Geo::Coordinates::OSGB(3pm) on Linux
The text 202f55e429c6, as Debian 8 (Jessie) shipped it.
Convert coordinates between Lat/Lon and the British National Grid An implementation of co-ordinate conversion for England, Wales, and Scotland based on formulae published by the Ordnance Survey of Great Britain. These modules will convert accurately between an OSGB national grid reference and lat/lon coordinates based on the OSGB geoid model. (For an explanation of what a geoid model is and why you should care, read the Theory section below.) The OSGB geoid model fits mainland Britain very well, but is rather different from the international WGS84 model that has rapidly become the de facto universal standard model thanks to the popularity of GPS devices and maps on the Internet. So, if you are trying to translate from an OSGB grid reference to lat/lon coordinates that can be used in Google Earth, Wikipedia, or some other Internet based tool, you will need to do two transformations: first translate your grid ref into OSGB lat/lon; then nudge the result into WGS84. Routines are provided to do both of these operations, but they are only approximate. The inaccuracy of the approximation varies according to where you are in the country but may be as much as several metres in some areas. To get more accurate results you need to combine this module with its companion Geo::Coordinates::OSTN02 which implements the transformation that now defines the relationship between GPS survey data based on WGS84 and the British National Grid. Using this module you should be able to get results that are accurate to within a few centimetres, but it is slightly slower and requires more memory to run. Note that the OSGB (and therefore this module) does not cover the whole of the British Isles, nor even the whole of the UK, in particular it covers neither the Channel Islands nor Northern Ireland. The coverage that is included is essentially the same as the coverage provided by the OSGB "Landranger" 1:50000 series maps.