Geo::Coordinates::OSGB
Geo::Coordinates::OSTN02
------------------------

Routines to convert latitude and longitude coordinates to and from transverse
Mercator grid references. The routines are optimized for use with the British
national grid.

The OSGB module provides routines to convert between latitude/longitude
coordinates based on the British Ordnance Survey's standard geoid model and
the British National Grid.  The module includes some useful extra routines to
parse and format grid references in a variety of popular forms (including
which Landranger map your point appears on).

The second module provides an implementation of the standard transformation
tables that are now used by the British Ordnance Survey to define the
National Grid from GPS surveys.  This module provides accurate conversion
between the British National Grid and latitude/longitude coordinates based on
the global WGS84 geoid model (the one used by all GPS devices, and popular
mapping tools such as Google Earth).  The OSTN02 data is rather large (6M
bytes), and will take a few microseconds to load even on a new machine,
but once loaded conversions should be reasonably quick.

Note that due to the nature of this type of conversion, the conversions are 
only really useful in the vicinity of the British Isles.  If you are elsewhere 
on the planet you need an implementation optimized for your neighbourhood.
Some suggestions for how to adapt the routines for use elsewhere are included
in the documentation.

INSTALLATION

This package installs in the regular Perl way.  You don't need the C compiler
and as far as I know there are no platform dependencies.  Either use your
local package tool, or just try

  [sudo] perl -MCPAN -e "install Geo::Coordinates::OSGB" 
  
For the die hards, the package can also be installed by
hand; just unzip it to some temporary home, then do the usual thing:

        Perl Makefile.PL
        make
        make test
        [sudo] make install

The last tests called by "make test" *will* generate some harmless warnings.
The full suite of tests takes less than 2 seconds on my machine. 
You may or may not need sudo depending on how you have set up your system.

DEPENDENCIES

None.

COPYRIGHT AND LICENCE

Copyright (C) 2002-2015 Toby Thurston

OSTN02 transformation data is freely available but remains Crown Copyright (C) 2002

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.

All feedback gratefully received.