[CIG-SEISMO] single force solution

[Dimitri Komatitsch]

Hi Hom Nath,

Perfect, thanks!
Then please remember to commit it to GitHub.

Best regards,
Dimitri.

On 04/12/2017 01:06 PM, Hom Nath Gharti wrote:
> Hi Sévan,
>
> I am about to finish new point force implementation. I will let you know
> once it is ready for testing.
>
> Best,
> Hom Nath
>
> On Wed, Apr 12, 2017 at 6:36 AM, Dimitri Komatitsch
> <komatitsch at lma.cnrs-mrs.fr <mailto:komatitsch at lma.cnrs-mrs.fr>> wrote:
>
>
>     Hi Sevan,
>
>     I guess you can keep cc'ing the list because it is an issue Clément,
>     Vadim, Paul, Sébastien and I have been facing as well in our coupling
>     with external codes, thus we are interested in knowing more about the
>     potential problem.
>
>     Thanks,
>     Best wishes,
>     Dimitri.
>
>     On 04/12/2017 11:24 AM, Sevan Adourian wrote:
>     > Hi Hom Nath,
>     >
>     > Thanks for your answer and concern. Since you suggest something that is
>     > not directly "specfem related", can I send you directly an email so that
>     > we can discuss it? And then I can post the solution once we'll find it,
>     > in order to close the topic!
>     >
>     > Thanks again,
>     > Sévan
>     >
>     > On Tue, Apr 11, 2017 at 8:46 PM, Hom Nath Gharti <hgharti at princeton.edu <mailto:hgharti at princeton.edu>
>     > <mailto:hgharti at princeton.edu <mailto:hgharti at princeton.edu>>> wrote:
>     >
>     >     Hi Sévan,
>     >
>     >     Do you also switch the orientations of source and receiver?
>     >
>     >     Thanks,
>     >     Hom Nath
>     >
>     >     On Tue, Apr 11, 2017 at 1:39 PM, Sevan Adourian
>     >     <sevan.adourian at berkeley.edu
>     <mailto:sevan.adourian at berkeley.edu>
>     <mailto:sevan.adourian at berkeley.edu
>     <mailto:sevan.adourian at berkeley.edu>>>
>     >     wrote:
>     >
>     >         Hi cig-seismo community,
>     >
>     >         I'm trying to compute Green's functions using Specfem3D-Globe,
>     >         using a single force point source solution coupled with a
>     source
>     >         time function that basically represents a filtered Dirac
>     delta.
>     >         In order to test my implementation, I imposed a source at a
>     >         point A and looked at the obtained Green's function at a
>     >         receiver B. Then, I switched the position of the source
>     and the
>     >         receiver and compared the 2 in order to check the
>     reciprocity of
>     >         those Green's functions.
>     >
>     >         It turned out that I have a perfect reciprocity (in the
>     >         frequency band that correspond to my filtered Dirac delta)
>     only
>     >         on the component in which I input the force, while the other
>     >         components don't quite match.
>     >
>     >         I strongly suspected a reference frame rotation issue, so I
>     >         tried to input the force in the global xyz coordinate system
>     >         (i.e. adding the force directly in the accel_crust_mantle
>     array
>     >         in the comp_add_sources subroutine, without multiplying
>     with the
>     >         nu_source matrix) and looked at the Green's functions in this
>     >         xyz coordinates system (ie, directly writing in the
>     seismograms
>     >         structure the values of ux, uy and uz computed in the
>     >         compute_seismogram subroutine), but I still have this issue.
>     >         Would anyone have an idea of where this probable rotation
>     issue
>     >         could come from?
>     >
>     >         I'm working on specfem3D-Globe v6.0.0.
>     >
>     >         Thanks in advance for your help!
>     >         Sévan
>     >
>     >         --
>     >         Sevan Adourian
>     >         Masters Student at Ecole Normale Superieure de Paris
>     >         sevan.adourian at ens.fr <mailto:sevan.adourian at ens.fr>
>     <mailto:sevan.adourian at ens.fr <mailto:sevan.adourian at ens.fr>>
>     >
>     >
>     >
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>     >
>     >
>     >
>     >
>     > --
>     > Sevan Adourian
>     > Masters Student at Ecole Normale Superieure de Paris
>     > sevan.adourian at ens.fr <mailto:sevan.adourian at ens.fr>
>     <mailto:sevan.adourian at ens.fr <mailto:sevan.adourian at ens.fr>>
>     >
>     >
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>     >
>
>     --
>     Dimitri Komatitsch, CNRS Research Director (DR CNRS)
>     Laboratory of Mechanics and Acoustics, Marseille, France
>     http://komatitsch.free.fr
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-- 
Dimitri Komatitsch, CNRS Research Director (DR CNRS)
Laboratory of Mechanics and Acoustics, Marseille, France
http://komatitsch.free.fr