[GRASS-user] Little experiment: comparison of vector projection OGR and ArcGIS

[Dylan Beaudette]

A while back I was wondering if ArcGIS and OGR would produce the same
output from the same projection operation...  Results where identical
for operations within the same datum, using a GCS -> UTM projection.

A couple days ago I did another experiment, this time incorporating a
datum shift: GCS NAD83 --> UTM NAD27. I have summarized the results
here:

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

of note:

- the default tranform in ArcGIS does not produce the correct results.
- the 'NADCON' transform in ArcGIS produces the same results as OGR.


Any comments on some of the questions posed are welcomed.


Cheers,

Dylan