Coordinates are off when viewed from Google

[ivorw]

Google Maps has highlighted that the Lat/Long coordinates are offset from the maps.

see The Millenium Dome, for an example: http://www.nurflax.net/cgi-bin/openguides/wiki.cgi?action=index;format=map&long=0.006849&lat=51.503005&zoom=1

[bob]

isnt this just an effect of the fact that the page has the wrong coords anyway.

[ChristopherSchmidt]

London for a long time used a manual converter from OS X/Y coords to GpS Lat/Lon. This converter used Airy projection. Google Maps uses WGS-84 projection. Although one may be more accurate on the actual planet or somethign (I don't know) many of London's points will not map properly onto Google Maps because of this.

[anonymous]

As will be included in documentation when the google maps stuff is properly released, there are fudge factors involved at present. I'll include conversion code so that non-wgs84 stored data can be used with google maps.

That said, guides getting lat/long data (rather than os coords) directly from users need to check their data for consistency anyway, and also define what their stored data will be in the edit form.

[dom]

(that last was me, sorry)

[nick]

This should now be fixed, if you have the latest OpenGuides, Geo::HelmertTransform? installed, and you have the following options set:

geo_handler = 1 force_wgs84 = 0

(Any data where you entered a lat/long, and it was badly converted to easting+northing, will still be wrong. However, any entered as a correct easting+northing will work)