[PROJ] Patterson projection - supported?

[Even Rouault]

Nyall,

> Does this mean that:
> a. converting the coordinate operation between EPSG:4326 and
> ESRI:54079 to a **proj** string is not supported
> b. creating a coordinate operation for this transform isn't possible at all?

Yes to both. They are strongly related.

The "metadata" part of PROJ lacks currently the mapping between the WKT 
representation of this projection and a corresponding PROJ string. Grepping 
for PROJ_WKT2_NAME_METHOD_ECKERT_I / eck1 in the source tree could likely 
serve as inspiration to find the various locations to patch.

Regarding export to PROJ.4 strings of a CRS definition using this projection 
(to be opposed to building coordinate operation PROJ strings), we should 
probably not do it, because it wouldn't be recognized by the GDAL < 3 
ecosystem.

> 
> Question 2:
> 
> if I try to use gdal/proj master to transform a natural earth dataset
> to ESRI:54079, using:
> ogr2ogr -f "ESRI Shapefile" output.shp ne_110m_admin_0_countries.shp
> -t_srs "ESRI:54079" I only get a bunch of "failed to reproject
> feature" errors.
> 
> Is this expected?

For the impossibility to reproject, yes, given the reasons for the issues of 
Question 1.
For the error message itself, not sure. GDAL might not have all the needed 
clues to issue a more explicit one. I haven't dug.

Even


-- 
Spatialys - Geospatial professional services
http://www.spatialys.com