Ordnance Survey

Ordnance Survey is a national mapping agency in the United Kingdom which covers the island of Great Britain. 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 remain 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 : mapping Scotland in the wake of the Jacobite rebellion in 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" or "small-scale". The Survey's large-scale mapping comprises 1:2,500 maps for urban areas and 1:10,000 more generally. 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 available in traditional sheet form.