Dear all
In Gloucestershire we have just been made aware (communication is not a high
priority here) that some of our OS base mapping has been updated and shifted
anything up to 5m by the OS positional accuracy improvement programme. This
process was started in 2001 and has now covered about a quarter of the
county. We are in position where some of our polygons are accurate (ie those
digitised after 2001) but sit alongside others that are not accurate because
the base mapping has shifted. I am tempted to take the view that the data
was digitised at 1:10,000 and is inaccurate anyway so I may as well leave it
but the problem becomes too big to ignore in urban areas where the polygons
were (generally) more accurately digitised.
I know that a decent GIS (unlike ours) would be able to rubber-sheet the SMR
data to take account of the changes but I would be interested to know how
others are dealing with the issue?
All the best
Tim
> +++++++++++++++++++++++++++++++++++++++++
> Tim Grubb - SMR Officer
> Gloucestershire County Council Archaeology Service
> Environment Dept.
> Shire Hall
> Gloucester
> GL1 2TH
>
> Tel: (01452) 425705
> Fax: (01452) 425356
> Email: [log in to unmask]
> Web: http://www.gloscc.gov.uk/archaeology/
> +++++++++++++++++++++++++++++++++++++++++
>
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