OS MasterMap® at EDINA

Tuesday 4 September 2007 saw the long-awaited release of Ordnance Survey's OS MasterMap® data to all institutions subscribing to the Digimap Ordnance Survey Collection.

After the lengthy and complex production of a data delivery mechanism and the integration of the new data into the existing online mapping tools (a process spanning a period of 18 months), staff and students now have the opportunity to gain from the benefits that OS MasterMap offers:

features with a unique identifier through which other data can be associated
area features representing individual real-world objects such as buildings, orchards and lakes
seamless data rather than a file-based dataset of fixed tiles.
a new and better system of feature classification
greater control over the data users can download

Digimap now offers two OS MasterMap Layers, each of which offers different views on the landscape of Great Britain:

The Topographic Layer contains more than 450 million uniquely identified geographic features, and provides highly detailed data about natural and man-made features within Great Britain at scales of 1:1250 1:2500 and 1:10 000 and is created from a master database which is refreshed every six weeks.
The Integrated Transport Network (ITN) Layer offers a national definitive digital map for Great Britain's road structure, including comprehensive routing, restriction and advisory route information.

Land-Line.Plus to Topographic Layer

OS MasterMap Topographic Layer is the replacement dataset for the popular Land-Line.Plus® dataset (which accounted for around 45% of the approximately 560,000 OS data files downloaded from Digimap over the past 12 months), which Ordnance Survey recently announced will be withdrawn on 30 September 2008.

Although Digimap will continue to deliver Land-Line.Plus data through the usual Data Download facility until August 2008, the data available is dated July 2006, and will therefore be increasingly out-of-date.

We recommend that users move to the OS MasterMap, particularly if more up-to-date data is required.

EDINA will be regularly receiving updated OS MasterMap data from Ordnance Survey, and has designed the data supply facility so that users, after taking a full initial supply, can just download the data changes for the area they are interested in rather than a complete re-supply. Using this, they can build historical records of change.

EDINA will also archive the data so that at some time in the future users can obtain historic views of OS MasterMap data.

Data Tools

OS MasterMap data are available through a new online facility within Digimap called MasterMap Download, which enables you to select any rectangular area covering the appropriate area of interest, since OS MasterMap is a seamless database; you are no longer constrained by the notion of data tiles which each cover a fixed area.

You can also select individual themes of data rather than the whole layer. For example, if your research requires only details of building outlines, you can choose to download only the Buildings theme from the Topographic Layer.

Mapping Tools

As well as a new data supply facility, the mapping tools have also been modified.

Classic and Carto both now display OS MasterMap maps where previously they displayed Land-Line.Plus maps.

However, in both mapping facilities there is the option to convert the maps from full colour to line drawing style. (See the maps on this page.)

Those used to the Land-Line.Plus 'look' or who use the maps to compare with earlier OS maps, will appreciate this additional function.

Continuous Improvement

EDINA will monitor the uptake and use of these new datasets, and identify improvements to the service so that it continues to meet the needs of users as their experience of OS MasterMap matures.

Digimap website