-- Keeping up-to-date --

Ordnance Survey’s current workforce of around 1500 people includes more than 350 surveyors who constantly measure and record the changing British landscape from a network of offices stretching from Inverness to Truro. They use high-tech measuring equipment to gather information, including state-of-the-art theodolite 'total stations' with lasers to measure distances and hand-held pen computers on which the latest changes can be plotted. Details are recorded as fine as the shapes of individual buildings, the precise alignment of roads and pavements and the exact location of public telephone boxes.

Surveying staff also pinpoint precise locations at ground level by using Global Positioning System (GPS) receiving equipment to lock on to signals from a network of 24 orbiting satellites. Previously thousands of triangulation stations – including the familiar concrete ‘trig pillars’ on high ground – were the bedrock for positioning calculations, but this method has now been superseded.

Information gathered by ground staff is complemented by an intensive programme of aerial photography, particularly of rural areas, which can be viewed in 3D. The resulting high-definition images – which show detail as sharp as the pattern of road markings – can then be overlaid with existing map data to check where features have changed so that instant updates can be recorded.

-- Free Maps for 11 Year-Olds --

Ordnance Survey is offering a free Explorer map to every 11-year-old in Britain: to take advantage of the scheme teachers have to first register their order on our web site. Although distributed by schools, the maps will be owned by the children themselves.

Qualifying Primary 7 pupils at nearly 1,500 Scottish schools – alongside Year 7 pupils at 5,500 schools in England and Wales – will be able to use their maps to discover their local area with their families, while in the classroom they will be able to use them in geography, history, environmental studies, citizenship and other lessons.