geographical accuracy

[Andy Armstrong]

On 21 Feb 2007, at 10:19, Graham Seaman wrote:
> Can anyone with a GIS background tell me if my assumptions are  
> wrong here, and more to the point if there's anything obvious I can  
> do to improve my results?

Geography::NationalGrid::GB uses that NATGRID projection by default  
and you need WGS84 for Google. From looking at the source it looks as  
if you can pass a Projection option to the constructor to specify  
which projection to use. The shift between the two projections is  
certainly about right to account for your error.

Is that reasonable?

Disclaimer: I haven't used Geography::NationalGrid::GB but I have my  
own code that does the same thing.

-- 
Andy Armstrong, hexten.net