider of the meta-data specified a "Frequency of
sensitivity" that falls in the frequency range where the instrument response
is relatively flat, you could simple divide your time series by this number
to go from counts to m/s (in this example) and have an estimate of ground
velocity.
More details can be found in the SEED manual
http://www.iris.edu/dms/nodes/dmc/data/formats/#seed , in particular in
Appendix C, but you may also need to consult some textbooks.
To get SAC pole-zero files that you can use to remove instrument response
with SAC, run rdseed as follows:
rdseed -f seedfilename -p
I'd recommend trying out this webservice:
http://service.iris.edu/irisws/timeseries/1/
-Renate
On Wed, Apr 9, 2014 at 9:48 AM, Mike Padgett <mpadgett<at>quantum-earth.com
<mpadgett<at>quantum-earth.com> > wrote:
Is the raw data in each seed file, or must it be requested separately?
And thank you
Mike Padgett
On Apr 9, 2014, at 11:08 AM, Renate Hartog <jrhartog<at>uw.edu
<jrhartog<at>uw.edu> > wrote:
Assuming you are talking about data requested from the IRIS DMC using
Breqfast, no, the instrument response has not been removed. IRIS always
provides the raw data, unless you use their webservices and specifically
request it to remove the instrument response.
Units will most likely be counts (i.e. the integers that the digitizer spits
out). You also need to request the meta-data to know for certain and to
change the time series to units of ground motion (m/s for example).
-Renate
On Wed, Apr 9, 2014 at 8:14 AM, Mike Padgett <mpadgett<at>quantum-earth.com
<mpadgett<at>quantum-earth.com> > wrote:
For waveform data that downloads using Breq-Fast with Quality=Best, rdseed
produces IDEP=Unknown and a type of "Time Series."
For these networks, what are the time series units and have instrument
responses been removed?
Is raw data available that could be used to verify calculations?
Mike Padgett
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu <sac-help<at>iris.washington.edu>
http://www.iris.washington.edu/mailman/listinfo/sac-help
--
Renate Hartog
Research Scientist
Pacific Northwest Seismic Network
Department of Earth and Space Sciences
University of Washington
Box 351310
Seattle, WA 98195
Tel. +1-206-685-7079 <tel:%2B1-206-685-7079> (office)
--
Renate Hartog
Research Scientist
Pacific Northwest Seismic Network
Department of Earth and Space Sciences
University of Washington
Box 351310
Seattle, WA 98195
Tel. +1-206-685-7079 (office)
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu <sac-help<at>iris.washington.edu>
http://www.iris.washington.edu/mailman/listinfo/sac-help
-
Hi Mike,
Yes on all counts, as long as you are getting data from the IRIS DMC (the notion of "Best" resulting in M quality code is a DMC-specific thing as far as I know).
Chad
----- Original Message -----
From: "Mike Padgett" <mpadgett<at>quantum-earth.com>
To: "Chad Trabant" <chad<at>iris.washington.edu>
Cc: "Renate Hartog" <jrhartog<at>uw.edu>, "sac-help" <sac-help<at>iris.washington.edu>
Sent: Wednesday, April 9, 2014 6:54:11 PM
Subject: RE: [SAC-HELP] Time series from CI, IU and II with Quality=Best
Renate and Chad,
As I understand your responses, the Breq-Fast quality of “Best” will be denote as a “.M.SAC” file coming from rdseed. In the file from rdseed, the data will be called a “Time Series” file with IDEP=UNKNOWN, which means the units are most likely “Counts” and have no instrument response removed.
Also, the “Best” quality data is considered to be the preferred starting point for all archived network data.
I’m sure that I’ll have more questions, but again, thanks for the help,
Mike Padgett
From: Chad Trabant [chad<at>iris.washington.edu]
Sent: Wednesday, April 09, 2014 1:39 PM
To: Mike Padgett
Cc: Renate Hartog; sac-help
Subject: Re: [SAC-HELP] Time series from CI, IU and II with Quality=Best
Hi Mike,
The units of the recording instrument and the scaling factor (sensitivity) at a specific frequency are often available in so-called annotated SAC Poles and Zeros files in addition to the RESP files. Recent versions of rdseed will create SAC PZ files with them (using the -p option as suggested below) and we have a web service that returns such annotated SAC PZs:
http://service.iris.edu/irisws/sacpz/1/
for example:
http://service.iris.edu/irisws/sacpz/1/query?net=IU&sta=ANMO&loc=00&cha=BHZ&time=2008-11-25T13:05:00.010
Converting the data to Earth units (using SAC PZs or RESP files) through a frequency range beyond the flat portion of response is something others on this mailing list can help with. As Renate noted below, the IRIS DMC offers a web service that performs this function as well ( http://service.iris.edu/irisws/timeseries/1/ ), effectively doing the same thing as the sac software. Feel free to contact me directly, or use the webservice mailing list, if you have questions about that service.
Touching on an earlier topic, SEED data qualities are generally not related to units of the data. The quality control implied by these codes varies by network operator and is generally things like adding more data to the set, making smallish time corrections, etc. I know of no cases where it is used to denote time series processed data versus, mostly it is a better, more complete version of the initial raw data. For the vast majority of IRIS DMC users they should not be requesting any specific quality of data, but just let the default “Best” return M quality data. The short story behind the use of the M quality code can be read here:
http://www.iris.edu/dms/newsletter/vol12/no3/m-quality-data/
regards,
Chad
On Apr 9, 2014, at 10:47 AM, Mike Padgett < mpadgett<at>quantum-earth.com > wrote:
Thank you again. The gain as a function of frequency is a big concern.
Mike Padgett
On Apr 9, 2014, at 12:12 PM, Renate Hartog < jrhartog<at>uw.edu > wrote:
The raw data are in the seed file, you extracted them as SAC files. If you requested a full SEED file, you should also have the meta-data in the SEED file. Try running rdseed with the following options:
rdseed -f seedfilename -R
You should now have a bunch a RESP-files, at least one for each channel. If you look at the file with a text editor, you'll see something like this somewhere in the file:
B053F03 Transfer function type: A
B053F04 Stage sequence number: 1
B053F05 Response in units lookup: M/S - Velocity in Meters Per Second
This means that the first thing into the chain of instrument-response-stages (stage sequence number=1) has velocity units (i.e. this is a velocity response).
You'll see many more Stage sequence numbers, look and you will find one that has input units of V and output units of COUNTS, the last output units in the response train are the units of the time series (UNLESS you requested it in other ways and explicitely asked for the instrument response to be removed!).
Finally, you will see a stage 0 blockette 58, with an overall sensitivity (gain). For example:
#
B058F03 Stage sequence number: 0
B058F04 Sensitivity: +6.26224E+04
B058F05 Frequency of sensitivity: +1.00000E+00
B058F06 Number of calibrations: 0
If the original provider of the meta-data specified a "Frequency of sensitivity" that falls in the frequency range where the instrument response is relatively flat, you could simple divide your time series by this number to go from counts to m/s (in this example) and have an estimate of ground velocity.
More details can be found in the SEED manual http://www.iris.edu/dms/nodes/dmc/data/formats/#seed , in particular in Appendix C, but you may also need to consult some textbooks.
To get SAC pole-zero files that you can use to remove instrument response with SAC, run rdseed as follows:
rdseed -f seedfilename -p
I'd recommend trying out this webservice: http://service.iris.edu/irisws/timeseries/1/
-Renate
On Wed, Apr 9, 2014 at 9:48 AM, Mike Padgett < mpadgett<at>quantum-earth.com > wrote:
Is the raw data in each seed file, or must it be requested separately?
And thank you
Mike Padgett
On Apr 9, 2014, at 11:08 AM, Renate Hartog < jrhartog<at>uw.edu > wrote:
Assuming you are talking about data requested from the IRIS DMC using Breqfast, no, the instrument response has not been removed. IRIS always provides the raw data, unless you use their webservices and specifically request it to remove the instrument response.
Units will most likely be counts (i.e. the integers that the digitizer spits out). You also need to request the meta-data to know for certain and to change the time series to units of ground motion (m/s for example).
-Renate
On Wed, Apr 9, 2014 at 8:14 AM, Mike Padgett < mpadgett<at>quantum-earth.com > wrote:
For waveform data that downloads using Breq-Fast with Quality=Best, rdseed produces IDEP=Unknown and a type of "Time Series."
For these networks, what are the time series units and have instrument responses been removed?
Is raw data available that could be used to verify calculations?
Mike Padgett
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--
Renate Hartog
Research Scientist
Pacific Northwest Seismic Network
Department of Earth and Space Sciences
University of Washington
Box 351310
Seattle, WA 98195
Tel. +1-206-685-7079 (office)
--
Renate Hartog
Research Scientist
Pacific Northwest Seismic Network
Department of Earth and Space Sciences
University of Washington
Box 351310
Seattle, WA 98195
Tel. +1-206-685-7079 (office)
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
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Renate Hartog
Chad Trabant
