[OpendTect_Users] GNSS coordinates, Decimal degree

[Bert Bril]

Hi all,


I see nobody responding, so here's my $0.02 on it. Maurizio wrote:

> I can export directly UTM coordinates from my acquisition software with
> a cm/mm resolution, but then I can't import e.g.
>
> 0    607778.360    4404971.106    33S    384.77

This is a matter of making a small script to convert to what is 
required. For 2D, you need to make a file that OpendTect can load - with 
trace number and coordinates, like:

101 607778.3 4404971.1
102 607780 4405001.4

Note that you only need to put bend points in the file (OpendTect will 
inter- and extrapolate).

For 3D data, you can only use the 'manipulate' tool to construct your 
coordinates from anything that is available in the headers. Besides, the 
Rev.1 specification says the inline/crossline number is mandatory. So 
you can simply set up the survey's coordinate vs inline/crossline system 
and then import using inline/crossline as the key. OpendTect will 
generate the coordinates


> Dr. Julien Moreau highlights the real problem, I think..thanks.
>
> A Odt tool (the 2D geometry works in this way?), that allows to directly
> load the coordinates from the ascii files,

Which is there, for 2D data. You have to un-check the 'X-coordinate 
byte' checkbox, then you get a choice on how the coordinates should be 
defined. If the line's a straight line, then you can simply define that 
without any coordinate file.


> could be really useful and it
> can be a simple solution to that problem (e.g. also using a scalar like
> 1000). In this way, you could import the coordinates in Odt without
> directly read into the SEG-Y file...also in the case of numerous and
> long 2D lines and/or 3D GPR volume.

If you can make any file you want, I'd always go for the 'Simple file' 
format. Make an ASCII file with every trace on one line, like:

101 607778.3 4404971.1 sample sample ...
102 607780 4405001.4 sample sample ...

It's simple to make, and you can QC and edit with any good text editor.


/Bert

-- 
-- Bert Bril / OpendTect developer at dGB
-- mailto:Bert.Bril at opendtect.org , http://opendtect.org