[OSGeo-UK] OSGB36 WGS84 conversion problem

[John A Stevenson]

Hi,

I have been using GRASS GIS, which uses Proj4 to convert between 
projections.  I have data in OSGB36 projection (a Nextmap DEM and a 
scanned in OS map), and I am trying to merge it with GPS data (from 
WGS84).  When I do the conversion (using EPSG:27700) I find that the GPS 
data plot about 100 m east of where they should do.

Has anyone else had this trouble converting between OSGB36 and WGS84 
coordinate systems?  What is the solution?  Are there any other 
conversion parameters available?

Cheers

John

-- 


Dr John Stevenson
Postdoctoral Research Associate
School of Earth, Atmospheric and Environmental Sciences
Williamson Building (Room 2.42)
University of Manchester
Manchester M13 9PL, UK
tel. +44(0)161 306 6585; fax. +44(0)161 306 9361;
john.stevenson at manchester.ac.uk