Hi Jane
Some points from a few years of running geocoded archive records over map / GIS interfaces:
1; provide users a way of simply picking the co-ordinates from a map - open source interfaces like OpenLayers can do this
2; if you get a National Grid Reference from Ordnance Survey be aware of the 'derived from OS' licence issues if using commercially
3; choose one co-ordinate system and then convert to the other at data entry / index time rather than trying to re-project at display time.
4; we've found encouraging accuracy (to a building level) means more useful geocoding (in terms of apps etc), than just to the centre of Manchester
Unless you are specifically using Ordnance Survey to MasterMap scales of presentation, I'd recommend WGS84 , especially as organisations like National Library Scotland [1] have
re-projected the historic OS to world co-ordinates so that it can be used over the likes of Bing satellite etc
All best
--
James Grimster
Orangeleaf Systems Ltd
[1] http://maps.nls.uk/os/
On 8 Dec 2014, at 10:27, Jane Stevenson wrote:
> HI David,
>
> Right, so ‘WGS84’ or ‘OSGB36’ kind of refers to the shape of the earth…which seems very profound!
>
> I guess I just wanted an option for including coordinates for latitude and longitude as well as place names as index terms, and I thought it would be good to specify the system used (...the theoretical shape of the earth used). As has been pointed out, if an archivist wants to refer to Manchester, then whichever system is used shouldn’t be an issue, but if they want to refer to 84 Plymouth Grove, Manchester, home of Elizabeth Gaskell, then maybe there would be a difference. But until I started thinking about this more, I had no idea that you could get different coordinates depending on the system you use, so I don’t suppose most archivists will be thinking of this. If I provide the option to specify WGS84 or OSGB36 I’m not sure people would know what it means.
>
> cheers,
> Jane
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