[PROJ] WKT1 Vertical Perspective CRS regression

Even Rouault even.rouault at spatialys.com
Mon Dec 28 08:47:51 PST 2020


Jonathan

This is a side effect of https://github.com/OSGeo/PROJ/pull/1971

The past mapping of ESRI:54049 to the below WKT was incorrect. GDAL 2.4 (which 
is what WKT1_GDAL means) has never recognized the nsper projection. If you 
tried the below WKT with it, it would fail.

You have to use WKT2 with that projection.

I tried quickly with GDAL (master and 3.2 branch) to reproduce the issue by 
doing in Python

from osgeo import osr
sr = osr.SpatialReference()
sr.SetFromUserInput('ESRI:54049')
sr.AutoIdentifyEPSG() (which calls GetEPSGGeogCS())

but I couldn't reproduce any error when doing so.

Even

> Hi PROJ list,
> 
> I'm not sure which list to report this since my initial issue was expressed
> through GDAL, but since the issue is reproducible in PROJ alone, I'll start
> here.  I've encountered a regression upgrading from PROJ 6.2.1 to 7.2.0
> when using GDAL's GetEPSGGeogCS with the Vertical Perspective CRS expressed
> by ESRI: 54089. Based on an initial investigation, I think the issue is in
> WKT1:GDAL generation.
> 
> Using PROJ 6.2.1, I can do the following:
> 
> projinfo ESRI:54049 -o WKT1:GDAL
> WKT1_GDAL:
> PROJCS["World_Vertical_Perspective",
>     GEOGCS["WGS 84",
>         DATUM["WGS_1984",
>             SPHEROID["WGS 84",6378137,298.257223563,
>                 AUTHORITY["EPSG","7030"]],
>             AUTHORITY["EPSG","6326"]],
>         PRIMEM["Greenwich",0],
>         UNIT["Degree",0.0174532925199433]],
>     PROJECTION["Vertical_Near_Side_Perspective"],
>     PARAMETER["False_Easting",0],
>     PARAMETER["False_Northing",0],
>     PARAMETER["Longitude_Of_Center",0],
>     PARAMETER["Latitude_Of_Center",0],
>     PARAMETER["Height",35800000],
>     UNIT["metre",1,
>         AUTHORITY["EPSG","9001"]],
>     AXIS["Easting",EAST],
>     AXIS["Northing",NORTH],
>     AUTHORITY["ESRI","54049"]]
> 
> But in PROJ 7.2.0, I get the following:
> 
> projinfo ESRI:54049 -o WKT1:GDAL
> WKT1:GDAL string:
> Error when exporting to WKT1:GDAL: Unsupported conversion method: Vertical
> Perspective
> 
> 
> I'm aware of release notes for GDAL that impacted Vertical Perspective (and
> I haven't found any corresponding in PROJ), but I suspect the GDAL issue is
> rooted in PROJ too.
> 
> 
> Thanks,
> Jonathan


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