Ordnance Survey





Ordnance Survey, an executive agency and non-ministerial government department of the Government of the United Kingdom, is the national mapping agency for Great Britain, producing maps of Great Britain (and to an extent, the Isle of Man). It does not produce maps of Northern Ireland. It is one of the world's largest producers of maps.

The name reflects its creation together with the original military purpose of the organisation (see ordnance and surveying) in the first instance in mapping Scotland in the immediate aftermath of the last Jacobite Rebellion, which included the last pitched battle on British soil at the Battle of Culloden. Moreover there was not only a recent history of conflict in the region, but the tendency for wars to break out in Britain had a precedent stretching back centuries. The government's fears, and with it the justification for the importance of military mapping among other things, were vindicated later during the Napoleonic Wars when there was a threat of invasion from France, and its logo includes the War Department's broad arrow heraldic mark. Ordnance Survey mapping is usually classified as 'large scale' (i.e. showing more detail) or 'small scale'. Large-scale mapping comprises maps at six inches to the mile or more (1:10,560, superseded by 1:10,000 in the 1950s); it was available in sheet-map form until the 1980s, since when it has become digital. Small-scale mapping comprises maps at fewer than six inches to the mile and includes the "leisure maps", such as the popular one inch to the mile and its metric successors, still available in traditional sheet-map form. Ordnance Survey of Great Britain maps are in copyright for 50 years after publication date. Some of the Copyright Libraries hold complete or near-complete collections of pre-digital O.S. mapping.

Origins
The roots of Ordnance Survey go back to 1747, when Lieutenant-Colonel David Watson proposed the compilation of a map of the Scottish Highlands to facilitate the subjugation of the clans following the Jacobite rising of 1745. In response, King George II commissioned a military survey of the Highlands, and Watson was placed in charge under the command of the Duke of Cumberland. Among his assistants were William Roy, Paul Sandby, and John Manson. The survey was produced at a scale of 1 inch to 1000 yards (1:36,000). The labours of Watson and Roy, in particular, resulted in The Duke of Cumberland's Map, now in the British Library.

Roy would go on to have an illustrious career in the Royal Engineers, and he was largely responsible for the British share of the work in determining the relative positions of the French and British royal observatories. This work was the starting point of the Principal Triangulation of Great Britain (1783–1853), and led to the creation of the Ordnance Survey itself. Roy's technical skills and leadership set the high standard for which Ordnance Survey became known. Work was begun in earnest in 1790 under Roy's supervision, when the Board of Ordnance (a predecessor of part of the modern Ministry of Defence) began a national military survey starting with the south coast of England.

By 1791, the Board received the newer Ramsden theodolite (an improved successor to the one that Roy had used in 1784), and work began on mapping southern Great Britain using 5-mile baseline on Hounslow Heath that Roy himself had previously measured and that crosses the present Heathrow Airport. A set of postage stamps, featuring maps of the Kentish village of Hamstreet, was issued in 1991 to mark the bicentenary.

In 1801, the first one-inch-to-the-mile (1:63,360 scale) map was published, detailing the county of Kent, with Essex following shortly after. The Kent map was published privately and stopped at the county border while the Essex maps were published by Ordnance Survey and ignore the county border, setting the trend for future Ordnance Survey maps.

During the next twenty years, roughly a third of England and Wales was mapped at the same scale (see Principal Triangulation of Great Britain) under the direction of William Mudge, as other military matters took precedence. It took until 1823 to re-establish a relationship with the French survey made by Roy in 1787. By 1810, one inch to the mile maps of most of the south of England were completed, but were withdrawn from sale between 1811 and 1816 because of security fears. It was gruelling work: Major Thomas Colby, later the longest serving Director General of Ordnance Survey, walked 586 mi in 22 days on a reconnaissance in 1819. In 1824, Colby and most of his staff moved to Ireland to work on a six-inches-to-the-mile (1:10,560) valuation survey. The survey of Ireland, county by county, was completed in 1846. The suspicions and tensions it caused in rural Ireland are the subject of Brian Friel's play Translations.

Colby was not only involved in the design of specialist measuring equipment. He also established a systematic collection of place names, and reorganised the map-making process to produce clear, accurate plans. Place names were recorded in "Name Books", a system first used in Ireland. The instructions for their use were: "The persons employed on the survey are to endeavour to obtain the correct orthography of the names of places by diligently consulting the best authorities within their reach. The name of each place is to be inserted as it is commonly spelt, in the first column of the name book and the various modes of spelling it used in books, writings &c. are to be inserted in the second column, with the authority placed in the third column opposite to each''." Whilst these procedures generally produced excellent results, mistakes were made: for instance, the Pilgrims Way in the North Downs labeled the wrong route, but the name stuck. Similarly, the spelling of Scafell and Scafell Pike copied an error on an earlier map, and was retained as this was the name of a corner of one of the Principal Triangles, despite "Scawfell" being the almost universal form at the time.

Colby believed in leading from the front, travelling with his men, helping to build camps and, as each survey session drew to a close, arranging mountain-top parties with enormous plum puddings.

The British Geological Survey was founded in 1835 as the Ordnance Geological Survey, under Henry De la Beche and remained a branch of the Ordnance Survey until 1965. At the same time the uneven quality of the English and Scottish maps was being improved by engravers under Benjamin Baker. By the time Colby retired in 1846, the production of six-inch maps of Ireland was complete. This had led to a demand for similar treatment in England and work was proceeding on extending the six-inch map to northern England, but only a three-inch scale for most of Scotland.

When Colby retired he recommended William Yolland as his successor, but he was considered too young and a less experienced Lewis Hall was appointed instead. When after a fire in the Tower of London, the headquarters of the survey was moved to Southampton, Yolland was put in charge, but Hall sent him off to Ireland so that he was again passed over when Hall left in 1854 in favour of Major Henry James. Hall was enthusiastic about extending the survey of the north of England to a scale of 1:2,500. In 1855, the Board of Ordnance was abolished and the Ordnance Survey was placed under the War Office together with the Topographical Survey and the Depot of Military Knowledge. Eventually in 1870 it was transferred to the Office of Works.

The primary triangulation of the United Kingdom of Roy, Mudge and Yolland was completed by 1841, but was greatly improved by Alexander Ross Clarke who completed a new survey based on Airy's spheroid in 1858, completing the Principal Triangulation. The following year he completed an initial levelling of the country.

Publication of the one inch to the mile series for Great Britain was completed in 1891.

The Great Britain 'County Series'
After the first Ireland maps came out in the mid-1830s, the Tithe Commutation Act 1836 led to calls for a similar six-inch to the mile survey in England and Wales. Official procrastination followed, but the development of the railways added to pressure that resulted in the Ordnance Survey Act 1841. This granted a right to enter property for the purpose of the survey. Following a fire at its headquarters at the Tower of London in 1841 the Ordnance Survey relocated to a site in Southampton and was in disarray for several years, with arguments about which scales to use. Major-General Sir Henry James was by then Director General, and he saw how photography could be used to make maps of various scales cheaply and easily. He developed and exploited photozincography, not only to reduce the costs of map production but also to publish facsimiles of nationally important manuscripts. Between 1861 and 1864, a facsimile of the Domesday Book was issued, county by county, and in 1870 a facsimile of the Gough Map.

From the 1840s the Ordnance Survey concentrated on the Great Britain 'County Series', modelled on the earlier Ireland survey. A start was made on mapping the whole country, county by county, at six inches to the mile (1:10,560). From 1854, to meet requirements for greater detail, including land-parcel numbers in rural areas and accompanying information, cultivated and inhabited areas were mapped at 1:2500 (25.344 inches to the mile), at first parish by parish, with blank space beyond the parish boundary, and later continuously. Early copies of the 1:2500s were available hand-coloured. Up to 1879, the 1:2500s were accompanied by Books of Reference or "area books" that gave acreages and land-use information for land-parcel numbers. After 1879, land-use information was dropped from these area books; after the mid-1880s, the books themselves were dropped and acreages were printed instead on the maps. After 1854, the six-inch maps and their revisions were based on the "twenty-five inch" maps and theirs. The six-inch sheets covered an area of six by four miles on the ground; the "twenty-five inch" sheets an area of one by one and a half. One square inch on the "twenty-five inch" maps was roughly equal to an acre on the ground. In later editions the six-inch sheets were published in "quarters" (NW,NE,SW,SE), each covering an area of three by two miles on the ground. The first edition of the two scales was completed by the 1890s. A second edition (or "first revision") was begun in 1891 and completed just before the First World War. From 1907 till the early 1940s, a third edition (or "second revision") was begun but never completed: only areas with significant changes on the ground were revised, many two or three times.

Meanwhile funding had been agreed in the 1850s for a more detailed survey of towns and cities. From 1850–53, twenty-nine towns were mapped at 1:528 (10 feet to the mile). From 1855 1:500 (10.56 feet to the mile) became the preferred scale. London and some seventy other towns (mainly in the north) were already being mapped at 1:1056 (5 feet to the mile). Just under 400 towns with a population of over 4000 were surveyed at one of these three scales, most at 1:500. Publication of the town plans was completed by 1895. The London first edition was completed and published in 326 sheets in the 1860s–70s; a second edition of 759 sheets was completed and brought out in the early 1890s; further revisions (incomplete coverage of London) followed between 1906 and 1937. Very few other towns and cities saw a second edition of the town plans.

From 1911 onwards (mainly 1911–1913), the Ordnance Survey photo-enlarged to 1:1250 (50.688 inches to the mile) many 1:2500 sheets covering built-up areas, for Land Valuation / Inland Revenue purposes. About a quarter of these 1:1250s were marked "Partially revised 1912/13". In areas where there were no further 1:2500s, these partially revised "fifty inch" sheets represent the last large-scale revision (larger than six-inch) of the County Series. The County Series mapping was superseded by the Ordnance Survey National Grid 1:1250s, 1:2500s and 1:10,560s after the Second World War.

From the late 19th century to the early 1940s, for War Office purposes, the O.S. produced many "restricted" versions of the County Series maps and other War Department sheets, in a variety of large scales, that included details of military significance, such as dockyards, naval installations, fortifications, and military camps. These areas were left blank or incomplete on standard maps – though for a brief period in the early 1930s, during the Disarmament talks, some of the blanks were filled in. The War Department 1:2500s, unlike the standard issue, were contoured. The de-classified sheets have now been deposited in some of the Copyright Libraries, helping to complete the map-picture of pre-Second World War Britain.

20th century




During the First World War, Ordnance Survey was involved in preparing maps of France and Belgium for its own use, and many more maps were created during World War II, including: After the war, Colonel Charles Close, then Director General, developed a marketing strategy using covers designed by Ellis Martin to increase sales in the leisure market. In 1920 O. G. S. Crawford was appointed Archaeology Officer and played a prominent role in developing the use of aerial photography to deepen understanding of archaeology.
 * 1:40000 scale map of Antwerp, Belgium
 * 1:100000 scale map of Brussels, Belgium
 * 1:5000000 scale map of South Africa
 * 1:250000 scale map of Italy
 * 1:50000 scale map of Northeast France
 * 1:30000 scale map of the Netherlands with manuscript outline of German Army occupation districts.

In 1935, the Davidson Committee was established to review Ordnance Survey's future. The new Director General, Major-General Malcolm MacLeod, started the retriangulation of Great Britain, an immense task involving erecting concrete triangulation pillars (trig points) on prominent hilltops (some being difficult to reach) throughout Great Britain. These were intended to be infallibly constant positions for the theodolites during the many angle measurements, which were each repeated no fewer than 32 times.

The Davidson Committee's final report set Ordnance Survey on course for the twentieth century. The national grid reference system was launched, with the metre as its unit of measurement. A 1:25000 scale series was introduced, experimentally at first. The one-inch maps remained for almost forty years until the 1970s before being superseded by the 1:50000 scale series, as proposed by William Roy more than two centuries earlier.

Ordnance Survey had outgrown its site in the centre of Southampton (made worse by the bomb damage of the Second World War). The bombing during the Blitz devastated Southampton in November 1940 and destroyed most of Ordnance Survey's city centre offices. Staff were dispersed to other buildings, and to temporary accommodation at Chessington and Esher, Surrey, where they produced 1:25000 scale maps of France, Italy, Germany and most of the rest of Europe in preparation for the invasion of Europe. Ordnance Survey largely remained at its Southampton city centre HQ and temporary buildings nearby in the Southampton suburb of Maybush until 1969, when a new purpose-built headquarters was opened in Maybush adjacent to the wartime temporary buildings there. Some of the remaining buildings of the original Southampton city-centre site are now used as part of the court complex.

The then-new head office building was designed by the Ministry of Public Buildings and Works (MPBW) for 4000 staff, including many new recruits that were taken on in the late 1960s and early 70s as draughtsmen and surveyors. The buildings originally contained factory floor space for photographic processes such as Heliozincography and printing of maps, as well as large buildings for storing flat maps. Above the industrial areas are extensive office areas. The complex is notable for its concrete mural by sculptor Keith McCarter and the concrete elliptical paraboloid shell roof over the staff restaurant building.

In 1995, Ordnance Survey digitised the last of about 230,000 maps, making the United Kingdom the first country in the world to complete a programme of large-scale electronic mapping. In 1999 Ordnance Survey was designated a Trading Fund, required to cover its costs by charging for its products and remit a proportion of its profits to the Treasury. Officially, it is now a civilian organisation with executive agency status.

By the late 1990s, the need for vast areas for storing maps and for making printing plates by hand had been made obsolete by technological developments. Although there was a small computer section at Ordnance Survey in the 1960s, the digitising programme had replaced the need for printing large-scale maps while computer-to-plate technology in the form of a single CTP machine had also made obsolete the photographic platemaking areas. Part of the latter was converted into a new conference centre in 2000, which was used for both internal events and made available for external organisations to hire.

In summer 2010, the announcement was made that printing and warehouse operations were to be outsourced, ending over 200 years of in-house printing. As already stated, large-scale maps had not been printed at Ordnance Survey since the common availability of geographical information systems (GIS), but until late 2010, the OS Explorer Map and OS Landranger Map leisure products were printed in Maybush.

In April 2009 construction began on a new head office located at Adanac Park on the outskirts of Southampton.

As of 10 February 2011, virtually all staff had relocated to the new building 'Explorer House' and the old site was sold off and redeveloped. Prince Philip, Duke of Edinburgh officially opened the new headquarters building on 4 October 2011.

GB map range
Ordnance Survey produces a large variety of paper maps and digital mapping products.

Business mapping
Ordnance Survey produces a wide variety of different products aimed at business users, such as utility companies and local authorities. The data is supplied by Ordnance Survey on optical media or increasingly, via the Internet. Products can be downloaded via FTP or accessed 'on demand' via a web browser. Organisations using Ordnance Survey data have to purchase a licence to do so. Some of the main products are:
 * OS MasterMap – Ordnance Survey's most detailed mapping showing individual buildings and other features in a vector format. Every real-world object is assigned a unique reference number (TOID) that allows customers to add this reference to their own databases. OS MasterMap consists of several 'layers', the main one being the Topography Layer but also available are aerial imagery, transport links and postcodes.
 * OS VectorMap Local – a recently launched customisable vector product at 1:10 000 scale.
 * OS Landplan – a raster map at 1:10 000 scale
 * Meridian 2 and Strategi – mid-scale vector mapping.
 * ADDRESS-POINT and Code-Point – Datasets with address information, allowing postcode searches of maps and so on. This is a joint venture with Royal Mail.
 * Boundary-Line – Mapping showing administrative boundaries, such as counties, parishes and electoral wards.
 * 1:10 000, 1:25 000, 1:50 000 and 1:250,000 Scale Raster – raster versions of the leisure maps at those scales.
 * OS Street View – highly simplified mapping that focuses on showing streets and their names at the expense of other features.
 * Land-Form PROFILE, PROFILE Plus and Panorama – these are digital terrain models.

Leisure maps
OS's range of leisure maps are published in a variety of scales:
 * Tour (c.1:100,000 scale except Scotland) – One-sheet maps covering a generally county-sized area, showing major and most minor roads and containing tourist information and selected footpaths. Tour maps are generally produced from enlargements of 1:250,000 mapping. Several larger scale town maps are provided on each sheet for major settlement centres. The Tour maps have sky-blue covers and there are eight sheets in the series.
 * OS Landranger map (1:50,000 scale) – The "general purpose" map. They have pink covers; 204 sheets cover the whole of Great Britain and the Isle of Man. The map shows all footpaths and the format is similar to that of Explorer, albeit with less detail.
 * OS Landranger Active map (1:50,000 scale) – select OS Landranger maps are available in a plastic-laminated waterproof version, similar to the OS Explorer Active range., 25 of the 204 Landranger maps were available as OS Landranger Active maps.
 * OS Explorer map and Outdoor Leisure (1:25,000 scale) – Specifically designed for walkers and cyclists. They have orange covers, and the two series together contain 403 sheets covering the whole of Great Britain (the Isle of Man is excluded from this series). These are the most detailed leisure maps that Ordnance Survey publish and cover all types of footpaths and most details of the countryside for easy navigation. The Outdoor Leisure series complement the OS Explorer Map, showing areas of greater interest in England and Wales (e.g. Lake District, Black Mountains) with an enlarged area coverage. It appears identical to the Explorer, except the numbering and a little yellow mark on the corner (relic of the old OL series). The OS Explorer maps, together with Outdoor Leisure, superseded the previous Pathfinder maps (green covers) which were numerous in their coverage of the country.
 * OS Explorer Active map (1:25,000 scale) – the OS Explorer and Outdoor Leisure maps are also available in a plastic-laminated waterproof version.

Until 2010, OS also produced the following: These, along with fifteen Tour maps, were discontinued during January 2010 as part of a drive for cost-efficiency, Ordnance Survey believing these products could no longer compete with similar maps produced by other companies and satellite navigation devices.
 * Route (1:625,000 scale) – A double-sided map designed for long-distance road users, covering the whole of Great Britain.
 * Road (1:250,000 scale) – A series of eight sheets covering Great Britain, designed for road users.

Custom products
Ordnance Survey also offers a print-on-demand service called 'OS Custom Made'. This is printed to order from digital raster data, allowing the customer to choose exactly which area the map should cover. There is choice of two scales: 1:50,000 (area covered 40 km x 40 km) or 1:25,000 (area covered 20 km x 20 km).

Ordnance Survey also produces more detailed custom mapping at 1:10,000 (Landplan) and 1:1,250 or 1:500 (Siteplan), which is available from some of the more specialist outlets. Again, this is produced to order from Ordnance Survey large-scale digital data, and custom scales can also be produced by enlargement or reduction of existing scales.

Educational mapping
Ordnance Survey produces maps for educational use, which are faithful reproductions of old Ordnance Survey maps dating from the early 1970s to the early 1990s (estimated). These maps are widely seen in British schools and schools in former British colonies (including the Commonwealth), either as stand-alone geographic aids or sold as part of geography workbooks and/or textbooks.

From the early 2000s, Ordnance Survey offered a free OS Explorer Map to every 11-year-old in UK primary education in an attempt to increase school children's awareness of maps. By the end of 2010 when the scheme closed, over 6 million maps had been given away. In place of the Free maps for 11-year-olds scheme, all schools that were eligible to receive free maps will have free access to the Digimap for Schools service provided by EDINA. This service is available to all schools, though those who are not eligible for free maps have to pay "a modest annual fee".

With the trend away from paper products towards geographical information systems (GIS), Ordnance Survey has been looking into ways of ensuring schoolchildren are made aware of the benefits of GIS and has launched an interactive website aimed at children called 'MapZone' that features map-related games and learning resources. Ordnance Survey publishes a quarterly journal aimed at geography teachers called 'Mapping News'.

Derivative and licensed products
One series of historic maps (published by Cassini Publishing Ltd) is a reprint of the Ordnance Survey first series from the mid 19th century, but re-scaled to 1:50,000, re-projected to the OS Landranger map projection, and given 1 km gridlines. This means that features from over 150 years ago fit almost exactly over their modern equivalents, and modern grid references can be given to old features.

The digitisation of the data has allowed Ordnance Survey to experiment with selling maps electronically. Several companies are now licensed to produce the popular scales (1:50,000 and 1:25,000) of map on CD/DVD or to make them available online for download. The buyer typically has the right to view the maps on a PC, a laptop and a pocket PC/smartphone, and to print off any number of copies. The accompanying software is GPS-aware, and the maps are ready-calibrated. Thus, the user can quickly transfer a desired area from their PC to their laptop or smartphone, and go for a drive or walk with their position continually pinpointed on the screen. The price for an individual map is more expensive than the equivalent paper version, but the price per square km falls rapidly with the size of coverage bought.

Cartography


The original maps were made by triangulation. For the second survey, in 1934, this process was used again, and resulted in the building of many triangulation pillars (trig points): short (approx. 4 feet/1.2 m high), usually square, concrete or stone pillars at prominent locations such as hill tops. Their precise locations were determined by triangulation, and the details in between were then filled in with less precise methods.

Modern Ordnance Survey maps are largely based on aerial photographs, but large numbers of the pillars remain, many of them adopted by private land owners. Ordnance Survey still has a team of surveyors across Great Britain who visit in person and survey areas that cannot be surveyed using photogrammetric methods (such as land obscured by vegetation) and there is an aim of ensuring that any major feature (such as a new motorway or large housing development) is surveyed within six months of its construction. While original survey methods were largely manual, the current surveying task is simplified by the use of GPS technology, allowing the most precise surveying standards yet. Ordnance Survey is responsible for a UK-wide network of GPS stations, known as OS Net. These are used for surveying but other organisations can purchase the right to utilise the network for their own uses.

Ordnance Survey still maintains a set of master geodetic reference points to tie the Ordnance Survey geographic datums to modern measurement systems including GPS. Ordnance Survey maps of Great Britain do not use latitude and longitude to indicate position but a special grid. The grid is technically known as OSGB36 (Ordnance Survey Great Britain 1936), and was introduced after the retriangulation of 1936–53.

OS MasterMap
Ordnance Survey's flagship digital product, launched in November 2001, is OS MasterMap. This is a database that records every fixed feature of Great Britain larger than a few metres in one continuous digital map. Every feature is given a unique TOID (TOpographical IDentifier), a simple identifier that includes no semantic information. Typically each TOID is associated with a polygon that represents the area on the ground that the feature covers, in National Grid coordinates.

OS MasterMap layers
OS MasterMap is offered in themed 'layers', each linked to a number of TOIDs. As of September 2010, the layers are:
 * OS MasterMap Topography Layer – the primary layer of OS MasterMap, consisting of vector data comprising large-scale representation of features in the real world, such as buildings and areas of vegetation. The features captured and the way they are depicted is listed in a specification available on the Ordnance Survey website.
 * OS MasterMap Integrated Transport Network Layer – this is a link-and-node network of transport features, such as roads and railways. This data is at the heart of many satnav systems. In an attempt to reduce the number of HGVs using unsuitable roads, a data capture programme of 'Road Routing Information' was recently undertaken and this aims to add information such as bridge height restrictions and one-way streets to the product.
 * OS MasterMap Imagery Layer – as the name suggests, this product is ortho-rectified raster format aerial photography.
 * OS MasterMap Address Layer and Address Layer 2 – this shows every address in the UK as an overlay to the other layers. Address Layer 2 adds additional information, such as addresses with multiple occupants (blocks of flats, student houses etc.) and objects with no postal address, such as fields and electricity substations.

Pricing of licenses to OS MasterMap data depends on the total area requested, the layers licensed, the number of TOIDs in the layers, and the period in years of the data usage.

OS MasterMap can be used to generate maps for a vast array of purposes, and maps can be printed from OS MasterMap data with detail equivalent to a traditional 1:1250 scale paper map.

Ordnance Survey states that OS MasterMap data is never more than six months out of date, thanks to continuous review. The scale and detail of this mapping project is unique. By 2009, around 440 million TOIDs had been assigned, and the database stood at 600 gigabytes in size; currently (March 2011) OS claims 450 million TOIDs. As of 2005, OS MasterMap was at version 6; 2010's version 8 includes provision for Urban Paths (an extension of ITN) and pre-build address layer. All these versions have a similar GML 2 schema.

Ordnance Survey is encouraging users of its old OS Land-Line data to migrate to OS MasterMap and in June 2007 announced a notice of withdrawal for this product as of 30 September 2008. Land-Line was a first-generation digital mapping product consisting of 'tiles' of map data. OS MasterMap is described as 'seamless', with no tiles, allowing customers to be more specific about their areas of interest.

Geographical information science research
For several decades, Ordnance Survey has had a research department that is active in several areas of geographical information science, including:
 * Spatial cognition
 * Map generalisation
 * Spatial data modelling
 * Remote sensing and analysis of remotely sensed data
 * Semantics and ontologies

Ordnance Survey actively supports the academic research community through its external research and university liaison team. The research department actively supports MSc and PhD students as well as engaging in collaborative research. Most Ordnance Survey products are available to UK universities that have signed up to the Digimap agreement and data is also made available for research purposes that advances Ordnance Survey's own research agenda.

More information can be found at Ordnance Survey Research.

Access to data and criticisms
Ordnance Survey has been subject to criticisms. Most criticism centres on the point that Ordnance Survey possesses a virtual government monopoly on geographic data in the UK, while, although a government agency, since 1999 it has been required to act as a Trading Fund or commercial entity. This means that it is supposed to be totally self-funding from the commercial sale of its data and derived products – whilst at the same time it is supposed to be the public supplier of geographical information. In 1985 the "Committee of Enquiry into the Handling of Geographic Information" was set up to "advise the Secretary of State for the Environment within two years on the future handling of geographic information in the UK, taking account of modern developments in information technology and market needs". The Committee's final report was published under the name of its chairman, Roger Chorley, in 1987. The report stressed the importance of widely available geographic information to the UK and recommended a loosening of government policies on distribution and cost recovery.

Since August 2007, Ordnance Survey has contracted the political lobbying company Mandate Communications to help campaign against the free data movement and discover which politicians and advisers continue to support their current policies.

OS OpenData
In response to the feedback from the consultation, the government announced that a package of Ordnance Survey data sets would be released for free use and re-use. On 1 April 2010 Ordnance Survey released the brand OS OpenData, under an attribution-only license compatible with CC-by. Various groups and individuals had campaigned for this release of data, but some were disappointed when some of the profitable datasets were not included – withheld for the counter-argument that if licensees do not pay for OS data collection then the government would have to be willing to foot a £30m p.a. bill, to obtain the future economic benefit of sharing the highly detailed mapping produced by the UK's national agency.

In mid-2013, Ordnance Survey described an "enhanced" Linked data service providing a SPARQL 1.1-compliant endpoint and bulk download options for linked data content.

Historical material
Ordnance Survey historical works are generally available, as the agency is covered by Crown Copyright: works more than fifty years old, including historic surveys of Britain and Ireland and much of the New Popular Edition, are in the public domain. However, finding suitable originals remains an issue as Ordnance Survey does not provide historical mapping on 'free' terms, instead marketing commercially 'enhanced' reproductions in partnership with Landmark. This can be contrasted with, for example, the approach in the Republic of Ireland in more recent times, where Ordnance Survey Ireland claims regular copyright over its mapping (and over digital copies of the public domain historical mapping).

Visual identity
The graphic identity, including the OS logotype, was developed in 1997 by the British design consultancy, Lloyd Northover, founded by John Lloyd and Jim Northover.