[CIG-SEISMO] specfem2d receivers on surface with an external mesh / PS

[Giuseppe Di Giulio]

Hi Dimitri

I am using the release 7.0.

I will try with the most recent one.

Thanks
Giuseppe


2017-11-07 16:33 GMT+01:00 Dimitri Komatitsch <komatitsch at lma.cnrs-mrs.fr>:

>
> Dear Giuseppe,
>
> Using a single receiver per set, as in your:
>
> # first receiver line
> nrec                            = 1             # number of receivers
> xdeb                            = 10.           # first receiver x in
> meters
> zdeb                            = 880.          # first receiver z in
> meters
> xfin                            = 2500.          # last receiver x in
> meters (ignored if onlyone receiver)
> zfin                            = 870.000427          # last receiver z in
> meters (ignored if onlyone receiver)
> enreg_surf_same_vertical        = .false.         # receivers inside the
> medium or at the surface
>
> # second receiver line
> nrec                            = 1             # number of receivers
> xdeb                            = 1000.           # first receiver x in
> meters
> zdeb                            = 1000.          # first receiver z in
> meters
> xfin                            = 2500.          # last receiver x in
> meters (ignored if onlyone receiver)
> zfin                            = 870.000427          # last receiver z in
> meters (ignored if onlyone receiver)
> enreg_surf_same_vertical        = .false.         # receivers inside the
> medium or at the surface
>
> works fine here though. Are you using a recent version of the code?
>
> Cheers,
> Dimitri.
>
> On 11/07/2017 03:59 PM, Dimitri Komatitsch wrote:
>
>>
>> Dear Giuseppe, dear all,
>>
>> You are right, option "enreg_surf_same_vertical" in the Par_file
>> currently does not work for external meshes because we have no easy way of
>> knowing where the topography is in an external mesh (we would need to have
>> a list of all element edges that are along the upper surface; could be
>> done, but not done yet; not too difficult).
>>
>> In the meantime the easiest thing to do is probably to zoom on your
>> topography in Gmesh (zooming a lot) and then click on the point where you
>> want your receiver to be located, and write down the coordinates of that
>> point (and then enter that manually in the Par_file).
>>
>> Best regards,
>> Dimitri.
>>
>> On 11/06/2017 01:26 PM, Giuseppe Di Giulio wrote:
>>
>>> ​​​​​
>>> profilo_geo.msh.gz <https://drive.google.com/a/in
>>> gv.it/file/d/19zHUn9T6deq0q1KeVzeJs0jqAw3uFkaR/view?usp=drive_web>
>>> ​​​Dear SpecFem developers
>>>
>>> I am using Specfem2D 7.0 with an external mesh (built by gmsh) aimed at
>>> investigating the topographic effect.
>>>
>>> My will is to fix the position of the receivers on the topographyc
>>> surface.
>>>
>>> My understanding is that the parameter "enreg_surf_same_vertical" in the
>>> Par_file cannot be "true" with an external mesh.
>>>
>>> I try to set multiple receiver lines in the Par file where (xdeb,zdeb)
>>> are the coordinates of my receivers. The receiver lines (nreceiversets
>>> parameter) are fixed to the same number of receivers, and  nrec is equal to
>>> 1 for each receiver line (and for this I do not care of xfin and zfin; see
>>> the end of message).
>>>
>>> Unfortunately it does not work, the error message after the run of
>>> xmeshfem2D is
>>>
>>> "At line 326 of file ../shared/read_value_parameters.f90
>>> Fortran runtime error: Bad real number in item 1 of list input"
>>>
>>> Any suggestion to place receivers on topographic surface with an
>>> external  2D mesh is welcome.
>>>
>>> The Par_file and my mesh are available as attach
>>>
>>> Thanks
>>>
>>> Giuseppe
>>>
>>>
>>> # first receiver line
>>> nrec                            = 1             # number of receivers
>>> xdeb                            = 10.           # first receiver x in
>>> meters
>>> zdeb                            = 880.          # first receiver z in
>>> meters
>>> xfin                            = 2500.          # last receiver x in
>>> meters (ignored if onlyone receiver)
>>> zfin                            = 870.000427          # last receiver z
>>> in meters (ignored if onlyone receiver)
>>> enreg_surf_same_vertical        = .false.         # receivers inside
>>> the medium or at the surface
>>>
>>> # second receiver line
>>> nrec                            = 1             # number of receivers
>>> xdeb                            = 1000.           # first receiver x in
>>> meters
>>> zdeb                            = 1000.          # first receiver z in
>>> meters
>>> xfin                            = 2500.          # last receiver x in
>>> meters (ignored if onlyone receiver)
>>> zfin                            = 870.000427          # last receiver z
>>> in meters (ignored if onlyone receiver)
>>> enreg_surf_same_vertical        = .false.         # receivers inside
>>> the medium or at the surface
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> CIG-SEISMO mailing list
>>> CIG-SEISMO at geodynamics.org
>>> http://lists.geodynamics.org/cgi-bin/mailman/listinfo/cig-seismo
>>>
>>>
>>
> --
> Dimitri Komatitsch, CNRS Research Director (DR CNRS)
> Laboratory of Mechanics and Acoustics, Marseille, France
> http://komatitsch.free.fr
>
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