Levelling
of Great Britain
[2GL Transcription]
|
Ordnance Survey's Levelling of Great Britain |
[2GL Abstract] [2GL Transcription] |
|
If you haven't already seen then the 'What's New for November' :
http://www.deformedweb.co.uk/trigs/news-Nov04.html
then
that's a good place to start as not much has happened for December yet (I've
been away for much of it).
Anyway here goes as a general overview of
recent developments:
----------------------------------
The
main development has been the sourcing of a Abstract of Secondary Levelling
lines in Greater London.
http://www.deformedweb.co.uk/trigs/data/SL_London/
This
includes many S plates in the London area, its in a similar format to Primary
Network, i.e. text descriptions of locations, so there's a plotting exercise
there if anybody is interested!
----------------------------------
We have also recently obtained permission to display some plates from OS
annual reports. These depict the progress of re-levelling in the 50/60's at a
National scale. Of interest is that Secondary lines are also depicted on some,
(unfortunately not very accurately)
http://www.deformedweb.co.uk/trigs/annual.cgi
Someone
might be able to turn these into a nice animation of progress over time?
----------------------------------
The new location search (
http://www.deformedweb.co.uk/trigs/lll.cgi
) has been used to spot a few mistakes in various databases.
I have also
started adding some non FB/Pillar related datasets to this page which might be
of interest (shameless plug ;-), e.g. Megaliths, Milestones, Geocaches, Hills,
and Radio Transmitters.
----------------------------------
Hot
off the press is that I've just updated the script to compile combined lists of
FB number locations:
http://www.deformedweb.co.uk/trigs/fbsdb.cgi
you
can now filter what you want to download. This also give the script some use in
comparing databases.
----------------------------------
The
interactive map has got a lot more possible layers:
http://www.deformedweb.co.uk/trigs/go/ExampleMap
it now includes Primary, and Secondary Trigpoints, Triangulation Secondary
Blocks, LR and Exp Maps outlines. (The mapping is also used by the Location
search above, so from there can display its various datasets overlaid on the
map)
The base mapping has got a lot more detailed in that we now
display a better coastline, and show Urban Areas, A roads, Motorways, Railways
and Rivers. (this has reminded me that the Key is BADLY in need of updating ;-)
- the accuracy of these datasets should be able to improve. (does
anybody have access to a Batch NAD27 to OSGB converter?)
----------------------------------
If anybody has any questions on
any of these then either reply or email me directly. Special Thanks as always
to Ian Richardson, Rod Sladen, Graeme and Rob Woodall, for their help with
these pages. (in fact much of the sourcing of the data has been by Ian
Richardson)
Best regards,
Barry