sanjay Singh Negi
Hi,
What algorithm is followed when we use sac rotate, reverse or normal
For e.g., in sac the difference between
rotate to gcp normal
and
rotate to gcp reverse
Thank you
Regards
Sanjay
What algorithm is followed when we use sac rotate, reverse or normal
For e.g., in sac the difference between
rotate to gcp normal
and
rotate to gcp reverse
Thank you
Regards
Sanjay
-
Hi,
I invite you to see the information on sac help,
sac> help rotate
INPUT
-----
:TO GCP: Rotate to the "great circle path". Both components must be
horizontals. The station and event coordinates header fields must
be defined.
:TO v: Rotate to the angle v (degrees). Both components must be
horizontals.
:THROUGH v: Rotate through the angle v in degrees. One component may
be vertical.
:NORMAL: Output (horizontal) components with the second leading the
first by 90 degrees
:REVERSED: Output (horizontal) components with the second lagging the
first by 90 degrees.
DEFAULT VALUES
--------------
::
ROTATE TO GCP NORMAL
HTH,
Milton
----------------------------
Milton P. Plasencia Linares
mpplasencia@ <mplasencia<at>inogs.it>gmail.com
On Fri, May 8, 2020 at 12:53 AM sanjay Singh Negi (via IRIS) <
sac-help<at>lists.ds.iris.edu> wrote:
Hi,
What algorithm is followed when we use sac rotate, reverse or normal
For e.g., in sac the difference between
rotate to gcp normal
and
rotate to gcp reverse
Thank you
Regards
Sanjay
----------------------
SAC Help
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-
If North is zero degrees, East is 90 degrees, so East leads North by 90 degrees.
There is some confusion with the conventions because SAC defines
upward-vertical as positive, while others (e.g., Kennett) define
downward-vertical as positive. So for the SAC convention, Vertical, North, and
East is a left-handed coordinate system.
On 5/7/20 7:34 PM, Milton Plasencia (via IRIS) wrote:
Hi,
I invite you to see the information on sac help,
sac> help rotate
INPUT
-----
:TO GCP: Rotate to the "great circle path". Both components must be
horizontals. The station and event coordinates header fields must
be defined.
:TO v: Rotate to the angle v (degrees). Both components must be
horizontals.
:THROUGH v: Rotate through the angle v in degrees. One component may
be vertical.
:NORMAL: Output (horizontal) components with the second leading the first by
90 degrees
:REVERSED: Output (horizontal) components with the second lagging the first
by 90 degrees.
DEFAULT VALUES
--------------
::
ROTATE TO GCP NORMAL
HTH,
Milton
----------------------------
Milton P. Plasencia Linares
mpplasencia@ <mplasencia<at>inogs.it>gmail.com http://gmail.com
On Fri, May 8, 2020 at 12:53 AM sanjay Singh Negi (via IRIS)
<sac-help<at>lists.ds.iris.edu <sac-help<at>lists.ds.iris.edu>> wrote:
Hi,
What algorithm is followed when we use sac rotate, reverse or normal
For e.g., in sac the difference between
rotate to gcp normal
and
rotate to gcp reverse
Thank you
Regards
Sanjay
----------------------
SAC Help
Topic home: http://ds.iris.edu/message-center/topic/sac-help/ |
Unsubscribe: sac-help-unsubscribe<at>lists.ds.iris.edu
<sac-help-unsubscribe<at>lists.ds.iris.edu>
Sent from the IRIS Message Center (http://ds.iris.edu/message-center/)
Update subscription preferences at http://ds.iris.edu/account/profile/
----------------------
SAC Help
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-
You are absolutely correct. However, we know that for the right-handed
system,
where east component lags behind the north component by 90 deg, we use
reverse option.
Actually, after reading the rotate help section, I was able to clear that
the for reverse case, changes are applied in the output directions.
Earlier, I was confused that whether the coordinate system is changed while
rotation or not?
It was really very helpful.
Thank you,
Regards
Sanjay
On Fri, May 8, 2020 at 8:51 AM Arthur Snoke (via IRIS) <
sac-help<at>lists.ds.iris.edu> wrote:
If North is zero degrees, East is 90 degrees, so East leads North by 90
--
degrees.
There is some confusion with the conventions because SAC defines
upward-vertical as positive, while others (e.g., Kennett) define
downward-vertical as positive. So for the SAC convention, Vertical,
North, and
East is a left-handed coordinate system.
On 5/7/20 7:34 PM, Milton Plasencia (via IRIS) wrote:
Hi,
first by
I invite you to see the information on sac help,
sac> help rotate
INPUT
-----
:TO GCP: Rotate to the "great circle path". Both components must be
horizontals. The station and event coordinates header fields must
be defined.
:TO v: Rotate to the angle v (degrees). Both components must be
horizontals.
:THROUGH v: Rotate through the angle v in degrees. One component may
be vertical.
:NORMAL: Output (horizontal) components with the second leading the
90 degrees
first
:REVERSED: Output (horizontal) components with the second lagging the
by 90 degrees.
http://ds.iris.edu/message-center/)
DEFAULT VALUES
--------------
::
ROTATE TO GCP NORMAL
HTH,
Milton
----------------------------
Milton P. Plasencia Linares
mpplasencia@ <mplasencia<at>inogs.it>gmail.com http://gmail.com
On Fri, May 8, 2020 at 12:53 AM sanjay Singh Negi (via IRIS)
<sac-help<at>lists.ds.iris.edu <sac-help<at>lists.ds.iris.edu>> wrote:
Hi,
What algorithm is followed when we use sac rotate, reverse or normal
For e.g., in sac the difference between
rotate to gcp normal
and
rotate to gcp reverse
Thank you
Regards
Sanjay
----------------------
SAC Help
Topic home: http://ds.iris.edu/message-center/topic/sac-help/ |
Unsubscribe: sac-help-unsubscribe<at>lists.ds.iris.edu
<sac-help-unsubscribe<at>lists.ds.iris.edu>
Sent from the IRIS Message Center (
Update subscription preferences at
http://ds.iris.edu/account/profile/
----------------------
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SAC Help
Topic home: http://ds.iris.edu/message-center/topic/sac-help/ |
Sent from the IRIS Message Center (http://ds.iris.edu/message-center/)
----------------------
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SAC Help
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Sanjay Singh Negi
Alternate Email: sasnegi85<at>gmail.com
Contact No.- +91-9536145596
-
-
Thanks for the information. As I have already gone through the information,
but I need an understanding as to what is going behind the command.
Regars
On Fri, May 8, 2020, 05:08 Milton Plasencia (via IRIS) <
sac-help<at>lists.ds.iris.edu> wrote:
Hi,
I invite you to see the information on sac help,
sac> help rotate
INPUT
-----
:TO GCP: Rotate to the "great circle path". Both components must be
horizontals. The station and event coordinates header fields must
be defined.
:TO v: Rotate to the angle v (degrees). Both components must be
horizontals.
:THROUGH v: Rotate through the angle v in degrees. One component may
be vertical.
:NORMAL: Output (horizontal) components with the second leading the
first by 90 degrees
:REVERSED: Output (horizontal) components with the second lagging the
first by 90 degrees.
DEFAULT VALUES
--------------
::
ROTATE TO GCP NORMAL
HTH,
Milton
----------------------------
Milton P. Plasencia Linares
mpplasencia@ <mplasencia<at>inogs.it>gmail.com
On Fri, May 8, 2020 at 12:53 AM sanjay Singh Negi (via IRIS) <
sac-help<at>lists.ds.iris.edu> wrote:
Hi,
----------------------
What algorithm is followed when we use sac rotate, reverse or normal
For e.g., in sac the difference between
rotate to gcp normal
and
rotate to gcp reverse
Thank you
Regards
Sanjay
----------------------
SAC Help
Topic home: http://ds.iris.edu/message-center/topic/sac-help/ |
Unsubscribe: sac-help-unsubscribe<at>lists.ds.iris.edu
Sent from the IRIS Message Center (http://ds.iris.edu/message-center/)
Update subscription preferences at http://ds.iris.edu/account/profile/
SAC Help
Topic home: http://ds.iris.edu/message-center/topic/sac-help/ |
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-
Thank you Milton,
I went through the help section.
I now understand that the output directions are changed when we use the
reverse option in rotating the seismogram.
It was really very helpful.
Thank you,
Regards
Sanjay
On Fri, May 8, 2020 at 5:08 AM Milton Plasencia (via IRIS) <
sac-help<at>lists.ds.iris.edu> wrote:
Hi,
--
I invite you to see the information on sac help,
sac> help rotate
INPUT
-----
:TO GCP: Rotate to the "great circle path". Both components must be
horizontals. The station and event coordinates header fields must
be defined.
:TO v: Rotate to the angle v (degrees). Both components must be
horizontals.
:THROUGH v: Rotate through the angle v in degrees. One component may
be vertical.
:NORMAL: Output (horizontal) components with the second leading the
first by 90 degrees
:REVERSED: Output (horizontal) components with the second lagging the
first by 90 degrees.
DEFAULT VALUES
--------------
::
ROTATE TO GCP NORMAL
HTH,
Milton
----------------------------
Milton P. Plasencia Linares
mpplasencia@ <mplasencia<at>inogs.it>gmail.com
On Fri, May 8, 2020 at 12:53 AM sanjay Singh Negi (via IRIS) <
sac-help<at>lists.ds.iris.edu> wrote:
Hi,
----------------------
What algorithm is followed when we use sac rotate, reverse or normal
For e.g., in sac the difference between
rotate to gcp normal
and
rotate to gcp reverse
Thank you
Regards
Sanjay
----------------------
SAC Help
Topic home: http://ds.iris.edu/message-center/topic/sac-help/ |
Unsubscribe: sac-help-unsubscribe<at>lists.ds.iris.edu
Sent from the IRIS Message Center (http://ds.iris.edu/message-center/)
Update subscription preferences at http://ds.iris.edu/account/profile/
SAC Help
Topic home: http://ds.iris.edu/message-center/topic/sac-help/ |
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Sent from the IRIS Message Center (http://ds.iris.edu/message-center/)
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Sanjay Singh Negi
Alternate Email: sasnegi85<at>gmail.com
Contact No.- +91-9536145596
-
Milton Plasencia
Arthur Snoke
