[Gdal-dev] problems with datum transform AGD66 to GDA94

[Michael Sumner]

Thanks Andrew, 

That's what I thought - but the differences between the GDAit and ogr2ogr 
conversions are 100-200m. 

That is worse than I thought we could expect. I simply don't know how
else to specify the conversion for this transformation. 

Cheers, Mike.

>Mike,
>Based on your DSE link, one of the things you may be missing is that
GDAit is using a >local grid distortion model as well as doing a point to 
point conversion from AMG to MGA. >The local distortion model uses a grid 
of observed values to determine additional local >shifts. GDAit is
considered the most correct conversion for AMG to MGA and depending on
>location this can be a metre in magnitude.