[gdal-dev] gdaltransform user problems

Frank Warmerdam warmerdam at pobox.com
Fri Dec 19 00:41:29 EST 2008

Jack Kirkpatrick wrote:
> Greetings,
> My apologies in advance if the following is stupid but I am not a GIS 
> expert (probably not even a GIS novice).
> Some time ago I had call to transform corner coordinates from 
> "Australian Geodetic Datum 1966" to WGS84 so that I could accurately 
> drape some nautical charts in GeoTiff format onto Google Earth. I used a 
> utility called GEOTRANS2 which produced excellent mathematical results 
> but is decidely clunky to integrate.
> I recently discovered the GDAL utilities and have been trying to 
> replicate this transformation without success.
> ----------------------------
> I have netted down my efforts as follows:
> (1) Environment is Windows XP SP3 and I have installed FWTools 2.2.9.
> (2) I have a file [C:\fwtest\agd66.wkt] containing:
> DATUM["Australian_Geodetic_Datum_1966",
> SPHEROID["Australian National Spheroid",6378160,298.249999999996,
> AUTHORITY["EPSG","7003"]],
> AUTHORITY["EPSG","6202"]],
> PRIMEM["Greenwich",0],
> UNIT["degree",0.0174532925199433],
> AUTHORITY["EPSG","4202"]]


Your WKT file does not have any information on how to transform
from AGD66 to WGS84.  Try using:

SPHEROID["Australian National Spheroid",6378160,298.249999999996,

I got the TOWGS84 values for AGD66 from the geotrans datum list which
is distributed in GDAL as gdal/data/gt_datum.csv.

Best regards,
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent

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