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Ordnance Survey (OS) is a national mapping agency in the United Kingdom which covers the island of Great Britain.[1] It is one of the world’s largest producers of maps. Since 1 April 2015 it has operated as Ordnance Survey Ltd, a government-owned company, 100% in public ownership. The Ordnance Survey Board remains accountable to the Secretary of State for Business, Energy and Industrial Strategy. It is also a member of the Public Data Group.
The agency’s name indicates its original military purpose (see ordnance and surveying), which was to map Scotland in the wake of the Jacobite rising of 1745. There was also a more general and nationwide need in light of the potential threat of invasion during the Napoleonic Wars.
Ordnance Survey mapping is usually classified as either “large-scale” (in other words, more detailed) or “small-scale”. The Survey’s large-scale mapping comprises 1:2,500 maps for urban areas and 1:10,000 more generally. (The latter superseded the 1:10,560 “six inches to the mile” scale in the 1950s.) These large scale maps are typically used in professional land-use contexts and were available as sheets until the 1980s, when they were digitised. Small-scale mapping for leisure use includes the 1:25,000 “Explorer” series, the 1:50,000 “Landranger” series and the 1:250,000 road maps. These are still
