BUG epsg 31253 WRONG towgs84 transformation parameters

[proj4-bot]

Reported by mdiener on 26 Jan 2015 07:19 UTC
proper settings should be for EPSG 31253, 31252, 31251
+towgs84=577.326,90.129,463.919,5.137,1.474,5.297,2.4232

I have contacted the ESPG.org people and Roger Lott repsponded with this great email...see below

A brief technical summary:

     EPSG::31253 is a projected CRS for (the eastern part of) Austria.

     The transformation with parameter values 682,-203,480 is a transformation from the US National Geospatial Intelligence Agency (NGA). We carry this in the EPSG Dataset as EPSG::3962. It is  applicable to former Yugoslavia. It is not applicable to Austria.

     The transformation with parameter values 577.326,90.129,463.919,5.137,1.474,5.297,2.4232 is an official transformation from the national mapping agency of Austria. We carry this in the EPSG Dataset as EPSG::1618. For anyone defining early binding strings it is appropriate to define it with CRS EPSG::31253, as well as with EPSG::31252, EPSG::31251 and others.

     As a matter of principle transformations should only be applied to areas that fall within the area of intersection of their source and target geographic CRSs. EPSG supplies polygons describing these areas. Had these been used in the construction of the proj.4 string it should have been seen that the area associated with CRS 31253 (EPSG polygon code 1708) and the area associated with transformation 3962 (EPSG polygon code 2370) do not intersect, so the two should not have been bound together.

If you think it will help feel free to copy this message to them. Roger Lott, IOGP Geodesy Subcommittee

Migrated-From: https://trac.osgeo.org/proj/ticket/254

[proj4-bot]

Modified by mdiener on 26 Jan 2015 07:19 UTC

[rouault]

Fixed in https://trac.osgeo.org/geotiff/changeset/2748

Updated epsg file will come with EPSG v9 upgrade: #477