[PROJ] transform with external geoid file

[Even Rouault]

Hi Javier,

Le 10/01/2022 à 00:30, Javier Jimenez Shaw a écrit :
> Hi
>
> I want to transform coordinates from CRS A to CRS B in C/C++ with PROJ 
> 8.2.0
> Usually A and/or B are geographic 3D or compound with the geoid file 
> included in PROJ-data. So far so good.
>
> However sometimes one or both systems use a geoid file that is not in 
> PROJ-data. I would like to define de transformation specifying the 
> geoid file(s), and the interpolation reference system(s). How is the 
> best way to do it? Assume that the transformation from geographic to 
> vertical is not defined in proj.db.

Different potential ways:

- use a manually built PROJ pipeline

- use WKT string with BoundCRS (but I don't think you can control the 
interpolation CRS that way)

- use proj_create_vertical_crs_ex()

- add new grid_transformation records in proj.db or an auxiliary DB

Even

>
> Thanks
> Javier
> .___ ._ ..._ .. . ._. .___ .. __ . _. . __..  ... .... ._ .__
> Entre dos pensamientos racionales
> hay infinitos pensamientos irracionales.
>
>
> _______________________________________________
> PROJ mailing list
> PROJ at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/proj

-- 
http://www.spatialys.com
My software is free, but my time generally not.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/proj/attachments/20220111/4e0eb713/attachment-0001.html>