International Federation of Digital Seismograph Networks

Thread: guidelines for band code assignment

None
Started: June 21, 2011, 3:05 p.m.
Last activity: June 23, 2011, 3:55 p.m.
Sleeman, Reinoud (KNMI)
June 21, 2011, 3:05 p.m.
Dear WG II members,

During the preparation for the next WG II meeting in Melbourne I noticed
the following request made by Doug Neuhauser, upon which our WG never
took
further action (?).

A pragmatic solution would be to keep the current band code in place for
the
seismometers and define new ones for accelerometers and other
geophysical instruments
based on the sample rate only, for example:

I sr >= 1000 Hz
J sr: 250 Hz - 1000 Hz
K sr: 100 Hz - 250 Hz
N sr: 1 Hz - 10 Hz
P sr: ~ 1 Hz
W sr: ~ 0.1 Hz
X sr: ~ 0.01 Hz
Y sr < 0.01 Hz

Please let me know your thoughts.

I will send you a draft agenda for the WG II meeting today or tomorrow.

Cheers,
Reinoud




From: Doug Neuhauser <doug at seismo.berkeley.edu>
Date: December 24, 2008 12:36:07 PM PST
Subject: SEED band code clarification requested

The SEED manual (Appendix A) provides some guidelines for band code
assignment based on sample rate, and for higher sampling rate, based
on corner frequency. These have recently been extended to define
band codes for higher sample rates based on the same corner frequency
guidelines.

Band Band type Sample rate Corner period
code (sec)
---------------------------------------------------------------------
B Broad band >= 10 to < 80 >= 10 sec
H High Broad Band >= 80 to < 250 >= 10 sec
C ... >= 250 to < 1000 >= 10 sec
F ... >= 1000 to < 5000 >= 10 sec

S Short Period >= 10 to < 80 < 10 sec
E Extreme Short Period >= 80 to < 250 < 10 sec
D ... >= 250 to < 1000 < 10 sec
G ... >= 1000 to < 5000 < 10 sec

I and others in the SEED community would like some clarification and
guidance
on what the term "Corner period (sec)" refers to. Specifically, it is
not
clear into which of the above "corner period" categories data from
accelerometers and other geophysical instruments such as electric and
magnetic
field sensors should be classified.

For traditional accelerometers:
If the "corner period in seconds" refers to the lower corner of the
flat
passband of the measured observation (eg acceleration for an
accelerometer),
then I would infer that accelerometers should be classified along with
"broadband" sensors in the first group of band codes where the corner
period
of >= 10 seconds, since the response of acceleromters is flat to ~DC
(0 Hz ~=
infinity seconds). However, if the corner period in seconds refers to
the
natural period of the actual sensor, most accelerometers have a
natural period
of several Hz (< 1 second), from which I would infer that they should
be
classified with "short period" on the second group of band codes with
a corner
period of < 10 seconds. If the corner period is based on the
characteristics
of the physical sensor, and not of the property of the data produced
by the
sensor, it is unclear how this may change for non-traditional sensors
such as
silicon-based or fluid sensors.

It sould be extremely helpful to have additional guidelines to help
the SEED community standardize on channel names. Currently, I have
seen both E and H bandcodes uses for 100 Hz accelerometer data,
and the same confusion exists for higher sample rates.

For other geophysical data channels such as electric and magentic
field
sensors, the same question arises. For both electric and magnetic
field data
channels, the response of data channels are often flat to close to DC,
so I
would infer that they should be classified along with the broad band
sensors.
However, if the classification is based on the senor characteristics,
it is is
not clear what characteristics of the actual sensor you would use for
classification.






  • Winfried Hanka
    June 23, 2011, 3:55 p.m.
    Dear all,

    according to the SEED manual it looks like band code P is already taken for

    sr :"on the order of 0.1 to 1 day* ≥ 0.00001 to < 0.0001"

    I am not sure if anybody is using it though. Otherwise I have no objections.

    Regards,

    Winfried


    On 06/21/11 15:05, Sleeman, Reinoud (KNMI) wrote:
    Dear WG II members,



    During the preparation for the next WG II meeting inMelbourne I noticed

    the following request made by Doug Neuhauser, upon which our WG never took

    further action (?).



    A pragmatic solution would be to keep the current band code in place for the

    seismometers and define new ones for accelerometers and other geophysical instruments

    based on the sample rate only, for example:



    I sr>= 1000 Hz

    J sr: 250 Hz– 1000 Hz

    K sr: 100 Hz– 250 Hz

    N sr: 1 Hz– 10 Hz

    P sr: ~ 1 Hz

    W sr: ~ 0.1 Hz

    X sr: ~ 0.01 Hz

    Y sr< 0.01 Hz



    Please let me know your thoughts.



    I will send you a draft agenda for the WG II meeting today or tomorrow.



    Cheers,

    Reinoud









    From: Doug Neuhauser<doug at seismo.berkeley.edu>

    Date: December 24, 2008 12:36:07 PM PST

    Subject: SEED band code clarification requested



    The SEED manual (Appendix A) provides some guidelines for band code

    assignment based on sample rate, and for higher sampling rate, based

    on corner frequency. These have recently been extended to define

    band codes for higher sample rates based on the same corner frequency

    guidelines.



    Band Band type Sample rate Corner period

    code (sec)

    ---------------------------------------------------------------------

    B Broad band >= 10 to< 80 >= 10 sec

    H High Broad Band >= 80 to< 250 >= 10 sec

    C ... >= 250 to< 1000 >= 10 sec

    F ... >= 1000 to< 5000 >= 10 sec



    S Short Period >= 10 to< 80 < 10 sec

    E Extreme Short Period >= 80 to< 250 < 10 sec

    D ... >= 250 to< 1000 < 10 sec

    G ... >= 1000 to< 5000 < 10 sec



    I and others in the SEED community would like some clarification and guidance

    on what the term"Corner period (sec)" refers to. Specifically, it is not

    clear into which of the above"corner period" categories data from

    accelerometers and other geophysical instruments such as electric and magnetic

    field sensors should be classified.



    For traditional accelerometers:

    If the"corner period in seconds" refers to the lower corner of the flat

    passband of the measured observation (eg acceleration for an accelerometer),

    then I would infer that accelerometers should be classified along with

    "broadband" sensors in the first group of band codes where the corner period

    of>= 10 seconds, since the response of acceleromters is flat to ~DC (0 Hz ~=

    infinity seconds). However, if the corner period in seconds refers to the

    natural period of the actual sensor, most accelerometers have a natural period

    of several Hz (< 1 second), from which I would infer that they should be

    classified with"short period" on the second group of band codes with a corner

    period of< 10 seconds. If the corner period is based on the characteristics

    of the physical sensor, and not of the property of the data produced by the

    sensor, it is unclear how this may change for non-traditional sensors such as

    silicon-based or fluid sensors.



    It sould be extremely helpful to have additional guidelines to help

    the SEED community standardize on channel names. Currently, I have

    seen both E and H bandcodes uses for 100 Hz accelerometer data,

    and the same confusion exists for higher sample rates.



    For other geophysical data channels such as electric and magentic field

    sensors, the same question arises. For both electric and magnetic field data

    channels, the response of data channels are often flat to close to DC, so I

    would infer that they should be classified along with the broad band sensors.

    However, if the classification is based on the senor characteristics, it is is

    not clear what characteristics of the actual sensor you would use for classification.







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