[PROJ] Motion: promote PROJ 6.3.1RC1 to final release

[Bas Couwenberg]

On 2020-02-12 12:47, Lesparre, Jochem wrote:
> Why aren't the Dutch 2018 grids included?

Because there is no new release of proj-datumgrids-europe yet which does 
include them.

If proj-datumgrids-europe-1.6 gets released the 2018 grids will be 
included.

With the new CDN the regional datumgrid archives are deprecated, so 
there is less demand for the them.

It would be nice to see new regional datumgrid releases along with PROJ 
6.3.1, and for another year or so (assuming there are changes) until 
PROJ 7 and its CDN support is more widely adopted.

> And why aren't at least the
> 2008 grids used instead? It looks like cs2cs EPSG:4937 +to EPSG:7415
> uses no grid at all, but a 7 parameter transformation, introducing
> errors up to 25 cm horizontally and large errors vertically.

If I understand correctly the grids will only be used by cs2cs if they 
are locally available, so you need to have the grids installed in 
PROJ_LIB already.

The first option suggested by projinfo 6.3.1 used the 2018 grids, but 
this may not have been the solution used by cs2cs.

Kind Regards,

Bas