Dear Mr. or Mrs.,
I am concerned about the reliability of units before and after the instrument correction.I followed this exact procedure:1)downloaded GDSN BB teleseismic waveforms of a 6.9 earthquake from Wilber3(IRIS) in a SEED file2)converted to SAC files with rdseed program and read them on SAC3)checked the header : IDEP=UNKNOWN4)used the sac command 'transfer' to remove the instrument using the extracted(from rdseed) PZfiles:transfer from polezero subtype %PZfile to vel freq 0.01 0.02 50 60
5)checked again the header : IDEP= VELOCITY (NM/SEC).The shape of the waveform didn't change at all, so the 'VELOCITY' part of the header is correct.
The teleseismic amplitudes changed from *10^5 to *10^(-5) and the earthquake is of Mw=6.9.
Are the NM/SEC units the correct ones?Is there a chance that the units are M/SEC?Which is the safest way to remove the instrument?
The subject of 'reliability of UNITS in SAC headers' is of major significance, especially to new researchers, since various mistakes can easily be done. Any useful reply or advice is greatly appreciated.
Thank you in advance!E. Tsakiroudi
I am concerned about the reliability of units before and after the instrument correction.I followed this exact procedure:1)downloaded GDSN BB teleseismic waveforms of a 6.9 earthquake from Wilber3(IRIS) in a SEED file2)converted to SAC files with rdseed program and read them on SAC3)checked the header : IDEP=UNKNOWN4)used the sac command 'transfer' to remove the instrument using the extracted(from rdseed) PZfiles:transfer from polezero subtype %PZfile to vel freq 0.01 0.02 50 60
5)checked again the header : IDEP= VELOCITY (NM/SEC).The shape of the waveform didn't change at all, so the 'VELOCITY' part of the header is correct.
The teleseismic amplitudes changed from *10^5 to *10^(-5) and the earthquake is of Mw=6.9.
Are the NM/SEC units the correct ones?Is there a chance that the units are M/SEC?Which is the safest way to remove the instrument?
The subject of 'reliability of UNITS in SAC headers' is of major significance, especially to new researchers, since various mistakes can easily be done. Any useful reply or advice is greatly appreciated.
Thank you in advance!E. Tsakiroudi
-
Hi Eva,
The transfer manual say:
For displacements, the SAC convention is nm, while RDSEED RESP files use meters. The EVALRESP option in TRANSFER corrects the output to the SAC convention. For other options (FAP, PZ) it may be ncessary to change the units.
See below
On Apr 23, 2015, at 14:43, Eva Tsakiroudi <evatsakir<at>yahoo.com> wrote:
OK
Dear Mr. or Mrs.,
I am concerned about the reliability of units before and after the instrument correction.
I followed this exact procedure:
1)downloaded GDSN BB teleseismic waveforms of a 6.9 earthquake from Wilber3(IRIS) in a SEED file
2)converted to SAC files with rdseed program and read them on SAC
OK
3)checked the header : IDEP=UNKNOWN
?? i do not know the reason.
4)used the sac command 'transfer' to remove the instrument using the extracted(from rdseed) PZfiles:
OK, but only for curiosity, the low pass filter (fc 50 60), have you signals sampled at least at 120 Hz or greater?
transfer from polezero subtype %PZfile to vel freq 0.01 0.02 50 60
5)checked again the header : IDEP= VELOCITY (NM/SEC).
OK, in your transfer command you pass to velocity.
The shape of the waveform didn't change at all, so the 'VELOCITY' part of the header is correct.
Here, you must to multiply for 10^9 to obtain nm, in your case velocity (nm/s).
The teleseismic amplitudes changed from *10^5 to *10^(-5) and the earthquake is of Mw=6.9.
Are the NM/SEC units the correct ones?
Use the evalresp option in transfer to correct the units.
Is there a chance that the units are M/SEC?
Which is the safest way to remove the instrument?
The subject of 'reliability of UNITS in SAC headers' is of major significance, especially to new researchers, since various mistakes can easily be done. Any useful reply or advice is greatly appreciated.
I agree.
Thank you in advance!
HOPE TO HELP,
E. Tsakiroudi
Milton
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
-
Dear Mr. Plasencia,Thank you so much for your reply!
So, you're saying that if I do this procedure on GDSN BB data, the output is VELOCITY in M/SEC. And that if I used the 'evalresp' option, the output would be VELOCITY in NM/SEC ('sac convention'). Is that right?
Also, is there a way for the IDEP of the (downloaded by IRIS and converted to .SAC) data, not to be UNKNOWN?
E. Tsakiroudi
Στις 4:35 μ.μ. Πέμπτη, 23 Απριλίου 2015, ο/η Milton Plasencia <mplasencia<at>inogs.it> έγραψε:
Hi Eva,
The transfer manual say:
For displacements, the SAC convention is nm, while RDSEED RESP files use meters. The EVALRESP option in TRANSFER corrects the output to the SAC convention. For other options (FAP, PZ) it may be ncessary to change the units.
See below
On Apr 23, 2015, at 14:43, Eva Tsakiroudi <evatsakir<at>yahoo.com> wrote:
Dear Mr. or Mrs.,
I am concerned about the reliability of units before and after the instrument correction.I followed this exact procedure:1)downloaded GDSN BB teleseismic waveforms of a 6.9 earthquake from Wilber3(IRIS) in a SEED file
OK
2)converted to SAC files with rdseed program and read them on SAC
OK
3)checked the header : IDEP=UNKNOWN
?? i do not know the reason.
4)used the sac command 'transfer' to remove the instrument using the extracted(from rdseed) PZfiles:transfer from polezero subtype %PZfile to vel freq 0.01 0.02 50 60
OK, but only for curiosity, the low pass filter (fc 50 60), have you signals sampled at least at 120 Hz or greater?
5)checked again the header : IDEP= VELOCITY (NM/SEC).
OK, in your transfer command you pass to velocity.
The shape of the waveform didn't change at all, so the 'VELOCITY' part of the header is correct.
The teleseismic amplitudes changed from *10^5 to *10^(-5) and the earthquake is of Mw=6.9.
Here, you must to multiply for 10^9 to obtain nm, in your case velocity (nm/s).
Are the NM/SEC units the correct ones?Is there a chance that the units are M/SEC?Which is the safest way to remove the instrument?
Use the evalresp option in transfer to correct the units.
The subject of 'reliability of UNITS in SAC headers' is of major significance, especially to new researchers, since various mistakes can easily be done. Any useful reply or advice is greatly appreciated.
I agree.
Thank you in advance!
HOPE TO HELP,
E. Tsakiroudi
Milton
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
-
Milton Plasencia
2015-04-23 23:01:17Hi,
On Apr 23, 2015, at 15:57, Eva Tsakiroudi <evatsakir<at>yahoo.com> wrote:
Yes
Dear Mr. Plasencia,
Thank you so much for your reply!
So, you're saying that if I do this procedure on GDSN BB data, the output is VELOCITY in M/SEC. And that if I used the 'evalresp' option, the output would be VELOCITY in NM/SEC ('sac convention'). Is that right?
Also, is there a way for the IDEP of the (downloaded by IRIS and converted to .SAC) data, not to be UNKNOWN?
I think yes, but no depend of me...
E. Tsakiroudi
M.
Cheers,
Στις 4:35 μ.μ. Πέμπτη, 23 Απριλίου 2015, ο/η Milton Plasencia <mplasencia<at>inogs.it> έγραψε:
Hi Eva,
The transfer manual say:
For displacements, the SAC convention is nm, while RDSEED RESP files use meters. The EVALRESP option in TRANSFER corrects the output to the SAC convention. For other options (FAP, PZ) it may be ncessary to change the units.
See below
On Apr 23, 2015, at 14:43, Eva Tsakiroudi <evatsakir<at>yahoo.com <evatsakir<at>yahoo.com>> wrote:
OK
Dear Mr. or Mrs.,
I am concerned about the reliability of units before and after the instrument correction.
I followed this exact procedure:
1)downloaded GDSN BB teleseismic waveforms of a 6.9 earthquake from Wilber3(IRIS) in a SEED file
2)converted to SAC files with rdseed program and read them on SAC
OK
3)checked the header : IDEP=UNKNOWN
?? i do not know the reason.
4)used the sac command 'transfer' to remove the instrument using the extracted(from rdseed) PZfiles:
OK, but only for curiosity, the low pass filter (fc 50 60), have you signals sampled at least at 120 Hz or greater?
transfer from polezero subtype %PZfile to vel freq 0.01 0.02 50 60
5)checked again the header : IDEP= VELOCITY (NM/SEC).
OK, in your transfer command you pass to velocity.
The shape of the waveform didn't change at all, so the 'VELOCITY' part of the header is correct.
Here, you must to multiply for 10^9 to obtain nm, in your case velocity (nm/s).
The teleseismic amplitudes changed from *10^5 to *10^(-5) and the earthquake is of Mw=6.9.
Are the NM/SEC units the correct ones?
Use the evalresp option in transfer to correct the units.
Is there a chance that the units are M/SEC?
Which is the safest way to remove the instrument?
The subject of 'reliability of UNITS in SAC headers' is of major significance, especially to new researchers, since various mistakes can easily be done. Any useful reply or advice is greatly appreciated.
I agree.
Thank you in advance!
HOPE TO HELP,
E. Tsakiroudi
Milton
_______________________________________________
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 Eva,
A point of clarity: I think when using the evalresp option, the units of length (meters, centimeters, nanometers, ...) are whatever is in the RESP file. For the majority of broadband seismic metadata in SEED the length unit is meters, so the assumption is usually good but keep that in mind.
Regarding the setting of IDEP on data you receive from IRIS: most raw seismic data is recorded and archived in units of digital counts, there is no IDEP setting for this. Converting these raw digital counts to Earth units in the general case is non trivial and the method chosen might depend on the study being conducted. We do have a web service at the DMC that performs two different kinds of restitution (deconvolution and scaling): http://service.iris.edu/irisws/timeseries/1/. This service returns a single seismogram and the processing is done on the fly. But even then the IDEP is not set as the length units are again whatever is documented in the RESP and there is not a general enough way to express that variation in IDEP allowed values.
regards,
Chad
On Apr 23, 2015, at 7:01 AM, Milton Plasencia <mplasencia<at>inogs.it> wrote:
Hi,
On Apr 23, 2015, at 15:57, Eva Tsakiroudi <evatsakir<at>yahoo.com <evatsakir<at>yahoo.com>> wrote:
Yes
Dear Mr. Plasencia,
Thank you so much for your reply!
So, you're saying that if I do this procedure on GDSN BB data, the output is VELOCITY in M/SEC. And that if I used the 'evalresp' option, the output would be VELOCITY in NM/SEC ('sac convention'). Is that right?
Also, is there a way for the IDEP of the (downloaded by IRIS and converted to .SAC) data, not to be UNKNOWN?
I think yes, but no depend of me...
E. Tsakiroudi
M.
Cheers,
Στις 4:35 μ.μ. Πέμπτη, 23 Απριλίου 2015, ο/η Milton Plasencia <mplasencia<at>inogs.it <mplasencia<at>inogs.it>> έγραψε:
_______________________________________________
Hi Eva,
The transfer manual say:
For displacements, the SAC convention is nm, while RDSEED RESP files use meters. The EVALRESP option in TRANSFER corrects the output to the SAC convention. For other options (FAP, PZ) it may be ncessary to change the units.
See below
On Apr 23, 2015, at 14:43, Eva Tsakiroudi <evatsakir<at>yahoo.com <evatsakir<at>yahoo.com>> wrote:
OK
Dear Mr. or Mrs.,
I am concerned about the reliability of units before and after the instrument correction.
I followed this exact procedure:
1)downloaded GDSN BB teleseismic waveforms of a 6.9 earthquake from Wilber3(IRIS) in a SEED file
2)converted to SAC files with rdseed program and read them on SAC
OK
3)checked the header : IDEP=UNKNOWN
?? i do not know the reason.
4)used the sac command 'transfer' to remove the instrument using the extracted(from rdseed) PZfiles:
OK, but only for curiosity, the low pass filter (fc 50 60), have you signals sampled at least at 120 Hz or greater?
transfer from polezero subtype %PZfile to vel freq 0.01 0.02 50 60
5)checked again the header : IDEP= VELOCITY (NM/SEC).
OK, in your transfer command you pass to velocity.
The shape of the waveform didn't change at all, so the 'VELOCITY' part of the header is correct.
Here, you must to multiply for 10^9 to obtain nm, in your case velocity (nm/s).
The teleseismic amplitudes changed from *10^5 to *10^(-5) and the earthquake is of Mw=6.9.
Are the NM/SEC units the correct ones?
Use the evalresp option in transfer to correct the units.
Is there a chance that the units are M/SEC?
Which is the safest way to remove the instrument?
The subject of 'reliability of UNITS in SAC headers' is of major significance, especially to new researchers, since various mistakes can easily be done. Any useful reply or advice is greatly appreciated.
I agree.
Thank you in advance!
HOPE TO HELP,
E. Tsakiroudi
Milton
_______________________________________________
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
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
-
E. Tsakiroudi
2015-04-24 19:27:22Dear Mr. Trabant and Mr. Plasencia,
Thank you so much for your replies!
But, in order to make a final conclusion, so that everyone could understand it, I would be greatful if, someone of you, could confirm the following:
When we remove the instrument from a raw waveform, with the 'tranfer-polezero' way or the 'evalresp' way in SAC, the output units are the ones displayed in the PZfile or the RESPfile, respectively, as follows:
PZ_FILE EXAMPLE:
* Input Units : METERS
* Output Units : COUNTS
RESP_FILE EXAMPLE:
B053F05 Response in units lookup: M/S - Velocity in Meters Per Second
B053F06 Response out units lookup: V - Volts
In this example, the OUTPUT units are in METERS/SEC, disregarding the sac header 'IDEP' which might turn into 'NM/SEC', due to SAC conventions.
Is that correct?
Also, I have noticed that the 'RESP' file shows the velocity response and the 'PZfile' shows the displacement response.Does this mean that I have to use only velocity input or only displacement input waveforms, respectively, in each way?Could I use a displacement input, and remove the instrument with a RESPfile(velocity response)?
All these subjects remain unclear for all the new researchers, so we truly appreciate your replies!Have a nice day!
E. Tsakiroudi
Στις 9:13 μ.μ. Πέμπτη, 23 Απριλίου 2015, ο/η Chad Trabant <chad<at>iris.washington.edu> έγραψε:
Hi Eva,
A point of clarity: I think when using the evalresp option, the units of length (meters, centimeters, nanometers, ...) are whatever is in the RESP file. For the majority of broadband seismic metadata in SEED the length unit is meters, so the assumption is usually good but keep that in mind.
Regarding the setting of IDEP on data you receive from IRIS: most raw seismic data is recorded and archived in units of digital counts, there is no IDEP setting for this. Converting these raw digital counts to Earth units in the general case is non trivial and the method chosen might depend on the study being conducted. We do have a web service at the DMC that performs two different kinds of restitution (deconvolution and scaling): http://service.iris.edu/irisws/timeseries/1/. This service returns a single seismogram and the processing is done on the fly. But even then the IDEP is not set as the length units are again whatever is documented in the RESP and there is not a general enough way to express that variation in IDEP allowed values.
regards,Chad
On Apr 23, 2015, at 7:01 AM, Milton Plasencia <mplasencia<at>inogs.it> wrote:
Hi,
On Apr 23, 2015, at 15:57, Eva Tsakiroudi <evatsakir<at>yahoo.com> wrote:
Dear Mr. Plasencia,Thank you so much for your reply!
So, you're saying that if I do this procedure on GDSN BB data, the output is VELOCITY in M/SEC. And that if I used the 'evalresp' option, the output would be VELOCITY in NM/SEC ('sac convention'). Is that right?
Yes
Also, is there a way for the IDEP of the (downloaded by IRIS and converted to .SAC) data, not to be UNKNOWN?
I think yes, but no depend of me...
E. Tsakiroudi
Cheers,
M.
Στις 4:35 μ.μ. Πέμπτη, 23 Απριλίου 2015, ο/η Milton Plasencia <mplasencia<at>inogs.it> έγραψε:
Hi Eva,
The transfer manual say:
For displacements, the SAC convention is nm, while RDSEED RESP files use meters. The EVALRESP option in TRANSFER corrects the output to the SAC convention. For other options (FAP, PZ) it may be ncessary to change the units.
See below
On Apr 23, 2015, at 14:43, Eva Tsakiroudi <evatsakir<at>yahoo.com> wrote:
Dear Mr. or Mrs.,
I am concerned about the reliability of units before and after the instrument correction.I followed this exact procedure:1)downloaded GDSN BB teleseismic waveforms of a 6.9 earthquake from Wilber3(IRIS) in a SEED file
OK
2)converted to SAC files with rdseed program and read them on SAC
OK
3)checked the header : IDEP=UNKNOWN
?? i do not know the reason.
4)used the sac command 'transfer' to remove the instrument using the extracted(from rdseed) PZfiles:transfer from polezero subtype %PZfile to vel freq 0.01 0.02 50 60
OK, but only for curiosity, the low pass filter (fc 50 60), have you signals sampled at least at 120 Hz or greater?
5)checked again the header : IDEP= VELOCITY (NM/SEC).
OK, in your transfer command you pass to velocity.
The shape of the waveform didn't change at all, so the 'VELOCITY' part of the header is correct.
The teleseismic amplitudes changed from *10^5 to *10^(-5) and the earthquake is of Mw=6.9.
Here, you must to multiply for 10^9 to obtain nm, in your case velocity (nm/s).
Are the NM/SEC units the correct ones?Is there a chance that the units are M/SEC?Which is the safest way to remove the instrument?
Use the evalresp option in transfer to correct the units.
The subject of 'reliability of UNITS in SAC headers' is of major significance, especially to new researchers, since various mistakes can easily be done. Any useful reply or advice is greatly appreciated.
I agree.
Thank you in advance!
HOPE TO HELP,
E. Tsakiroudi
Milton
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
-
Chad Trabant
2015-04-24 20:32:44
Dear E. Tsakiroudi,
First, let me clarify/correct something I wrote in the previous message. The version of evalresp embedded in sac is configured to always return displacement, converting from velocity or acceleration as needed. Furthermore it assumes that length units are meters and converts them to nanometers to conform to the SAC convention. Again, since SEED strongly recommends SI units and most SEED metadata describes a response in length units of meters it's a relatively safe assumption.
Using the transfer-polezero functionality with the given PZ file will result in displacement in METERS.
Using the evalresp functionality built into sac with the RESP file will result in displacement in NANOMETERS.
Also, I have noticed that the 'RESP' file shows the velocity response and the 'PZfile' shows the displacement response.
Both the SAC PZ file and the RESP file describe a conversion from Earth units to digital counts. The process of restitution (e.g. deconvolution) reverses this conversion, usually within a confined frequency band (or it goes bad quickly). This requires that you start with raw seismograms in units of digital counts. The raw data may be proportional to displacement, velocity or acceleration but you do not really care as long as it is the raw data described by the response.
Does this mean that I have to use only velocity input or only displacement input waveforms, respectively, in each way?
Could I use a displacement input, and remove the instrument with a RESPfile(velocity response)?
regards,
Chad
On Apr 24, 2015, at 5:27 AM, Eva Tsakiroudi <evatsakir<at>yahoo.com> wrote:
Dear Mr. Trabant and Mr. Plasencia,
Thank you so much for your replies!
But, in order to make a final conclusion, so that everyone could understand it, I would be greatful if, someone of you, could confirm the following:
When we remove the instrument from a raw waveform, with the 'tranfer-polezero' way or the 'evalresp' way in SAC, the output units are the ones displayed in the PZfile or the RESPfile, respectively, as follows:
PZ_FILE EXAMPLE:
* Input Units : METERS
* Output Units : COUNTS
RESP_FILE EXAMPLE:
B053F05 Response in units lookup: M/S - Velocity in Meters Per Second
B053F06 Response out units lookup: V - Volts
In this example, the OUTPUT units are in METERS/SEC, disregarding the sac header 'IDEP' which might turn into 'NM/SEC', due to SAC conventions.
Is that correct?
Also, I have noticed that the 'RESP' file shows the velocity response and the 'PZfile' shows the displacement response.
Does this mean that I have to use only velocity input or only displacement input waveforms, respectively, in each way?
Could I use a displacement input, and remove the instrument with a RESPfile(velocity response)?
All these subjects remain unclear for all the new researchers, so we truly appreciate your replies!
Have a nice day!
E. Tsakiroudi
Στις 9:13 μ.μ. Πέμπτη, 23 Απριλίου 2015, ο/η Chad Trabant <chad<at>iris.washington.edu> έγραψε:
Hi Eva,
A point of clarity: I think when using the evalresp option, the units of length (meters, centimeters, nanometers, ...) are whatever is in the RESP file. For the majority of broadband seismic metadata in SEED the length unit is meters, so the assumption is usually good but keep that in mind.
Regarding the setting of IDEP on data you receive from IRIS: most raw seismic data is recorded and archived in units of digital counts, there is no IDEP setting for this. Converting these raw digital counts to Earth units in the general case is non trivial and the method chosen might depend on the study being conducted. We do have a web service at the DMC that performs two different kinds of restitution (deconvolution and scaling): http://service.iris.edu/irisws/timeseries/1/. This service returns a single seismogram and the processing is done on the fly. But even then the IDEP is not set as the length units are again whatever is documented in the RESP and there is not a general enough way to express that variation in IDEP allowed values.
regards,
Chad
On Apr 23, 2015, at 7:01 AM, Milton Plasencia <mplasencia<at>inogs.it <mplasencia<at>inogs.it>> wrote:
Hi,
On Apr 23, 2015, at 15:57, Eva Tsakiroudi <evatsakir<at>yahoo.com <evatsakir<at>yahoo.com>> wrote:
Yes
Dear Mr. Plasencia,
Thank you so much for your reply!
So, you're saying that if I do this procedure on GDSN BB data, the output is VELOCITY in M/SEC. And that if I used the 'evalresp' option, the output would be VELOCITY in NM/SEC ('sac convention'). Is that right?
Also, is there a way for the IDEP of the (downloaded by IRIS and converted to .SAC) data, not to be UNKNOWN?
I think yes, but no depend of me...
E. Tsakiroudi
M.
Cheers,
Στις 4:35 μ.μ. Πέμπτη, 23 Απριλίου 2015, ο/η Milton Plasencia <mplasencia<at>inogs.it <mplasencia<at>inogs.it>> έγραψε:
_______________________________________________
Hi Eva,
The transfer manual say:
For displacements, the SAC convention is nm, while RDSEED RESP files use meters. The EVALRESP option in TRANSFER corrects the output to the SAC convention. For other options (FAP, PZ) it may be ncessary to change the units.
See below
On Apr 23, 2015, at 14:43, Eva Tsakiroudi <evatsakir<at>yahoo.com <evatsakir<at>yahoo.com>> wrote:
OK
Dear Mr. or Mrs.,
I am concerned about the reliability of units before and after the instrument correction.
I followed this exact procedure:
1)downloaded GDSN BB teleseismic waveforms of a 6.9 earthquake from Wilber3(IRIS) in a SEED file
2)converted to SAC files with rdseed program and read them on SAC
OK
3)checked the header : IDEP=UNKNOWN
?? i do not know the reason.
4)used the sac command 'transfer' to remove the instrument using the extracted(from rdseed) PZfiles:
OK, but only for curiosity, the low pass filter (fc 50 60), have you signals sampled at least at 120 Hz or greater?
transfer from polezero subtype %PZfile to vel freq 0.01 0.02 50 60
5)checked again the header : IDEP= VELOCITY (NM/SEC).
OK, in your transfer command you pass to velocity.
The shape of the waveform didn't change at all, so the 'VELOCITY' part of the header is correct.
Here, you must to multiply for 10^9 to obtain nm, in your case velocity (nm/s).
The teleseismic amplitudes changed from *10^5 to *10^(-5) and the earthquake is of Mw=6.9.
Are the NM/SEC units the correct ones?
Use the evalresp option in transfer to correct the units.
Is there a chance that the units are M/SEC?
Which is the safest way to remove the instrument?
The subject of 'reliability of UNITS in SAC headers' is of major significance, especially to new researchers, since various mistakes can easily be done. Any useful reply or advice is greatly appreciated.
I agree.
Thank you in advance!
HOPE TO HELP,
E. Tsakiroudi
Milton
_______________________________________________
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
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
-
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-
-
-
