Thread: question about rdseed and transfer command.

Started: 2011-11-21 23:52:39
Last activity: 2011-11-21 23:52:39
Topics: SAC Help
yueling
2011-11-21 23:52:39
Hi,


Recently, I transferred velociy record SEED file to SAC file by rdseed,

First, I use the command:

"rdseed -f 200805120628045.SC.SEED -R -d -o -p 1"
so the Poles and Zeros file are outputed,

such as:
SAC_PZs_SC_ZJG_BHZ_00_2007.182.00.00.00.0000_2009.182.24.60.60.99999
*Can I specify the file name without the last part of number?* such as
“SAC_PZs_SC_ZJG_BHZ_”
.

Second, I need to remove the instrument response of the data.
*Can I use the transfer command as:*
"r 2008*ZJG*BHZ*SAC"

"Transfer from polezero subtype
SAC_PZs_SC_ZJG_BHZ_00_2007.182.00.00.00.0000_2009.182.24.60.60.99999
to VEL"
As a result, the output on the terminal is :
**********************************

Extracting polezero response for ZJG , BHZ ...



Station (ZJG ), Channel (BHZ )

Calper is not available. Cannot tell if response is normalized, so
transfer function will be used without scaling.

Calib is not available. Cannot tell if scale factor has been applied
on input, so transfer function will be used without scaling.

Waveform multiplied by 1.000000 after deconvolution.
**********************************


The details of
SAC_PZs_SC_ZJG_BHZ_00_2007.182.00.00.00.0000_2009.182.24.60.60.99999 is as
follow:

* **********************************

* NETWORK (KNETWK): SC

* STATION (KSTNM): ZJG

* LOCATION (KHOLE): 00

* CHANNEL (KCMPNM): BHZ

* CREATED : 2011-11-21T06:54:02

* START : 2007-07-01T00:00:00

* END : 2009-07-02T01:01:00

* DESCRIPTION : Jiangyouzhongjiagou,Sichuan Province

* LATITUDE : 31.792500

* LONGITUDE : 104.672900

* ELEVATION : 612.0

* DEPTH : 0.0

* DIP : 0.0

* AZIMUTH : 0.0

* SAMPLE RATE : 100.0

* INPUT UNIT : M

* OUTPUT UNIT : COUNTS

* INSTTYPE : Guralp CMG-3ESPC Seismometer

* INSTGAIN : 1.929980e+03 (M/S)

* COMMENT : N/A

* SENSITIVITY : 1.214590e+09 (M/S)

* A0 : 5.715080e+08

* **********************************

ZEROS 3

+0.000000e+00 +0.000000e+00

+0.000000e+00 +0.000000e+00

+0.000000e+00 +0.000000e+00

POLES 5

-7.397840e-02 +7.397840e-02

-7.397840e-02 -7.397840e-02

-1.004800e+03 +0.000000e+00

-5.024000e+02 +0.000000e+00

-1.130400e+03 +0.000000e+00
CONSTANT +6.941478e+17

Thanks.

Yueling

  • Sheila Peacock
    2011-11-21 16:40:54
    Dear Yueling Jing,

    You do not need to worry about the messages from SAC, I think.
    RDSEED has scaled the "constant" of your poles-and-zeros to
    incorporate the "sensitivity" into it, so you do not need
    a separate calibration factor ("calib"), i.e.

    constant, 6.941478e17 is equal to

    A0 normalisation factor 5.71508e8 x sensitivity 1.21459e9 m/s/digital count

    and the A0 normalisation factor was calculated on the
    assumption that the calibration period (calper) was one second
    (I have checked this with my program that finds the ratio of the
    polynomials).

    You can check that the calibration period really is one second
    by sending for the data sheet for the seismometer from Guralp.
    Send an email to caldoc<at>guralp.com with the serial number
    of the seismometer in the header. You should receive the data
    sheet as a Microsoft Word document automatically.

    The calibration factor "calib", in case you need it for other
    purposes, is given by 1/(sensitivity in m/s * 2pi), but in
    metres/count (so multiply by 10^9 if you need it in nanometres/count).
    I make yours 1.310359e-10 metres/count. If you want to check
    that the value is correct, you need to get the digitiser data
    sheet as well as the seismometer data sheet. If it is a Guralp
    digitiser then you can obtain this from caldoc<at>guralp.com
    by putting the serial number of the digitiser on to the subject
    line of the email (but beware that the resulting Microsoft Word
    file will not display the values properly in OpenOffice, only in
    genuine Microsoft Word).

    Guralp seismometer data sheets give poles and zeros in terms of
    hertz not radians, and in terms of velocity not displacement,
    so you will find that there are only two zeros, not three, in
    the data sheet for the seismometer, and
    the poles need to be multiplied by 2pi/calper to match the
    ones reported by rdseed.

    Regards,
    Sheila Peacock.

    On 11/21/2011 07:52 AM, Yueling Jing wrote:

    Hi,

    Recently, I transferred velociy record SEED file to SAC file by rdseed,

    First, I use the command:

    "rdseed -f 200805120628045.SC.SEED -R -d -o -p 1"

    so the Poles and Zeros file are outputed,

    such as: SAC_PZs_SC_ZJG_BHZ_00_2007.182.00.00.00.0000_2009.182.24.60.60.99999

    *Can I specify the file name without the last part of number?* such as “SAC_PZs_SC_ZJG_BHZ_” .
    Second, I need to remove the instrument response of the data.
    *Can I use the transfer command as:*
    "r 2008*ZJG*BHZ*SAC"

    "Transfer from polezero subtype SAC_PZs_SC_ZJG_BHZ_00_2007.182.00.00.00.0000_2009.182.24.60.60.99999 to VEL"

    As a result, the output on the terminal is :
    **********************************

    Extracting polezero response for ZJG, BHZ...

    Station (ZJG), Channel (BHZ)

    Calper is not available. Cannot tell if response is normalized, so transfer function will be used without scaling.

    Calib is not available. Cannot tell if scale factor has been applied on input, so transfer function will be used without scaling.

    Waveform multiplied by 1.000000 after deconvolution.

    **********************************

    The details of SAC_PZs_SC_ZJG_BHZ_00_2007.182.00.00.00.0000_2009.182.24.60.60.99999 is as follow:

    * **********************************

    * NETWORK(KNETWK): SC

    * STATION(KSTNM): ZJG

    * LOCATION(KHOLE): 00

    * CHANNEL(KCMPNM): BHZ

    * CREATED: 2011-11-21T06:54:02

    * START: 2007-07-01T00:00:00

    * END: 2009-07-02T01:01:00

    * DESCRIPTION: Jiangyouzhongjiagou,Sichuan Province

    * LATITUDE: 31.792500

    * LONGITUDE: 104.672900

    * ELEVATION: 612.0

    * DEPTH: 0.0

    * DIP: 0.0

    * AZIMUTH: 0.0

    * SAMPLE RATE: 100.0

    * INPUT UNIT: M

    * OUTPUT UNIT: COUNTS

    * INSTTYPE: Guralp CMG-3ESPC Seismometer

    * INSTGAIN: 1.929980e+03 (M/S)

    * COMMENT: N/A

    * SENSITIVITY: 1.214590e+09 (M/S)

    * A0: 5.715080e+08

    * **********************************

    ZEROS3

    +0.000000e+00+0.000000e+00

    +0.000000e+00+0.000000e+00

    +0.000000e+00+0.000000e+00

    POLES5

    -7.397840e-02+7.397840e-02

    -7.397840e-02-7.397840e-02

    -1.004800e+03+0.000000e+00

    -5.024000e+02+0.000000e+00

    -1.130400e+03+0.000000e+00

    CONSTANT+6.941478e+17
    Thanks.
    Yueling



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