[postgis-devel] transforming coordinates in postgis

[Mark Cave-Ayland]

Aengus McCullough wrote:

> Hi,
> I am having difficulty transforming coordinates from EPSG:4326 to EPSG:27700 in POSTGIS.  The transformation executes successfully but is out by 100m in the Easting and 60m in the Northing.  Is this likely to be an error in the transformation parameters defined in the spatial_ref_sys relation?
> 
> Given the original coordinate in SRID 4326:   55.001428, -1.614208, when I run 'transform(geom,27700)' I get the result: 424687.13, 567430.91
> This is substantially different from the converter on the Ordnance Survey website and the transformation functions in geotools.  Help! What am I doing wrong?

Hi Aengus,

Yeah this is a known issue - see 
http://postgis.refractions.net/pipermail/postgis-users/2008-October/021639.html 
for a solution.


HTH,

Mark.

-- 
Mark Cave-Ayland
Sirius Corporation - The Open Source Experts
http://www.siriusit.co.uk
T: +44 870 608 0063