[Gvsig_english] BIG problems with reprojecting AGD66 to GDA94

[Simon Cropper (Botanicus Australia Pty Ltd)]

Hi Guys,

I am having problems getting the reproject tool to work as expected with 
Australian Projections/Datums.

If I create a shapefile in AGD66 then reproject the file to GDA94 using 
the reproject tool, the points are moved but only ~20m rather than 204 
metres northeast of the original position. If I use the resulting GDA94 
file in the AGD66 View and tell the program, it reprojects on the fly 
and the points overlap.

This shows (a) that the reproject on the fly facility works, and (b) I 
appear to have chosen the wrong projection.

The problem is I have tried reprojecting northing-eastings, 
latitude-longitude, in EPSG and ESRI format but can't get the correct 
reprojection. I have been using EPSG:4202 for AGD66 geographicals, 
EPSG:4283 for GDA94 geographicals, EPSG:20255 for AGD/ AMG zone 55 and 
EPSG:28355 for GDA94/MGA zone 55. I have also tried ESRI: 28355 and 
ESRI:20255 with no luck.

I have even downloaded the transformation grid but not been able to get 
this to work either.

Can anyone help?

Attached is a list of points in a table that are released by the local 
government apparently created by FME. This has the comparable 
coordinates in 4 commonly used projections for 160 distinct points 
across Victoria.

Can anyone get the correct setting and procedure to get these points to 
superimpose when reprojecting on the fly and for the reproject facility 
to work correctly?

I have also included some useful links to help the more industrious and 
knowledgeable to figure out what is wrong.

http://www.land.vic.gov.au/Land/lcnlc2.nsf/LinkView/9B33746B3D77040F4A256A250008E70A5B923E73477D6D65CA256E5F0013D73B

http://www.icsm.gov.au/icsm/gda/gdatm/

http://www.icsm.gov.au/icsm/gda/gdatm/gdav2.3.pdf

Any help would be appreciated as I am trying to tick this off my list of 
things gvSIG can do, and was surprised to see when resulting reprojected 
files were compared to external reference documents they did not align.

Any help would be greatly appreciated.
-- 

Cheers Simon

Simon Cropper
Botanicus Australia Pty Ltd
PO Box 160, Sunshine, Victoria 3020.
P: 9311 5822. M: 041 830 3437.
mailto: scropper at botanicusaustralia.com.au 
<mailto:scropper at botanicusaustralia.com.au>
web: www.botanicusaustralia.com.au <http://www.botanicusaustralia.com.au>

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