[OpendTect_Users] Convert UTM Zone in segy file

[Arnaud Huck]

Dear Michel, Duncan,

I wish to remind you that all data loaded in OpendTect is referenced 
with respect to the seismic inlines and crosslines, except for the 2D 
seismic lines and well deviation surveys.
The coordinates are always computed using the transformation defined by 
the survey geometry. As a result, one could alter the survey geometry 
coordinates (for instance divide all coordinates by 10 if you forget to 
scale the trace coordinates during import from SEG-Y) without having to 
re-load all data.

Also incoming v4.2 will feature a 2D Geometry manager allowing this kind 
of data manipulation for loaded 2D data (seismic lines, 2D interpretations).

Finally, I would propose the following workflow:
1- Load both surveys using their geometry
2- Use an online utility to convert the corner points of survey #2 to 
the UTM zone of survey #1 (see 
http://www.uwgb.edu/dutchs/usefuldata/ConvertUTMNoOZ.HTM)

Also we are building a seismic survey gridder, that will be released in 
the next development release of OpendTect 4.3, after 4.2. This will add 
step 3 to the workflow (requires both surveys to use the same X-Y reference)
3- Import (grid) the data from survey #2 on the grid of survey #1, in 
survey #1.

Best regards,
Arnaud Huck.

-- Senior Geoscientist
-- dGB Earth Sciences
-- Nijverheidstraat 11-2, 7511 JM Enschede, The Netherlands
-- mailto: arnaud.huck at dgbes.com, http://www.dgbes.com
-- Tel: +31 53 4315155 , Fax: +31 53 4315104


On 04/01/2011 09:28 AM, Duncan Irving wrote:
> Hi,
>
> I've done this with 2D in Seismic Unix so the principle should apply
> although the technicalities will need to be enhanced for trace indexing:
>
> 1/ Dump the trace headers so that you are left with traceids,
> shotpoints, CDPs and (lat,lon). You will need to have a way of indexing
> the traces in the survey for later.
> 2/ Use GMT (gmtproject) to convert the UTM zone. This is fiddly to set
> up but will be a one-liner when you have the parameters correct.
> 3/ Re-write the (lat,lon)s back into the original file. I'm not sure how
> you would do this with a 3D volume - maybe Madagascar? I looped through
> 2D lines trace-by-trace but this may be more challenging with a 3D survey.
>
> I did this a few years ago with bash, Seismic Unix and GMT. You can
> probably do the whole thing more elegantly with python nowadays.
>
> Maybe someone has a more modern approach? :-)
>
> Duncan
>
>
> On 31/03/2011 22:32, Michael Heeremans wrote:
>>    Hi,
>>
>>    I have a project with a lot of data already loaded. now I would like to
>>    add another seismic survey, but tgis survey has stored its XY
>>    coordinates in a different UTM zone. Any suggestions how I could convert
>>    the coordinates to the 'correct' UTM zone?
>>
>>    Many thanks i advance,
>>
>>    Michel Heeremans
>>
>
>
> _______________________________________________
> Users mailing list
> Users at opendtect.org
> http://lists.opendtect.org/mailman/listinfo/users
>