[Qgis-user] NTv2-transformation: different output values in QGIS and GDAL

[andy]

Hi Even,

On Tue, 16 Jan 2024 at 13:14, Even Rouault <even.rouault at spatialys.com>
wrote:

> Did you try with the full path
> +nadgrids=C:\OSGeo4W\share\proj\ItalyED50toWGS84_NTV2_GN.gsb ?
>

Yes, and I had the same problem.

I have solved upgrading to 3.28.14.
But I don't have what Totò wrote, it doesn't ask me to install anything.
But I have the same output coordinates as gdal.


> But, what is the history of this "ghost" grid that requires fetching it
> from web.archive.org ? Has it had some official status, and could it be
> provided under an open data license ? If so, it would be great if Italian
> authorities could register to IOGP/EPSG this grid for ED50 -> WGS 84 for
> Italy... Then we could ship it in PROJ-data.
>
> But I remember complicated discussion at FOSS4G Firenze with the guys from
> the geodetic authority (https://www.igmi.org).... Not sure if that has
> lead to anywhere.
>
Italy is not a good country:

- cadastral data are not open (we only have open a not very useful WMS);
- the Italian post codes polygons are not open;
- we do not have official grids open.

I'm using the gsb file created from the great Ernesto Sferlazza [1].
IGMI believes that it should not apply open data laws to this very general
interest data. I do not know the reasons for this choice.

Thank you Even an Totò

[1]
https://www.provincia.agrigento.it/flex/files/D.269115642901971a8757/generazione_ed_utilizzo_delle_griglie_NTV2.pdf

-- 
___________________

Andrea Borruso
website: https://medium.com/tantotanto
38° 7' 48" N, 13° 21' 9" E, EPSG:4326
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