Dear sac-help:
I am wanting to compare synthetic seismograms computed using a
flat-earth model using two different techniques. It seems like it
would be easiest to "turn off" the sphericity/ellipticity of the
Earth, and then input the source and station locations in, say, km.
And then the azimuth and back-azimuth angles would differ by exactly
180 degrees. I do not see a sac header that might do this -- is there
a simple solution? Alternatively, it seems I could set LCALDA = false,
and then manually enter at least some information, but it would be
safer to have sac to the computations based on input source and
station locations.
Thanks,
Carl
---------------------------------------------------------------
Carl Tape
Assistant Professor
Geophysical Institute
University of Alaska Fairbanks
Phone: 907-474-5456
Email: carltape<at>gi.alaska.edu
Web: http://www.giseis.alaska.edu/input/carl/
---------------------------------------------------------------
I am wanting to compare synthetic seismograms computed using a
flat-earth model using two different techniques. It seems like it
would be easiest to "turn off" the sphericity/ellipticity of the
Earth, and then input the source and station locations in, say, km.
And then the azimuth and back-azimuth angles would differ by exactly
180 degrees. I do not see a sac header that might do this -- is there
a simple solution? Alternatively, it seems I could set LCALDA = false,
and then manually enter at least some information, but it would be
safer to have sac to the computations based on input source and
station locations.
Thanks,
Carl
---------------------------------------------------------------
Carl Tape
Assistant Professor
Geophysical Institute
University of Alaska Fairbanks
Phone: 907-474-5456
Email: carltape<at>gi.alaska.edu
Web: http://www.giseis.alaska.edu/input/carl/
---------------------------------------------------------------
-
The easiest way might be to put the station and the event on the
equator, then az and baz are 180 off each other and the ellipticity
doesn't impact the distance.
Philip
On Fri, Jul 8, 2011 at 5:24 PM, Carl Tape <carltape<at>gi.alaska.edu> wrote:
Dear sac-help:
I am wanting to compare synthetic seismograms computed using a
flat-earth model using two different techniques. It seems like it
would be easiest to "turn off" the sphericity/ellipticity of the
Earth, and then input the source and station locations in, say, km.
And then the azimuth and back-azimuth angles would differ by exactly
180 degrees. I do not see a sac header that might do this -- is there
a simple solution? Alternatively, it seems I could set LCALDA = false,
and then manually enter at least some information, but it would be
safer to have sac to the computations based on input source and
station locations.
Thanks,
Carl
---------------------------------------------------------------
Carl Tape
Assistant Professor
Geophysical Institute
University of Alaska Fairbanks
Phone: 907-474-5456
Email: carltape<at>gi.alaska.edu
Web: http://www.giseis.alaska.edu/input/carl/
---------------------------------------------------------------
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sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
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Hi Philip,
Thanks, but that still leads to the issue of having the wrong headers.
I am comparing source radiation at stations with different azimuths,
so the headers need to be correct -- and, ideally, appropriate for a
flat earth.
It doesn't sound like turning of earth sphericity (or ellipticity) is
an option, which is fine. I was just checking.
Thanks,
Carl
On Mon, Jul 11, 2011 at 12:24 PM, Philip Crotwell <crotwell<at>seis.sc.edu> wrote:
The easiest way might be to put the station and the event on the
equator, then az and baz are 180 off each other and the ellipticity
doesn't impact the distance.
Philip
On Fri, Jul 8, 2011 at 5:24 PM, Carl Tape <carltape<at>gi.alaska.edu> wrote:
Dear sac-help:
I am wanting to compare synthetic seismograms computed using a
flat-earth model using two different techniques. It seems like it
would be easiest to "turn off" the sphericity/ellipticity of the
Earth, and then input the source and station locations in, say, km.
And then the azimuth and back-azimuth angles would differ by exactly
180 degrees. I do not see a sac header that might do this -- is there
a simple solution? Alternatively, it seems I could set LCALDA = false,
and then manually enter at least some information, but it would be
safer to have sac to the computations based on input source and
station locations.
Thanks,
Carl
---------------------------------------------------------------
Carl Tape
Assistant Professor
Geophysical Institute
University of Alaska Fairbanks
Phone: 907-474-5456
Email: carltape<at>gi.alaska.edu
Web: http://www.giseis.alaska.edu/input/carl/
---------------------------------------------------------------
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sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help
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