search

OSGeo / PROJ-data

Repository for proj datum grids (for use by PROJ 7 or later)
Other
72 stars 33 forks source link

Add SAGEOID2010, South African geoid #73

Closed jjimenezshaw closed 2 years ago

jjimenezshaw commented 2 years ago

Grid file for South African geoid model, from ITRF2005 to SA LLD height

See related PR https://github.com/OSGeo/PROJ/pull/2906

Produced with this script:

echo "$(echo 'lat long alt' | cat - SAGEOID2010.dat | sort -u -k1,1nr -k2,2n)" > SAGEOID2010.dat  # add the header line and sort by latitude N-S, then longitude W-E

docker run --user $(id -u):$(id -g) --workdir $PWD \
             --rm -v /home:/home osgeo/gdal:alpine-normal-latest python3 ./PROJ-data/grid_tools/vertoffset_grid_to_gtiff.py \
             --type GEOGRAPHIC_TO_VERTICAL \
             --source-crs EPSG:7910 \
             --target-crs EPSG:9279 \
             --area-of-use "South Africa" \
             --copyright "Derived from work by CD:NGI. CC BY 4.0 https://creativecommons.org/licenses/by/4.0/" \
             SAGEOID2010.dat za_cdngi_sageoid2010.tif
rouault commented 2 years ago

"Geotransform with a positive pixel height, that is a south-up image, is supported, but a unusual formulation" ==> using gdalwarp could help producing a north-up image

jjimenezshaw commented 2 years ago

producing a north-up image

I reordered the input file, that had to be modified anyway to add the header. I hope it is now Ok. The generation script is in the PR description.

jjimenezshaw commented 2 years ago

@rouault Is the order correct now? It is now "ready for review"