Data collection, management and analysis

Ordnance Survey’s data gives the most accurate and current view of Great Britain. We own the National Geographic Database (NGD) which holds around 500 million features.

Any changes to natural, manmade and administrative landscapes are updated daily. We collect this information in a variety of ways, for the NGD as well as to develop our OS MasterMap®, a continually updated database of 450 million geographic features. This data is relied upon by millions – including government, utilities and the private sector.

Data collection

We collect data in a number of ways including:


We’ve 250 field surveyors across Great Britain supporting the Continuous Revision Programme. They promptly survey the most significant changes to the ‘built environment’ including new buildings, roads, names and addresses.

They also capture and maintain information which underpins the land registration process in England, Wales and Scotland.

Field surveyors work with Ordnance Survey’s central Geospatial Data Management System (GDMS), which contains the most detailed mapping of Great Britain in a single data model. From this, OS MasterMap® is produced. It contains a suite of different layers, each providing a different aspect of mapping data for use in a Geographic Information system (GIS).

Aerial imagery

The Remote Sensing department captures change with aerial photography, sourced from our OS flying unit and external suppliers. Aircraft capture high definition imagery between March and November. The digital camera data is downloaded after flying for processing at one of 30 digital photogrammetric workstations.

The workstations display stereo-images overlaid with map data. For these, geographically adjacent aerial images are overlapped. Polarised glasses allow the two images to be viewed as a single image in 3D. By adjusting the level of overlap, we can accurately measure the height and position of features on the landscape.

External suppliers

OS works with a number of external suppliers who support data delivery and services. These include getting aerial photography, creating digital imagery and height datasets and maintaining and improving topographic data.

Data management

Once collected, data is used in a number of ways to create Ordnance Survey’s datasets:

Data enhancement

The Data Enhancement team uses a range of advanced GIS to add value to the topographic data.

Data Enhancement also manages ‘Change Intelligence’ – our knowledge of planned changes to the landscape which need to be captured. It identifies the ‘what, when and where’ of a particular feature such as a new road, building, building demolitions or the change of use of a building.

The team is also responsible for recording electoral and administrative boundaries with Great Britain.


OS cartographers put together the data to create derived products. They use ‘generalisation’ techniques which reduce real-world information down to readable and usable formats.

The product suite is also enhanced with data from other organisations – such as National Air Traffic Control (air charts); Defence Estates (low flying charts; defence training areas) and the Boundary Commission (parliamentary boundary information).


Our Quality Management team checks the produced work, assuring its processes, people and data as well as the products and services provided to customers. It involves ‘end to end’ audits and process reviews, assessment of production quality control measures and individual performance monitoring.

Data analysis

We can now analyse vast quantities of geospatial data to really understand location and improve business processes.

The power, value and application of geographical information can underpin important decision making. We have a number of case studies showing how our data saves companies millions of pounds a year in costs and efficiencies.

We can help you

Find out how we can help your organisation by contacting us at:
Telephone: +44 (0) 3456 05 05 05