[Gdal-dev] NAD83 vs. WGS84

[Grabowski, Hank]

The problem as I've determined is that my "NAD27->WGS84" conversion is
really just doing a "NAD27->NAD83" conversion.  The NAD27->NAD83
conversion in ESRI identically matches the conversion I'm attempting in
OGR.  Is there something wrong with the syntax of my command for the
conversion to WGS84?  

ogr2ogr -t_srs WGS84 out.shp roads.shp

My program's internal conversion to WGS84 has the exact same difference,
so I figure once I determine how to get the conversion working in
ogr2ogr I should be able to map it over to my internal code as well.  Is
it such that NAD83 is the best I can do with OGR? If that's the case
that's fine.  I just need to make that fact known to our users.

Thanks for the help guys, you've all been very responsive.
Hank