Well I’ve been away from this blog for awhile, please accept my apologies, life it seems can get in the way (and I’m glad it does!).   So today’s post on the Ordnance Survey blog finally starts to answer some of the frustrating things about Geographic data in the UK.

The Ordnance Survey is a great organisation that creates what I think of as the best paper mapping product anywhere, both in terms of looks and accuracy.   Other countries I’m sure look at the UK and its quality of mapping with envy.   However there is a little stain on this mapping perfection and that is licencing and something called derived data (see bottom of this article).

Working for local planning authorities I always wanted more access to data and to access it my way.   As a planning officer Google Earth/Maps was great and if only StreetView was available to me as well….   One of my roles in one authority I was working at was to develop the front facing planning pages (as well as coordinate the back office).   Forget text searches, I wanted maps!   Asking IT whether I could do something always started with a cost implication and then a licensing implication.  It was here I learnt that some of the data that the OS relied upon for its maps was collected by Local Authorities who then had to buy back their mapping (as MasterMap), think address points, new developments, rights of way maps etc…
So this new post on the OS blog (What the PSMA really means) offers us all some light at the end of the tunnel, and I think regarding derived data, we may see some kind of happy compromise in regards to public use of locally held data like Rights of Way mapping, for PSMA stands for Public Sector Mapping Agreement.

“all organisations will have access to the same data meaning there will be no disparity between the datasets available to those in Central and Local Government and Health”


So, let’s be clear. Under the terms of the PSMA, all 800 members will be able to share Ordnance Survey data, and data derived from it, with any other organisation as part of their ‘core activity’.
This is basically the framework that exists under the current Pan Government Agreement (PGA) today.
For example, the Rural Payments Agency uses OS MasterMap to help it calculate the grants owed to farmers. As part of that job (or ‘core activity’) they can freely share that data with the farmers they are working with, even though the farmer is not a PGA member themselves.
This principle will also extend to organisations that want to publish key information online, like the location of public amenities, using a web mapping API.

Lets hope Local Authorities now act on this new agreement and encourage its residents to access their geographic data and create new ways of using it.   You never know this might be a cost saving for local authorities!

Not Sure what “derived data” is? Well here is the an extract from The Guardian that might help shed light :

Q What constitutes data ‘derived’ from Ordnance Survey data?

A Simply put, Ordnance Survey derived data is any data created using Ordnance Survey base data. For example, if you capture a polygon or a point or any other feature using any Ordnance Survey data, either in its data form or as a background context to the polygon/point/other feature capture, this would constitute derived data.

This is often an eye opener to people, Local Authorities are afraid of sharing data sets like Rights of Way maps, that they themselves create maintain and actually keep open on the ground physically!   The OS has in the past claimed ownership (and may still do) of these maps and then sold them back to the Local Authority!  All because the Authority uses an OS basemap.  

OS Blog post : http://blog.ordnancesurvey.co.uk/2010/08/what-the-psma-really-means/
Update: New post at Knowhere bloghttp://knowwhereconsulting.co.uk/how-complex-can-this-derived-data-thingmy-be/