We have the same problem here, It tends not to look too bad in rural
areas but all the listed buildings in Chipping Sodbury moved 2m to the
left.
According to our GIS team (more Cincinnati Bengals than Tampa bay
Buccaneers) they and the OS are looking into the problem, however I know
that MapInfo (our GIS) have some tools for doing this but they cost
money! At the moment with restricted access to the mapping I have tended
to ignore the problem, but suspect that I will have to go through all
the sites.
Master Map the new OS base has polygons for building instead lines so
if your polygons are accurate it should not be too difficult to re-snap
them to the revised polygons,
Thank you
David Evans
Historic Environment Record Officer
01454 863649
>>> [log in to unmask] 07/10/2003 11:36:05 >>>
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/
> +++++++++++++++++++++++++++++++++++++++++
>
>
**********************************************************************
This email and any files transmitted with it from South
Gloucestershire Council are confidential and intended
solely for the use of the individual or entity to whom they
are addressed. If you have received this email in error
please notify the South Gloucestershire Council
Postmaster at the address below.
This footnote also confirms that this email message has
been swept for the presence of computer viruses.
[log in to unmask]
**********************************************************************
|