Italy? I am not aware of any Geoid grid file for Italy in PROJ-Data: https://cdn.proj.org/
EPSG:5214 is the vertical coordinate reference system, not a geoid model. https://epsg.org/crs_5214/Genoa-1942-height.html .___ ._ ..._ .. . ._. .___ .. __ . _. . __.. ... .... ._ .__ Entre dos pensamientos racionales hay infinitos pensamientos irracionales. On Mon, 17 Oct 2022 at 10:59, Diogo <di...@photopills.com> wrote: > Hi Andrew. Thanks for taking the time to read my email and reply it. > I'm aware of Copernicus land and other datasets like SMRT3 and ASTER > however I need the best possible elevation resolution available. To do so, > I'm getting the elevation dataset directly from countries geographic > institutes and converting them into the coordinate system 4326+3855. But as > described in my previous email, I'm having some trouble with some geoids. > Do you have an idea why I'm having these transformation issues? To be > honest, I'm a bit lost because I can't understand it. > > Thanks again for your help, > Diogo > > On Fri, 14 Oct 2022 at 15:57, Andrew C Aitchison <and...@aitchison.me.uk> > wrote: > >> On Fri, 14 Oct 2022, Diogo wrote: >> >> > Hello everyone! >> > >> > I'm merging multiple elevation datasets from different countries and I >> > would like to re-project all into the same coordinates system, 4326+3855 >> > using gdalwarp. I'm using `gdaltransform` to confirm that there is in >> fact >> > a conversion from the original projection to the aspected one. However, >> for >> > some datasets, there is only conversion in the XY axis, while the Z >> output >> > is the same as the input. >> >> Is there a good reason to start with these particular datasets ? >> >> There are international bodies who have produced elevation datasets >> covering the whole of >> Europe, eg >> https://land.copernicus.eu/user-corner/how-to-access-our-data >> >> https://www.eea.europa.eu/data-and-maps/data#c0=5&c11=&c5=all&b_start=0&c12=elevation >> >> https://www.eea.europa.eu/data-and-maps/data/copernicus-land-monitoring-service-eu-dem >> >> which would save you trying to stitch together data in different CRSes. >> >> > Below there are some examples (the geoid code is extracted from the >> dataset >> > documentation) >> > >> > Genoa 1942 height (Italy) >> > >> > $ echo "14.995 37.755 3357" | PROJ_NETWORK=ON gdaltransform --debug on >> > -s_srs "EPSG:4326+3855" -t_srs "EPSG:32632+5214">> 1028333.73796622 >> > 4195591.29690422 3357 >> > >> > N2000 (Finland) >> > >> > $ echo "25.15296 62.50195 269" | PROJ_NETWORK=ON gdaltransform --debug >> > on -s_srs "EPSG:4326+3855" -t_srs "EPSG:3067+3900">> 404861.868388335 >> > 6931460.32557422 269 >> > >> > EVRF2007 (Estonia) >> > >> > $ echo "27.059167 57.714444 318" | PROJ_NETWORK=ON gdaltransform >> > --debug on -s_srs "EPSG:4326+3855" -t_srs "EPSG:3301+5621">> >> > 682284.606829111 6401087.4159131 318 >> > >> > >> > I don't have much experience with the projections and I'm a bit lost >> > to understand the possible issues, or interpreted the Z output. What >> > can be the possible issues? >> > >> > Any help would be appreciated. >> > >> > Best regards, >> > >> > Diogo >> > >> >> -- >> Andrew C. Aitchison Kendal, UK >> and...@aitchison.me.uk >> > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/gdal-dev >
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