Dear All,
There are obviously a variety of issues regarding EDINA Digimap coming up
on these mail lists which I will deal with in this and subsequent e-mails.
Dealing with Kathryn's comments first...
>A few thoughts:
>One disadvantage with Edina Digimap data is that there is no historical
>mapping. If we stop buying paper maps and rely on Digimap we will only have
>access to this year's mapping not any previous years. So there will be no
>historical collection growing over time. The only solution is to buy the
>data directly from OS, much more expensive than paper maps.
EDINA is aware of this issue and has been looking into it for some time.
1) The Digimap.Plus Project (the R&D wing of Digimap) is working on a pilot
service to
provide access to historic OS large-scale maps i.e. Ordnance Survey 1:10
560/1:10 000 scale and 1:2500 scale County Series and superseded National
Grid mapping supplied through the Landmark Information Group Ltd. This
pilot service, which comprises data for Edinburgh and Newcastle, should be
available to six trial University sites in early February - later than we
wanted but trying to build a seamless database of this data has been
technologically challenging (we have been using MrSID and are not so
enamoured with it as some of the other contributors to this list). If the
trial proves successful i.e. demand is shown to exist for this data, EDINA
will be talking to JISC about the possibility of a national service. We
would hope that such a service would provide access to maps for the period
1843-1945+.
Before anyone responds by pointing out the existence of
http://www.old-maps.co.uk/ (and online access to 1:10560 scale maps) let me
say that it is our intention that the final service would allow you to view
maps from all the different periods (epochs)and scales, side by side and
alongside current OS data.
2) You may perhaps have noted that OS do not provide access to earlier
versions of their digital map data. (Try calling them and asking for copies
of Land-Line data for 1996.) It is in fact a technically difficult thing to
do requiring huge amounts of disk space. The OS DNF provides a way forward
for large-scale mapping because it will allow the identification of change
between time periods and one can then potentially keep a historic record of
an object - at the moment all one knows is that a particular Land-Line
tile has changed even though only a few objects within that map tile may
have changed.
We are currently drafting a proposal to submit to the JISC for funding to
look at the implications of DNF for Digimap (significant). Part of the
proposal is entitled 'Change over time' and will look at how we could
modify the service to make use of the improvements in the DNF so that, for
example, a student working in a project in 2004 could make a map of part
of, say, Oxford as it was in 2001. At the same time we will look at
providing users with the ability to download earlier versions of the NTF
and DXF data. Whether EDINA should become a on-line 'archive' for OS
digital map data is something that is not clear at the moment - it would
certainly have financial implications for the JISC and remember that EDINA
is only funded by the JISC to provide access to OS data until 2004.
>Digimap Carto needs to get online before we can assess how useful Digimap is
>really going to be for the average student with no specialist GIS knowledge
>but who just 'wants a map'.
Digimap Carto is not aimed at the average student. For the student who just
wants a map, we recommend they use the basic mapping tool. Digimap Carto is
aimed at the more advanced user, by offering them increased functionality;
someone who, for example, understands the concept of scale. We welcome
suggestions on how the basic mapping tool might be improved. The next
version will include a place name search facility, similar to Get-a-map. In
the future we would hope to add postcode searching as well.
>Postcode maps would be very useful. UK Borders 'sort of' does this but not
>really, unless things have changed since I last looked.
UKBORDERS was first released in 1995. Development funding from the ESRC was
frontloaded and EDINA have been therefore hampered in developing a web
mapping capability. We are currently seeking funding to add such a
capability. One possibility is for UKBORDERS to be linked to Digimap. Users
would then be able to overlay postcode areas on top of Land-Line maps.
Would that be something people would be interested in us doing?
>Any chance of BGS data!?
Good idea!
>With more Universities joining up, can we negotiate for more than 33% of the
>UK? I bet a lot less than 33% is chosen because we want to hold some tiles
>in reserve for unexpected major projects. Alternatively, could we have a
>swapping system for tiles and deselect ones we have finished with and choose
>alternatives for new projects?
I think we all agree that the 30% limit is a major handicap and is
hampering both the uptake of the service and service development. We are
also aware that it is an administrative headache for subscribing sites and,
to be honest, we would prefer spending our time improving the service
instead of managing the tile selection process. (For those not aware of the
issue, JISC had insufficient funds available to secure access to all
229,000 of the Land-Line.PlusŪ tiles, therefore the agreement between
Ordnance Survey and JISC specifies that no more than 30% of the
Land-Line.PlusŪ tiles may be available for digital mapping or data download
in any given academic year.) It is interesting to note however that during
the first academic year of the service, a total of 62,100 Land-Line tiles
were selected, and of these only 28,353 were used within the service. On
every possible occasion EDINA raises the issue with OS and JISC. We can
only hope that the meeting between OS and JISC in the spring produces
something.
David Medyckyj-Scott
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Dr David Medyckyj-Scott
EDINA Service Manager,
Research and Geo-data Services Team
Data Library
Edinburgh University
Main Library Building
George Square
Edinburgh EH8 9LJ, Scotland
tel: +44 (0) 131 651 1308 fax: +44 (0) 131 650 3308
Email: [log in to unmask]
URL: http://edina.ac.uk/
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