[Gdal-dev] issue warning to user when performing datum shift (OGR, GDAL)

[Dylan Beaudette]

Hi everyone,


In light of some recent thought, experimentation, and discussion [1] I
am wondering if it would be at all possible or even desirable to warn
the user when a datum shift operation is about to be performed. Within
the US, and assumming that the NADCON grid was installed with Proj4,
transforming between NAD27 and NAD83 should work just as expected.
However, in other parts of the world, this may not be the case.
Therefore, it might be a good idea to follow the model used in GRASS,
where the user is specifically prompted for datum transform parameters
whenever defining a new locatio, in these situations.

Any thoughts / reasons not to do this?

Cheers,

1. http://casoilresource.lawr.ucdavis.edu/drupal/node/259


Dylan