[Talk-GB] Generating Mapnik Images to epsg:27700 (British National Grid) Projection

Nick Burch openstreetmap at gagravarr.org
Wed Apr 22 12:10:37 BST 2009


On Wed, 22 Apr 2009, Kev js1982 wrote:
> Taking the Eastings/Northings and converting to Latitude/Longitude means 
> they don't quite match (Holyhead ends up around 20km north of it's 
> original location for example) and the tiles don't join properly

Are you aware that WGS84 and OSGB36 use different elipsoids? You'll need 
to change the elipsoid as well as the elipsoid if you want everything to 
work properly. However, the error's normally more like 500m if you forget, 
so I think you might be doing something else wrong if you're out by 
multiple kms.

Alas I can't help on the mapnik side of it

Nick




More information about the Talk-GB mailing list