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{{short description|National mapping agency for Great Britain}}
{{About||the former agency of Ireland|Ordnance Survey Ireland|the former agency of Northern Ireland|Ordnance Survey of Northern Ireland|an international agency|Ordnance Survey International}}
{{Use British English|date=October 2013}}
{{Use dmy dates|date=May 2024}}
{{Infobox government agency
| agency_name = Ordnance Survey
| type =
| nativename = {{langx|cy|Arolwg Ordnans}}
| nativename_a =
| nativename_r =
| logo = Ordnance Survey 2015 Logo.svg
| logo_width = 240px
| logo_caption =
| seal =
| seal_width =
| seal_caption =
| picture =
| picture_width =
| picture_caption =
| formed = {{start date and age|df=yes|1791||}}
| preceding1 =
| dissolved =
| superseding =
| jurisdiction = Great Britain<ref group="Notes" name="RegionServed">The Ordnance Survey deals only with maps of Great Britain, and, to an extent, the [[Isle of Man]], but not Northern Ireland, which has its own, separate government agency, the [[Ordnance Survey of Northern Ireland]].</ref>
| headquarters = [[Southampton]], England, UK
| region_code = GB
| coordinates = {{coord|50.9378|-1.4713|region:GB-STH_type:landmark|display=inline,title}} OS grid SU 373 155
| employees = 1,244
| budget =
| minister1_name = [[Peter Kyle]]
| minister1_pfo = [[Secretary of State for Science, Innovation and Technology]]
| chief1_name = Nick Bolton
| chief1_position = [[Chief executive officer|CEO]]
| agency_type =
| parent_agency = [[Department for Science, Innovation and Technology]]
| child1_agency =
| keydocument1 =
| website = {{nowrap|{{official URL}}}}
| footnotes =
| map =
| map_width =
| map_caption =
}}
[[File:Ordnance Survey 1-250000 - TF.jpg|thumb|[[Ordnance Survey National Grid|Grid square]] TF from the [[Ordnance Survey National Grid]], shown at a [[Scale (map)|scale]] of 1:250,000. The map shows [[the Wash]] and the [[North Sea]], as well as places within the counties of [[Lincolnshire]], Cambridgeshire and [[Norfolk]].]]
[[File:Grays Thurrockmap 1946.jpg|thumb|Part of an Ordnance Survey map, at the scale of one inch to the mile, from a New Popular Edition map published in 1946]]
[[File:Mansewood1747-1755.jpg|thumb|[[Pollokshaws]] on [[William Roy|Roy]]'s Military Survey of Scotland (1747–1755)<ref name="Roy and OS 1 inch">{{cite web | title=Side by side georeferenced maps viewer – Roy Lowlands 1752–55, One inch 7th series 1956–1961 | website=National Library of Scotland | date=16 March 2022 | url=https://maps.nls.uk/geo/explore/side-by-side/#zoom=14&lat=55.82410&lon=-4.28800&layers=4&right=11 | access-date=7 May 2022 | archive-date=7 May 2022 | archive-url=https://web.archive.org/web/20220507180916/https://maps.nls.uk/geo/explore/side-by-side/#zoom=14&lat=55.82410&lon=-4.28800&layers=4&right=11 | url-status=live }}</ref>]]
<!--
References have been added retrospectively. The majority of the information on this page can be found on the Ordnance Survey's official website [http://www.ordnancesurvey.co.uk/oswebsite/about-us/our-history/index.html From one revolution to another], as per References list.
--->
The '''Ordnance Survey''' ('''OS''') is the [[national mapping agency]] for Great Britain.<ref>{{cite web |url=https://www.gov.uk/government/organisations/ordnance-survey |title=Ordnance Survey |publisher=Government of the United Kingdom |access-date=21 February 2017 |archive-date=25 February 2017 |archive-url=https://web.archive.org/web/20170225131117/https://www.gov.uk/government/organisations/ordnance-survey |url-status=live }}</ref> The agency's name indicates its original military purpose (see [[Artillery|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]]. Since 1 April 2015, the Ordnance Survey has operated as Ordnance Survey Ltd, a [[state-owned enterprise|government-owned company]], 100% in public ownership. The Ordnance Survey Board remains accountable to the [[Secretary of State for Science, Innovation and Technology]]. It was also a member of the [[Public Data Group]].
Paper maps represent only 5% of the company's annual revenue. It produces digital map data, online route planning and sharing services and mobile apps, plus many other ___location-based products for business, government and consumers. Ordnance Survey mapping is usually classified as either "[[Scale (map)|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 [[inch]]es to the [[mile]]" scale in the 1950s.) These large scale maps are typically used in professional [[Land use|land-use]] contexts and were available as sheets until the 1980s, when they were [[Digitizing|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.
Ordnance Survey maps remain in [[copyright]] for 50 years after their <!-- [first?] --> publication. Some of the [[Legal deposit#United Kingdom|copyright libraries]] hold complete or near-complete collections of pre-digital OS mapping.
==History==
===Origins===
{{stack|
[[File:Ordnance Survey Drawings - St. Columb Major, Cornwall (OSD 7).jpg|thumb|The [[Ordnance Survey Drawings|original draftsman's drawings]] for the area around [[St Columb Major]] in [[Cornwall]], made in 1810.]]
[[File:St George's Town and St George's Garrison , Bermuda OS Map Lieut AJ Savage 1901.jpg|thumb|Detail from 1901 Ordnance Survey map of the [[Imperial fortress]] [[British Overseas Territory|colony]] of [[Bermuda]] (showing [[St. George's, Bermuda|St. George's Town]] and [[St. George's Garrison, Bermuda|St. George's Garrison]]), compiled from surveys carried out between 1897 and 1899 by Lieutenant Arthur Johnson Savage, [[Royal Engineers]].]]
}}
The origins of the Ordnance Survey lie in the aftermath of the [[Jacobite rising of 1745]]. [[Prince William, Duke of Cumberland]] realised that the British Army did not have a good map of the [[Scottish Highlands]] to locate [[Jacobitism|Jacobite]] dissenters such as [[Simon Fraser, 11th Lord Lovat]] so that they could be put on trial.{{sfn|Hewitt|2010|p=xix}} In 1747, Lieutenant-Colonel [[David Watson (British Army officer)|David Watson]] proposed the compilation of a map of the Highlands to help in pacifying the region.{{Sfn|Porter|1889|pp=167–168}} In response, [[George II of Great Britain|King George II]] charged Watson with making a military survey of the Highlands under the command of the Duke of Cumberland. Among Watson's assistants were [[William Roy]], [[Paul Sandby]] and John Manson. The survey was produced at a scale of 1 inch to 1,000 yards (1:36,000){{sfn|Hindle|1998|pp=114–115}} and included "[[the Duke of Cumberland's Map]]" (primarily by Watson and Roy), now held in the [[British Library]].<ref>{{cite web |title=Roy Military Survey of Scotland, 1747–1755 | website=National Library of Scotland |url=https://maps.nls.uk/roy/originals.html}}</ref>
Roy later had an illustrious career in the [[Royal Engineers]] (RE), rising to the rank of General, 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 the 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 (United Kingdom)|Ministry of Defence]]) began a national military survey starting with the south coast of England. Roy's birthplace near [[Carluke]] in [[South Lanarkshire]] is today marked by a memorial in the form of a large OS [[trig point]].<ref>OSGR NS 826497</ref>
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 a {{convert|5|mi|abbr=on|0}} baseline on [[Hounslow Heath]] that Roy himself had previously measured; it crosses the present [[Heathrow Airport]]. In 1991, [[Royal Mail]] marked the bicentenary by issuing a set of postage stamps featuring maps of the Kentish village of [[Hamstreet]].<ref>{{cite web |title=[Maps of Ham Street] / reproduced from a stamp designed by Howard Brown and issued by the Royal Mail on 17 September 1991 |website=National Library of Australia |url=https://catalogue.nla.gov.au/catalog/6855787}}</ref>
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 afterwards. The Kent map was published privately and stopped at the county border, while the Essex maps were published by the Ordnance Survey and ignored the county border, setting the trend for future Ordnance Survey maps.{{sfn|Hindle|1998|p=117}}
During the next 20 years, about 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 the 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 they were withdrawn from sale between 1811 and 1816 because of security fears.{{sfn|Seymour|1980|p=71}} By 1840, the one-inch survey had covered all of Wales and all but the six northernmost counties of England.<ref>{{cite book |year=1947 |title=A Description of Ordnance Survey Large Scale Plans |place=Chessington |publisher=The Director General at the Ordnance Survey Office |page=2}}</ref>
Surveying was hard work. For instance, Major [[Thomas Frederick Colby|Thomas Colby]], the longest-serving Director General of the Ordnance Survey, walked {{convert|586|mi|abbr=on}} 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.{{sfn|Hindle|1998|p=114}} The suspicions and tensions it caused in rural Ireland are the subject of [[Brian Friel]]'s play ''[[Translations (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",{{sfn|Owen|Pilbeam|1992|p=30, 75 }}<ref name="nls.uk" /> a system first used in Ireland. The instructions for their use were:
{{blockquote|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]] labelled the wrong route, but the name stuck. Similarly, the spelling of [[Scafell]] and [[Scafell Pike]] copied an error on an earlier map,<ref>Facsimile reprint, ''Thomas Donald Historic Map of Cumberland 1774'', {{ISBN|9781873124369}}</ref> 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.<ref>{{cite web |title=Dorothy Wordsworth's ascent of Scafell Pike, 1818 |url= http://www.pastpresented.ukart.com/eskdale/wordsworth1.htm |website=Past presented}}</ref><ref>{{cite book |title=A Complete Guide to the English Lakes |last=Martineau |first=Harriet|url=https://archive.org/stream/completeguidetoe1855mart#page/n7/mode/2up |date=1855 |___location=Windermere |publisher=John Garnett |via=Internet Archive}}</ref><ref>{{cite book|last1=Holland|first1=CF|title=Climbs on the Scawfell Group – A Climbers' Guide. |date=1924 |publisher=Fell & Rock Climbing Club |edition=1st}}</ref> 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 pudding]]s.<ref name="ordnancesurvey.co.uk" />
[[File:Southampton-OSOld.jpg|thumb|The [[Ordnance Survey buildings, Southampton|former headquarters of the Ordnance Survey]] in London Road, [[Southampton]] (2005)]]
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.<ref>{{cite book |title=Reports from Committees |date=1851 |volume=4 |chapter=Ordnance Survey (Scotland) |page=[https://books.google.com/books?id=vpNMAAAAcAAJ&pg=RA4-PA197 197] |publisher = Parliament of the United Kingdom}}</ref>
{{Infobox UK legislation
| short_title = {{visible anchor|Survey Act 1870}}
| type = Act
| parliament = Parliament of the United Kingdom
| long_title = An Act to amend the Law relating to the Surveys of Great Britain, Ireland, and the Isle of Man.
| year = 1870
| citation = [[33 & 34 Vict.]] c. 13
| introduced_commons =
| introduced_lords =
| territorial_extent =
| royal_assent = 12 May 1870
| commencement =
| expiry_date =
| repeal_date =
| amends = [[Statute Law Revision Act 1883]]
| replaces =
| amendments =
| repealing_legislation =
| related_legislation =
| status =
| legislation_history =
| theyworkforyou =
| millbankhansard =
| original_text =
| revised_text =
| use_new_UK-LEG =
| UK-LEG_title =
| collapsed = yes
}}
When Colby retired, he recommended [[William Yolland]] as his successor, but he was considered too young and the less experienced Lewis Alexander Hall was appointed.{{sfn|Owen|Pilbeam|1992|p=44–45}} After a fire in the [[Tower of London]], the headquarters of the survey was moved to [[Ordnance Survey buildings, Southampton|Southampton]] taking over buildings previously occupied by a military orphanage (the [[Royal Military Asylum]]) in 1841,<ref>{{cite web |title=ROYAL MILITARY ASYLUM. (Hansard, 4 May 1854) |url=https://api.parliament.uk/historic-hansard/commons/1854/may/04/royal-military-asylum |website=api.parliament.uk |access-date=12 December 2023}}</ref><ref>{{cite web |title=Royal Military Asylum – Sotonopedia |url=http://sotonopedia.wikidot.com/page-browse:royal-military-asylum |website=sotonopedia.wikidot.com |access-date=12 December 2023}}</ref> and Yolland was put in charge, but Hall sent him off to Ireland so that when Hall left in 1854 Yolland was again passed over in favour of Major [[Henry James (British Army officer)|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]].<ref>{{cite web |title=Records of the Ordnance Survey of Great Britain |website=National Archives |url=https://discovery.nationalarchives.gov.uk/details/r/C221}}</ref>
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 [[George Biddell Airy|Airy]]'s spheroid in 1858, completing the [[Principal Triangulation of Great Britain|Principal Triangulation]].<ref>{{harvnb |Seymour |1980 |p=139}}</ref> The following year, he completed an initial [[levelling]] of the country.<ref>{{harvnb |Seymour |1980 |p=145}}</ref>
===Great Britain "County Series"===
{{Main|Ordnance Survey Great Britain County Series}}
{{Infobox UK legislation
| short_title = Ordnance Survey Act 1841
| type = Act
| parliament = Parliament of the United Kingdom
| long_title = An Act to authorize and facilitate the Completion of a Survey of Great Britain, Berwick upon Tweed, and the Isle of Man.
| year = 1841
| citation = [[4 & 5 Vict.]] c. 30
| introduced_commons =
| introduced_lords =
| territorial_extent =
| royal_assent = 21 June 1841
| commencement =
| expiry_date =
| repeal_date =
| amends =
| replaces =
| amendments = {{ubli|[[Statute Law Revision Act 1874 (No. 2)]]|[[Summary Jurisdiction Act 1884]]}}
| repealing_legislation =
| related_legislation =
| status = Partially_Repealed
| legislation_history =
| theyworkforyou =
| millbankhansard =
| original_text = https://www.legislation.gov.uk/ukpga/Vict/4-5/30/enacted
| revised_text =
| use_new_UK-LEG = yes
| UK-LEG_title = Ordnance Survey Act 1841
| collapsed = yes
}}
[[File:Ellis martin 5th series.png|thumb|The cover of the 5th series OS map Chelmsford and Southend sheet 108. Art by [[Ellis Martin]]]]
After the Ordnance Survey published its [[Ordnance Survey Ireland#History|first large-scale maps of Ireland]] in the mid-1830s, the [[Tithe 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 '''{{visible anchor|Ordnance Survey Act 1841}}''' ([[4 & 5 Vict.]] c. 30).<ref>{{cite web |url=https://www.legislation.gov.uk/ukpga/Vict/4-5/30/contents |title=Ordnance Survey Act 1841 |publisher=UK Parliament |website=legislation.gov.uk |access-date=2023-01-04 |archive-date=4 January 2023 |archive-url=https://web.archive.org/web/20230104105500/https://www.legislation.gov.uk/ukpga/Vict/4-5/30/contents |url-status=live }}</ref> 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<ref>{{cite web |url= http://www.london-fire.gov.uk/about_us/our_history/key_dates.asp |archive-url= https://web.archive.org/web/20080618055617/http://www.london-fire.gov.uk/about_us/our_history/key_dates.asp |archive-date=18 June 2008 |title=Key dates |publisher=London Fire Brigade}}</ref> 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 (Ordnance Survey)|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 [[facsimile]]s of nationally important manuscripts. Between 1861 and 1864, a facsimile of the [[Domesday Book]] was issued, [[Ancient counties of England|county]] by county; and a facsimile of the [[Gough Map]] was issued in 1870.
From the 1840s, the Ordnance Survey concentrated on the Great Britain "[[Ordnance Survey Great Britain County Series|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). In 1854, "twenty-five inch" maps were introduced with a scale of 1:2500 (25.344 inches to the mile) and the six inch maps were then based on these twenty-five inch maps. The first edition of the two scales was completed by the 1890s, with a second edition completed in the 1890s and 1900s. 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.{{sfn|Oliver|2005|p={{page needed |date=November 2017}} }}{{sfn|Oliver|Hellyer|2002|p={{page needed |date=November 2017}} }} Meanwhile, publication of the one-inch to the mile series for Great Britain was completed in 1891.
From the late 19th century to the early 1940s, the OS produced many "restricted" versions of the County Series maps and other War Department sheets for [[War Office]] purposes, in a variety of large scales that included details of military significance such as dockyards, naval installations, fortifications and military camps. Apart from a brief period during the disarmament talks of the 1930s, these areas were left blank or incomplete on standard maps. The War Department 1:2500s, unlike the standard issue, were [[Contour line|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.
=== City and town mapping, 19th and early 20th century ===
From 1824, the OS began a 6-inch (1:10,560) survey of Ireland for taxation purposes but found this to be inadequate for urban areas and adopted the five-foot scale (1:1056) for Irish cities and towns.{{sfn|Kain|Oliver|2015|p=201}} From 1840, the six-inch standard was adopted in Great Britain for the un-surveyed northern counties and the 1:1056 scale also began to be adopted for urban surveys.{{sfn|Kain|Oliver|2015|p=201}} Between 1842 and 1895, [[Ordnance Survey Great Britain County Series#Ordnance Survey Town Plans|some 400 towns]] were mapped at 1:500 (126 inches), 1:528 (120 inches, "10 foot scale") or 1:1056 (60 inches), with the remaining towns mapped at 1:2500 (~25 inches).{{sfn|Kain|Oliver|2015|p=14}} In 1855, the Treasury authorised funding for 1:2500 for rural areas and 1:500 for urban areas.{{sfn|Kain|Oliver|2015|p=217}} The 1:500 scale was considered more 'rational' than 1:528 and became known as the "sanitary scale" since its primary purpose was to support establishment of mains sewerage and water supply.{{sfn|Kain|Oliver|2015|p=217}} However, a review of the Ordnance Survey in 1892 found that sales of the 1:500 series maps were very poor and the Treasury declined to fund their continuing maintenance, declaring that any revision or new mapping at this scale must be self-financing.{{sfn|Kain|Oliver|2015|p=221}} Very few towns and cities saw a second edition of the town plans:{{sfn|Hindle|1998|pp=131–132}} by 1909 only fourteen places had paid for updates.{{sfn|Kain|Oliver|2015|p=220,221}} The review determined that revision of 1:2500 mapping should proceed apace.{{sfn|Kain|Oliver|2015|p=220}}
The most detailed mapping of London was the OS's 1:1056 survey between 1862 and 1872, which took 326 sheets to cover the capital;{{sfn|Kain|Oliver|2015|p=42}} a second edition (which needed 759 sheets because of urban expansion) was completed and brought out between 1891 and 1895.{{sfn|Kain|Oliver|2015|p=42}} London was unusual in that [[land registration]] on transfer of title was made compulsory there in 1900.{{sfn|Kain|Oliver|2015|p=222}} The 1:1056 sheets were partially revised to provide a basis for [[HM Land Registry]] index maps and the OS mapped the whole London County Council area (at 1:1056) at national expense.{{sfn|Kain|Oliver|2015|p=222}} Placenames from the second edition were used in 2016 by the [[GB1900]] project to crowd-source an open-licensed gazetteer of Great Britain.<ref>{{Cite Q|Q81201270}}</ref>
From 1911 onwards{{spaced ndash}}and mainly between 1911 and 1913{{spaced ndash}}the Ordnance Survey [[Enlarger|photo-enlarged]] many 1:2500 sheets covering built-up areas to 1:1250 (50.688 inches to the mile) for Land Valuation and Inland Revenue purposes: the increased scale was to provide space for annotations.{{sfn|Kain|Oliver|2015|p=222}} 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.{{sfn|Oliver|2005|p={{page needed |date=November 2017}} }}
===20th century===
[[File:Front cover of new popular edition.jpg|thumb|Front cover of a one-inch to the mile New Popular Edition, from 1945]]
[[File:London S.W. OS One-Inch 7th 170.jpg|thumb|Detailed scan of a complete 7th series sheet]]
During World War I, the Ordnance Survey was involved in preparing maps of [[Geography of France|France]] and [[Geography of Belgium|Belgium]]. During World War II, many more maps were created, including:
* 1:40,000 map of [[Antwerp]], Belgium
* 1:100,000 map of [[Brussels]], Belgium
* 1:5,000,000 map of [[Geography of South Africa|South Africa]]
* 1:250,000 map of [[Geography of Italy|Italy]]
* 1:50,000 map of north-east France
* 1:30,000 map of the Netherlands with manuscript outline of districts occupied by the [[German Army (Wehrmacht)|German Army]].
After the war, Colonel [[Charles Close]], then Director General, developed a 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.
In 1922, devolution in Northern Ireland led to the creation of the [[Ordnance Survey of Northern Ireland]] (OSNI) and the independence of the [[Irish Free State]] led to the creation of the [[Ordnance Survey of Ireland]], so the original Ordnance Survey pulled its coverage back to Great Britain. In 1935, the [[J. C. C. Davidson|Davidson]] Committee was established to review the Ordnance Survey's future. The new Director General, Major-General [[Malcolm MacLeod (scientist)|Malcolm MacLeod]], started the [[retriangulation of Great Britain]], an immense task involving the erection of concrete [[Triangulation station|triangulation pillars ("trig points")]] on prominent hilltops as infallible positions for theodolites. Each measurement made by theodolite during the retriangulation was repeated no fewer than 32 times.
The Davidson Committee's final report set the Ordnance Survey on course for the 20th century. The metric [[Ordnance Survey National Grid|national grid reference system]] was launched and a 1:25000-scale series of maps was introduced. The one-inch maps continued to be produced until the 1970s, when they were superseded by the 1:50000-scale series{{spaced ndash}}as proposed by William Roy more than two centuries earlier.
The 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 [[Southampton Blitz|Blitz]] devastated Southampton in November 1940 and destroyed most of [[Ordnance Survey buildings, Southampton|the Ordnance Survey's city centre offices]].<ref>{{cite web |title=Mapping the Southampton Blitz 70 years on |url=http://blog.ordnancesurvey.co.uk/2010/11/mapping-the-southampton-blitz-70-years-on/ |publisher=Ordnance Survey |access-date=19 June 2012 |date=30 November 2010 |archive-date=8 June 2012 |archive-url=https://web.archive.org/web/20120608015344/http://blog.ordnancesurvey.co.uk/2010/11/mapping-the-southampton-blitz-70-years-on/ |url-status=live }}</ref><ref>{{cite news |title=Southampton Blitz: Ordnance Survey map of bomb sites |url=http://news.bbc.co.uk/local/hampshire/hi/people_and_places/history/newsid_9232000/9232001.stm |publisher=BBC |access-date=19 June 2012 |date=30 November 2010 |archive-date=3 January 2013 |archive-url=https://web.archive.org/web/20130103070749/http://news.bbc.co.uk/local/hampshire/hi/people_and_places/history/newsid_9232000/9232001.stm |url-status=live }}</ref> 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 [[Invasion of Normandy|its invasion]]. Until 1969, the Ordnance Survey largely remained at its Southampton city centre HQ and at temporary buildings in the suburb of [[Maybush]] nearby, 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 city's court complex.
The new head office building was designed by the [[Ministry of Works (United Kingdom)|Ministry of Public Building and Works]] for 4000 staff, including many new recruits who were taken on in the late 1960s and early 1970s as draughtsmen and surveyors.{{Citation needed|date=September 2010}} The buildings originally contained factory-floor space for photographic processes such as [[heliozincography]] and map printing, as well as large buildings for storing flat maps. Above the industrial areas were extensive office areas. The complex was notable for its concrete mural. ''Celestial'', by sculptor [[Keith McCarter]]<ref name="Major">{{cite news |last1=Major |first1=Kirsty |title=How did a giant sculpture end up gathering moss in a field? |url=https://www.theguardian.com/artanddesign/2022/dec/15/keith-mccarter-concrete-mural-celestial-milton-keynes-field |access-date=15 December 2022 |work=[[The Guardian]] |date=15 December 2022 |language=en |archive-date=15 December 2022 |archive-url=https://web.archive.org/web/20221215120606/https://www.theguardian.com/artanddesign/2022/dec/15/keith-mccarter-concrete-mural-celestial-milton-keynes-field |url-status=live }}</ref> and the concrete elliptical paraboloid shell roof over the staff restaurant building.
In 1995, the 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.<ref name="ordnancesurvey.co.uk" /> By the late 1990s technological developments had eliminated the need for vast areas for storing maps and for making printing plates by hand. Although there was a small computer section at the 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 machine) had also rendered the photographic platemaking areas obsolete. Part of the latter was converted into a new conference centre in 2000, which was used for internal events and also made available for external organisations to hire.
The Ordnance Survey became an [[Executive Agency]] in 1990, making the organisation independent of ministerial control.<ref>Fraser Taylor 1998, p. 4</ref> In 1999 the agency was designated a [[trading fund]], required to cover its costs by charging for its products and to remit a proportion of its profits to the Treasury.<ref>{{cite web |url=https://www.ordnancesurvey.co.uk/documents/legal/os-shareholder-framework-document.pdf |title=Ordnance Survey Shareholder Document |author=<!--Not stated--> |website=www.ordnancesurvey.co.uk |publisher=Ordnance Survey |access-date=27 July 2020 |archive-date=27 July 2020 |archive-url=https://web.archive.org/web/20200727150849/https://www.ordnancesurvey.co.uk/documents/legal/os-shareholder-framework-document.pdf |url-status=live }}</ref>
===21st century===
[[File:Ordnance Survey HQ.jpg|thumb|left|Former Ordnance Survey headquarters in [[Maybush]], [[Southampton]], used from 1969 until 2011]]
[[File:Geograph 2222919 Ordnance Survey's new HQ.jpg|thumb|Headquarters in Adanac Park opened in 2011]]
In 2010, OS announced that printing and warehouse operations were to be outsourced,<ref name="ordnancesurvey.co.uk" /> ending over 200 years of in-house printing.<ref name="PrintWeek 6 September 2010">{{cite web |last=Morris |first=Helen |title=BT&D awarded map contract as Ordnance Survey bows out of print |url=http://www.printweek.com/print-week/news/1128411/bt-awarded-map-contract-ordnance-survey-bows-print |date=6 September 2010 |work=[[PrintWeek]] |access-date=9 September 2015 |archive-date=25 January 2016 |archive-url=https://web.archive.org/web/20160125082627/http://www.printweek.com/print-week/news/1128411/bt-awarded-map-contract-ordnance-survey-bows-print |url-status=live }}</ref> The Frome-based firm Butler, Tanner and Dennis (BT&D) secured its printing contract.<ref>{{Cite news |url=https://www.bbc.com/news/uk-england-somerset-11183624 |title=Frome company secures OS map contract |date=6 September 2010 |newspaper=BBC News |language=en-GB |access-date=31 January 2017 |archive-date=22 May 2017 |archive-url=https://web.archive.org/web/20170522034643/http://www.bbc.com/news/uk-england-somerset-11183624 |url-status=live }}</ref> As already stated, large-scale maps had not been printed at the Ordnance Survey since the common availability of [[Geographic information system|geographical information system]]s (GISs), but, until late 2010, the ''OS Explorer'' and ''OS Landranger'' series were printed in Maybush.
In April 2009 building began of a new head office in Adanac Park on the outskirts of Southampton.<ref>{{cite web |title=Ordnance Survey breaks ground at Adanac Park |publisher=Ordnance Survey |date=3 April 2009 |url=http://www.ordnancesurvey.co.uk/about/news/2009/groundbreaking.html |access-date=17 December 2009 |archive-date=11 January 2014 |archive-url=https://web.archive.org/web/20140111150436/http://www.ordnancesurvey.co.uk/about/news/2009/groundbreaking.html |url-status=live }}</ref> By 10 February 2011 virtually all staff had relocated to the new "Explorer House" building and the old site had been sold off and redeveloped. [[Prince Philip, Duke of Edinburgh|Prince Philip]] officially opened the new headquarters building on 4 October 2011.<ref>{{cite web |title=Duke opens new Ordnance Survey head office |url=http://www.ordnancesurvey.co.uk/oswebsite/news/2011/10/duke-opens-new-ordnance-survey-building.html |publisher=Ordnance Survey |access-date=21 June 2012 |date=5 October 2011 |archive-date=13 July 2012 |archive-url=https://web.archive.org/web/20120713165137/http://www.ordnancesurvey.co.uk/oswebsite/news/2011/10/duke-opens-new-ordnance-survey-building.html |url-status=live }}</ref>
On 22 January 2015 plans were announced for the organisation to move from a trading fund model to a government-owned [[limited company]], with the move completed in April 2015. The organisation remains fully owned by the UK government and retains many of the features of a public organisation.<ref>{{cite web |title=Ordnance Survey set to become a Government owned company |publisher=Ordnance Survey |date=22 January 2015 |url=http://www.ordnancesurvey.co.uk/about/news/2015/os-set-to-become-government-owned-company.html |access-date=22 January 2015 |archive-date=22 January 2015 |archive-url=https://web.archive.org/web/20150122172030/http://www.ordnancesurvey.co.uk/about/news/2015/os-set-to-become-government-owned-company.html |url-status=live }}</ref><ref>{{cite web |title=Ordnance Survey Change in Operating Model |publisher=UK Parliament |date=22 January 2015 |url=http://www.parliament.uk/business/publications/written-questions-answers-statements/written-statement/Commons/2015-01-22/HCWS215/ |access-date=22 January 2015 |archive-date=23 January 2015 |archive-url=https://web.archive.org/web/20150123005435/http://www.parliament.uk/business/publications/written-questions-answers-statements/written-statement/Commons/2015-01-22/HCWS215/ |url-status=live }}</ref> In September 2015 the history of the Ordnance Survey was the subject of a [[BBC Four]] TV documentary entitled ''A Very British Map: The Ordnance Survey Story''.<ref name="BBC Timeshift Series 15 Episode 2">{{cite episode |title= A Very British Map: The Ordnance Survey Story |url= http://www.bbc.co.uk/programmes/b06b36q3 |series=Timeshift |station=[[BBC Four]] |airdate= 9 September 2015}}</ref>
On 10 June 2019 the [[Department for Business, Energy and Industrial Strategy]] (BEIS) appointed Steve Blair as the [[Chief Executive]] of the Ordnance Survey.<ref>{{cite web |title=Steve Blair to join Ordnance Survey as new Chief Executive |url=https://www.os.uk/news/steve-blair-ceo/ |website=Ordnance Survey |access-date=26 February 2020 }}{{Dead link|date=August 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref>{{see also|Directors of the Ordnance Survey}}</ref> The Ordnance Survey supported the launch of the [[Slow Ways]] initiative, which encourages users to walk on lesser used paths between UK towns.<ref>{{Cite news|last=Cox|first=Roger|date=25 May 2021|title=Slow Ways project shows how covid made us re-think urban environment|publisher=The Scotsman|url=https://www.scotsman.com/lifestyle/outdoors/slow-ways-project-shows-how-covid-made-us-re-think-urban-environment-3249941|access-date=29 August 2021|archive-date=29 August 2021|archive-url=https://web.archive.org/web/20210829105536/https://www.scotsman.com/lifestyle/outdoors/slow-ways-project-shows-how-covid-made-us-re-think-urban-environment-3249941|url-status=live}}</ref> On 7 February 2023, ownership of Ordnance Survey Ltd passed to the newly formed [[Department for Science, Innovation and Technology]].<ref>{{cite web |title=Making Government Deliver for the British People |url=https://www.gov.uk/government/publications/making-government-deliver-for-the-british-people/making-government-deliver-for-the-british-people-html |website=gov.uk |publisher=UK Government |date=2023-02-07 |access-date=2023-04-01 |archive-date=31 March 2023 |archive-url=https://web.archive.org/web/20230331020803/https://www.gov.uk/government/publications/making-government-deliver-for-the-british-people/making-government-deliver-for-the-british-people-html |url-status=live }}</ref>
==Map range==
[[File:Ordnance Survey maps, W.H. Smith, Enfield.jpg|thumb|Ordnance Survey maps on sale]]
The Ordnance Survey produces a large range of paper maps and [[digital mapping]] products.
===OS MasterMap===
The Ordnance Survey's flagship digital product, launched in November 2001, is ''[[OS MasterMap]]'', a database that records, in one continuous digital map, every fixed feature of Great Britain larger than a few metres. Every feature is given a unique [[TOID]] (TOpographical IDentifier), a simple identifier that includes no semantic information. Typically, each TOID is [[Polygon mesh|associated with a polygon that represents the area]] on the ground that the feature covers, in [[Ordnance Survey National Grid|National Grid]] coordinates.
OS MasterMap is offered in themed layers, each linked to a number of TOIDs. In September 2010, the layers were:
;Topography
: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.
;Integrated transport network
:A link-and-node network of transport features such as roads and railways. This data is at the heart of many [[Satellite navigation|satnav]] systems. In an attempt to reduce the number of [[Heavy goods vehicle|HGV]]s using unsuitable roads, a data-capture programme of "Road Routing Information" was undertaken by 2015,<ref>{{cite web|url=https://www.ordnancesurvey.co.uk/blog/2016/05/how-can-os-data-help-with-safe-routing-for-hgvs/|title=How can OS data help with safe routing for HGVs?|date=3 May 2016|first=Gemma|last=Nelson|website=Ordnance Survey|access-date=22 June 2019|archive-date=23 June 2019|archive-url=https://web.archive.org/web/20190623000505/https://www.ordnancesurvey.co.uk/blog/2016/05/how-can-os-data-help-with-safe-routing-for-hgvs/|url-status=live}}</ref> aiming to add information such as height restrictions and one-way streets.
;Imagery
:[[Orthophoto|Orthorectified aerial photography]] in raster format.
;Address
:An overlay adding every address in the UK to other layers.
;Address 2
:Adds further information to the Address layer, such as addresses with multiple occupants (blocks of flats, student houses, etc.) and objects with no postal addresses, such as fields and electricity substations.
ITN was withdrawn in April 2019 and replaced by OS MasterMap Highways Network.<ref>{{cite web|url=https://www.ordnancesurvey.co.uk/search?term=ITN|title=ITN product withdrawal|website=Ordnance Survey|access-date=19 May 2021|archive-date=19 May 2021|archive-url=https://web.archive.org/web/20210519093941/https://www.ordnancesurvey.co.uk/search?term=ITN|url-status=live}}</ref>
The Address layers were withdrawn in about 2016 with the information now being available in the AddressBase products<ref>{{cite web|url=https://www.ordnancesurvey.co.uk/business-government/address-data|title=Address Data|website=Ordnance Survey|access-date=19 May 2021|archive-date=19 May 2021|archive-url=https://web.archive.org/web/20210519093938/https://www.ordnancesurvey.co.uk/business-government/address-data|url-status=live}}</ref> – so as of 2020, MasterMap consists of Topography and Imagery. 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.
The Ordnance Survey states that thanks to continuous review, ''OS MasterMap'' data is never more than six months out of date. The scale and detail of this mapping project is unique.{{Citation needed|date=September 2010}} By 2009, around 440 million TOIDs had been assigned, and the database stood at 600 gigabytes in size.<ref>[http://www.ordnancesurvey.co.uk/business-and-government/public-sector/mapping-agreements/index.html "Public sector mapping agreements | Business and government"]. {{Webarchive|url=https://web.archive.org/web/20130930064728/http://www.ordnancesurvey.co.uk/business-and-government/public-sector/mapping-agreements/index.html |date=30 September 2013 }}. Ordnance Survey. Retrieved on 12 April 2014.</ref> As of March 2011, OS claims 450 million TOIDs.<ref>[http://www.ordnancesurvey.co.uk/business-and-government/products/mastermap-products.html "OS MasterMap products | Business and government"]. {{Webarchive|url=https://web.archive.org/web/20130930073433/http://www.ordnancesurvey.co.uk/business-and-government/products/mastermap-products.html |date=30 September 2013 }}. Ordnance Survey. Retrieved on 12 April 2014.</ref> As of 2005, ''OS MasterMap'' was at version 6; 2010's version 8 includes provision for Urban Paths (an extension of the "integrated transport network" layer) and pre-build address layer. All these versions have a similar [[Geography Markup Language|GML]] schema.
===Business mapping===
The 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 the 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''
:The Ordnance Survey's most detailed mapping showing individual buildings and other features in a [[Vector graphics|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 so-called "layers" such as the aerial imagery, transport and postcode. The principal layer is the topographic layer.
;''OS VectorMap Local''
:A customisable vector product at 1:10,000 scale.
;''Meridian 2, Strategi''
: Mid-scale mapping in vector format.
;''Boundary-Line''
: Mapping showing administrative boundaries such as counties, parishes and [[Wards and electoral divisions of the United Kingdom|electoral wards]].
;''Raster versions of leisure maps''
: 1:10,000, 1:25,000, 1:50,000, 1:250,000 scale raster
===Leisure maps===
[[File:Ordnance Survey National Grid.svg|thumb|upright=1.4|Illustration of the Ordnance Survey National Grid coordinate system, with [[Royal Observatory Greenwich]] as an example]]
OS's range of leisure maps are published in a variety of scales:
{| class="wikitable"
|+ ''Tour'' scales and titles as of July 2021
|-
! Number !! Scale !! Title
|-
| 1 || 1:100 000|| Cornwall
|-
| 3|| 1:110 000 || Lake District & Cumbria
|-
| 4|| 1:100 000|| Peak District & Derbyshire
|-
| 5|| 1:130 000|| Devon & Somerset West
|-
| 8|| 1:100 000|| The Cotswolds & Gloucestershire
|-
| 10|| 1:175 000|| North & Mid Wales
|-
| 11|| 1:175 000|| South & Mid Wales
|-
| 12|| 1:500 000|| Scotland
|}
;''Tour'' {{nobold|{{smaller|({{circa|1:100,000|lk=yes}}, 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 maps have sky-blue covers and there are eight sheets in the series. Scales vary:
;''OS Landranger'' {{nobold|{{smaller|(1:50,000)}}}}
: 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 the ''Explorer'' maps, but with less detail.
;''OS Landranger Active'' {{nobold|{{smaller|(1:50,000)}}}}
: Select ''OS Landranger'' maps available in a plastic-[[Lamination|laminated]] waterproof version, similar to the ''OS Explorer Active'' range. {{As of|2009|10}}, 25 of the 204 ''Landranger'' maps were available as ''OS Landranger Active'' maps.
;''OS Explorer'' {{nobold|{{smaller|(1:25,000)}}}}
: Specifically designed for walkers and cyclists. They have orange covers, and 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 the Ordnance Survey publish and cover all types of footpaths and most details of the countryside for easy navigation. The ''OL'' branded sheets within the Explorer series show areas of greater interest (including the [[Lake District]], the [[Black Mountains, Wales|Black Mountains]], etc.) with an enlarged area coverage. They appear identical to the ordinary ''Explorer'' maps, except for the numbering and a little yellow mark on the corner (a relic of the old ''Outdoor Leisure'' series). The ''OS Explorer'' maps, together with the former ''Outdoor Leisure'' series, superseded the numerous green-covered ''Pathfinder'' maps. In May 2015 the Ordnance Survey announced that the new release of OL series maps would come with a mobile download version, available through a dedicated app on [[Android (operating system)|Android]] and [[iOS]] devices.<ref>{{cite web |title=Ordnance Survey maps undergo their greatest innovation for over 200 years |url=http://www.ordnancesurvey.co.uk/about/news/2015/os-maps-undergo-greatest-innovation-in-200-years.html |publisher=Ordnance Survey |access-date=20 May 2015 |archive-date=20 May 2015 |archive-url=https://web.archive.org/web/20150520194058/http://www.ordnancesurvey.co.uk/about/news/2015/os-maps-undergo-greatest-innovation-in-200-years.html |url-status=live }}</ref> It is expected that this will be rolled out to all the Explorer and Landranger series over time.
;''OS Explorer Active'' {{nobold|{{smaller|(1:25,000)}}}}
: ''OS Explorer'' and ''Outdoor Leisure'' maps in a plastic-laminated waterproof version.
;''Activity Maps''
: An experimental range of maps designed to support specific activities. The four map packs currently published are ''Off-Road Cycling Hampshire'' North, South, East and West. Each map pack contains 12 cycle routes printed on individual map sheets on waterproof paper. While they are based on the 1:25,000 scale maps, the scales have been adjusted so each route fits on a single A4 sheet.
;''Route'' {{nobold|{{smaller|(1:625,000; discontinued 2010)}}}}
: A double-sided map designed for long-distance road users, covering the whole of Great Britain.
;''Road'' {{nobold|{{smaller|(1:250,000; discontinued 2010)}}}}
: A series of eight sheets covering Great Britain, designed for road users.
The last two, along with fifteen ''Tour'' maps, were discontinued during January 2010 as part of a drive for cost efficiency following the [[Great Recession]].
The ''Road'' series was reintroduced in September 2016.<ref>{{cite web |url=https://www.ordnancesurvey.co.uk/shop/maps.html?cat%5B0%5D=20&cat%5B1%5D=138 |title=Maps |publisher=Ordnance Survey |access-date=15 September 2016 |archive-date=1 August 2023 |archive-url=https://web.archive.org/web/20230801232529/https://shop.ordnancesurvey.co.uk/maps/os-paper-maps/?cat%5B0%5D=20&cat%5B1%5D=138 |url-status=live }}</ref>
===App development===
In 2013, the Ordnance Survey released its first official app, OS MapFinder (still available, but no longer maintained), and has since added three more apps. In 2021, OS Maps added coverage in Australia.
;''OS Maps''
: Available on iOS and Android, the free to download app allows users to access maps direct to their devices, plan and record routes and share routes with others. Users can subscribe and download OS Landranger and OS Explorer high-resolution maps in 660dpi quality and use them without incurring roaming charges as maps are stored on the device and can be used offline – without Wi-Fi or mobile signal.
;''OS Maps Web''
: Available as a web page–it allows users to access maps from the web using modern web browsers, planning of custom routes and printing of maps is possible similarly to what the mobile applications can do
;''OS Locate''
: Launched in February 2014 and available on iOS and Android, the free app is a fast and highly accurate means of pinpointing a users exact ___location and displays grid reference, latitude, longitude and altitude. OS Locate does not need a mobile signal to function, so the inbuilt GPS system in a device can be relied upon.
===Custom products===
The Ordnance Survey also offers ''OS Custom Made'', a [[print-on-demand]] service based on digital raster data that allows a customer to specify the area of the map or maps desired. Two scales are offered{{spaced ndash}}1:50,000 (equivalent to 40 km by 40 km) or 1:25,000 (20 km by 20 km){{spaced ndash}}and the maps may be produced either folded or flat for framing or wall mounting. Customers may provide their own titles and cover images for folded maps.<ref>{{cite web |title=Custom Made |url=https://www.ordnancesurvey.co.uk/shop/custom-made-maps.html |publisher=Ordnance Survey |access-date=2 December 2013 |archive-date=3 January 2014 |archive-url=https://web.archive.org/web/20140103124044/https://www.ordnancesurvey.co.uk/shop/custom-made-maps.html |url-status=live }}</ref>
The Ordnance Survey also produces more detailed custom mapping to order, at 1:1,250 or 1:500 (''Siteplan''), from its large-scale digital data. Custom scales may also be produced from the enlargement or reduction of the existing scales.
===Educational mapping===
The Ordnance Survey supplies reproductions of its maps from the early 1970s to the 1990s for educational use. These are widely seen in schools both in Britain and in [[Changes in British sovereignty|former British colonies]], either as stand-alone geographic aids or as part of geography textbooks or workbooks.
During the 2000s, in an attempt to increase schoolchildren's awareness of maps, the Ordnance Survey offered a free ''OS Explorer Map'' to every 11-year-old in [[Primary education#United Kingdom|UK primary education]]. By the end of 2010, when the scheme closed, over 6 million maps had been given away.<ref>[http://www.ordnancesurvey.co.uk/about/news/2010/freemaps.html Schools urged to order free maps now! | About] {{Webarchive|url=https://web.archive.org/web/20140111150502/http://www.ordnancesurvey.co.uk/about/news/2010/freemaps.html |date=11 January 2014 }}. Ordnance Survey. Retrieved on 12 April 2014.</ref> The scheme was replaced by free access to the Digimap for Schools<ref>{{cite web |url=http://digimapforschools.edina.ac.uk/ |title=Digimap for Schools |website=EDINA |publisher=Ordnance Survey and University of Edinburgh |access-date=16 December 2024}}</ref> service provided by [[EDINA]] for eligible schools.<ref>{{cite web |url=http://blog.ordnancesurvey.co.uk/2010/09/large-scale-maps-become-child%E2%80%99s-play-with-digimap-for-schools/ |title=Maps are child's play with Digimap for Schools |author=Gemma<!--no surname given--> |date=September 24, 2010 |archive-url=https://web.archive.org/web/20101001012153/http://blog.ordnancesurvey.co.uk/2010/09/large-scale-maps-become-child%E2%80%99s-play-with-digimap-for-schools/ |archive-date=1 October 2010 |url-status=dead}}</ref>
With the trend away from paper products towards geographical information systems (GISs), the Ordnance Survey has been looking into ways of ensuring schoolchildren are made aware of the benefits of GISs and has launched "MapZone", an interactive child-orientated website featuring learning resources and map-related games. The Ordnance Survey publishes a quarterly journal, principally for geography teachers, called ''Mapping News''.
===Derivative and licensed products===
[[Bing Maps]] offers OS data as a layer for the whole of the UK.
[[George Philip (cartographer)|Philip's]] publishes OS data in its [[road atlas|road and street atlases]] in book format.<ref>{{cite news |title=Navigation: Find your way to a good map |url=https://www.thetimes.com/travel/destinations/europe-travel/navigation-find-your-way-to-a-good-map-3s8hsrx9r3m |date=13 June 2023 |language=en |access-date=13 June 2023 |archive-date=1 August 2023 |archive-url=https://web.archive.org/web/20230801232527/https://www.thetimes.co.uk/article/navigation-find-your-way-to-a-good-map-3s8hsrx9r3m |url-status=live }}</ref> One series of historic maps, published by Cassini, is a reprint of the Ordnance Survey first series from the mid-19th century but using the ''OS Landranger'' projection at 1:50,000 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 the Ordnance Survey to sell maps electronically. Several companies are now licensed to produce the popular scales (1:50,000 and 1:25,000) and their own derived datasets of the 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 the 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 individual map is more expensive than the equivalent paper version, but the price per square km falls rapidly with the size of coverage bought.
===Free access to historic mapping===
The [[National Library of Scotland]] provides free access to OS mapping from 1840 to 1970,<ref>{{cite web |title = About our map images |url = https://maps.nls.uk/about.html |publisher = National Library of Scotland |access-date = 22 April 2021 |archive-date = 11 April 2021 |archive-url = https://web.archive.org/web/20210411015143/https://maps.nls.uk/about.html |url-status = live }}</ref> in a variety of scales from 1:1056 "five foot" maps of London to 1:625,000 "ten mile" national planning maps.<ref>{{cite web |title = Ordnance Survey Maps, London, Five feet to the Mile, 1893–1896 |url = https://maps.nls.uk/geo/find/#zoom=6&lat=52.58098&lon=-3.36622&layers=38&b=1&z=1&point=0,0 |publisher = National Library of Scotland |access-date = 22 April 2021 |archive-date = 22 April 2021 |archive-url = https://web.archive.org/web/20210422190233/https://maps.nls.uk/geo/find/#zoom=6&lat=52.58098&lon=-3.36622&layers=38&b=1&z=1&point=0,0 |url-status = live }}</ref>
In addition, SABRE Maps provides free access to OS mapping from the end of World War 1 to the 1970s at small and intermediate scale mapping, including 1:25000, One Inch, Half Inch, Quarter Inch and Ten Mile scales, usually with a wider coverage of individual revisions than the NLS.<ref name="About SABRE Maps">{{cite web|title=About SABRE Maps|url=https://www.sabre-roads.org.uk/maps/|publisher=SABRE|access-date = 4 May 2024}}</ref>
===History of 1:63360 and 1:50000 map publications===
{| class="wikitable"
|+Main OS Great Britain 1:63360 (1 inch to 1 mile) and 1:50000 publications<ref name=bl>{{cite web |title=Ordnance Survey: small scale maps |url=http://www.bl.uk/reshelp/findhelprestype/maps/guideordsurv/smallosmaps.html |publisher=[[British Library]] }}{{dead link|date=January 2025|bot=medic}}{{cbignore|bot=medic}}</ref><ref name=close>{{cite web |last1=Higley |first1=Chris |title=Index Sheets for Ordnance Survey Map Series |publisher=The Charles Close Society |url=https://charlesclosesociety.org/indexes |access-date=13 October 2019 |archive-date=13 October 2019 |archive-url=https://web.archive.org/web/20191013125835/https://charlesclosesociety.org/indexes |url-status=live }}</ref>
|-
! Edition<ref name=bl /> !! Publication dates<ref name=bl /> !! Scale<ref name=bl /> !! Coverage<ref name=close /><ref group=Notes>Coverage: E=England; W=Wales; S=Scotland</ref> !! No. of sheets<ref name=close /> !! Notes<ref name=bl />
|-
| Old Series (or First Edition<ref name=browne>{{cite book |last1=Browne |first1=John Paddy |title=Map Cover Art: A pictorial history of Ordnance Survey cover illustrations |year=1991|publisher=Ordnance Survey |isbn=978-0319--00234-6|pages=12–13}}</ref>)|| 1805–1874 || 1:63360 || EW || 110 || excluded Scotland; first published edition
|-
| New Series (or Second Edition<ref name=browne />) || 1872–1897 || 1:63360 || EWS || 360EW+131S || first using contour lines
|-
| Revised New Series || 1895–1904 || 1:63360 || EWS || 360EW+131S || some colour sheets available
|-
| Third Edition || 1903–1919 || 1:63360 || EWS || 360EW+131S || "Small sheet series"
|-
| Third Edition || 1906–1913 || 1:63360 || EWS || 152EW+131S || "Large sheet series" in colour; also district and tourist editions
|-
| Fourth Edition || 1911–1912 || 1:63360 || EWS || – || abandoned small sheet series
|-
| Popular Edition || 1919–1926 || 1:63360 || EWS || 146EW+92S || large sheets; often mistakenly called Fourth Edition
|-
| Fifth Edition || 1931–1939 || 1:63360 || part E || – || abandoned; many styles available
|-
| War Revisions || 1943–1945 || 1:63360 || part EW || – || based on fifth and abandoned sixth editions
|-
| New Popular (Sixth) Edition || 1945–1947 || 1:63360 || EW || 64–190 || excluded Scotland, national grid
|-
| Seventh Series || 1952–1973 || 1:63360 || EWS || 190 || rights of way shown; ten colours
|-
| Landranger Series || 1974–present || 1:50000 || EWS || 204 || ongoing revisions
|}
==Cartography and geodesy==
{{main|Ordnance Survey National Grid}}
[[File:British National Grid.svg|thumb|The Ordnance Survey maps of Great Britain use the [[Ordnance Survey National Grid]]]]
The Ordnance Survey's 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 point]]s): short (c. 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 [[orthophoto|orthorectified]] [[aerial photography|aerial photographs]], but large numbers of the triangulation pillars remain, many of them adopted by private land owners. The 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 being built. While original survey methods were largely manual, the current surveying task is simplified by the use of [[Global Navigation Satellite System]] technology, allowing the most precise surveying standards yet.<ref>{{cite web |title=Surveying guidelines |url=http://www.ordnancesurvey.co.uk/business-and-government/help-and-support/navigation-technology/os-net/surveying.html |publisher=Ordnance Survey |access-date=14 November 2013 |archive-date=4 October 2013 |archive-url=https://web.archive.org/web/20131004130348/http://www.ordnancesurvey.co.uk/business-and-government/help-and-support/navigation-technology/os-net/surveying.html |url-status=live }}</ref> The Ordnance Survey is responsible for a UK-wide network of [[Real-time kinematic positioning#CORS|continually operating GNSS stations]] known as "OS Net". These are used for surveying and other organisations can purchase the right to utilise the network for their own uses.<ref>{{cite web |title=Overview of OS Net |url=https://www.ordnancesurvey.co.uk/business-government/tools-support/os-net |publisher=Ordnance Survey |access-date=3 January 2023 |archive-date=3 January 2023 |archive-url=https://web.archive.org/web/20230103232125/https://www.ordnancesurvey.co.uk/business-government/tools-support/os-net |url-status=live }}</ref>
The Ordnance Survey still maintains a set of master [[Geodesy|geodetic]] reference points to tie Ordnance Survey [[Geodetic datum|geographic datum points]] to modern measurement systems such as [[Global Positioning System|GPS]]. Ordnance Survey maps of Great Britain use the [[Ordnance Survey National Grid]] rather than [[Geographic coordinate system#Geographic latitude and longitude|latitude and longitude]] to indicate position. The Grid is known technically as [[OSGB36]] (Ordnance Survey Great Britain 1936) and was introduced after the 1936–1953 retriangulation.<ref name="GuideCRSGB">{{cite web |title=A Guide to Coordinate Systems in Great Britain |url=https://www.ordnancesurvey.co.uk/documents/resources/guide-coordinate-systems-great-britain.pdf |publisher=Ordnance Survey |access-date=3 January 2023 |date=2020 |archive-date=24 September 2015 |archive-url=https://web.archive.org/web/20150924061607/http://www.ordnancesurvey.co.uk/docs/support/guide-coordinate-systems-great-britain.pdf |url-status=live }}</ref>
On the British mainland for recording heights the Ordnance Survey maintains an orthometric system referenced to [[Ordnance Datum|Ordnance Datum Newlyn]], which is a height datum defined by [[mean sea level]] as measured in [[Newlyn]], Cornwall, between 1915 and 1921.<ref name="GuideCRSGB"/><ref>{{cite journal |last1=Greaves |first1=Mark |title=OSGM15 and OSTN15: Updated transformations for UK and Ireland |journal=Geomatics World |date=2016 |url=https://www.ordnancesurvey.co.uk/documents/resources/updated-transformations-uk-ireland-geoid-model.pdf |access-date=3 January 2023 |archive-date=14 August 2022 |archive-url=https://web.archive.org/web/20220814184524/https://www.ordnancesurvey.co.uk/documents/resources/updated-transformations-uk-ireland-geoid-model.pdf |url-status=live }}</ref> In 2016 the Ordnance Survey redefined Ordnance Datum Newlyn causing a general upwards shift of circa 25mm; an effect of this included the [[Calf Top]] hill becoming a mountain.<ref name="bbc">{{cite web |title=Calf Top Cumbrian hill re-categorised as a mountain |url=https://www.bbc.co.uk/news/uk-england-cumbria-37289472 |website=[[BBC News]] |access-date=9 December 2022 |date=2016 |archive-date=9 December 2022 |archive-url=https://web.archive.org/web/20221209230011/https://www.bbc.co.uk/news/uk-england-cumbria-37289472 |url-status=live }}</ref><ref>{{cite web |title=OSGM15 – the new geoid for Britain |url=https://www.ordnancesurvey.co.uk/newsroom/blog/ostn15-new-geoid-britain |publisher=Ordnance Survey |access-date=10 December 2022 |date=2016 |archive-date=10 December 2022 |archive-url=https://web.archive.org/web/20221210134602/https://www.ordnancesurvey.co.uk/newsroom/blog/ostn15-new-geoid-britain |url-status=live }}</ref>
The Ordnance Survey's CartoDesign team performs a key role in the organisation, as the authority for cartographic design and development, and engages with internal and external audiences to promote and communicate the value of [[cartography]]. They work on a broad range of projects and are responsible for styling all new products and services.<ref>{{cite web |title=Carto Design team |url=http://www.ordnancesurvey.co.uk/resources/carto-design/index.html |publisher=Ordnance Survey |access-date=22 January 2014 |archive-date=2 January 2014 |archive-url=https://web.archive.org/web/20140102192915/http://www.ordnancesurvey.co.uk/resources/carto-design/index.html |url-status=live }}</ref>
==Research==
{{unreferenced section|date=December 2024}}
For several decades the Ordnance Survey has had a research department that is active in several areas of [[geographical information science]], including:
* [[Spatial cognition]]
* [[Cartographic generalization|Map generalisation]]
* Spatial data modelling
* [[Remote sensing]] and analysis of remotely sensed data
* Semantics and [[Ontology (information science)|ontologies]]
The 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 the Ordnance Survey's own research agenda.
== Data access ==
{{see also|Open Data in the UK}}
Ordnance Survey possesses a virtual government monopoly on geographic data in the UK,<ref>{{cite news |url=http://technology.guardian.co.uk/weekly/story/0,,1726229,00.html |last1=Arthur |first1=Charles |last2=Cross |first2=Michael |title=Give us back our crown jewels |newspaper=The Guardian |date=9 March 2006 |access-date=10 March 2006 |archive-date=17 March 2006 |archive-url=https://web.archive.org/web/20060317154140/http://technology.guardian.co.uk/weekly/story/0,,1726229,00.html |url-status=live }}</ref> but, although a government agency, it has been required to act as a [[trading fund]] (i.e. a commercial entity) from 1999 to 2015. This meant that it is supposed to be entirely self-funded from the commercial sale of its data and derived products whilst at the same time 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".<ref>{{cite book |last=Chorley |first=RRE |author-link=Roger Chorley, 2nd Baron Chorley |year=1987 |title=Handling Geographic Information. Report of the Committee of Enquiry chaired by Lord Chorley |place=London |publisher=HMSO}}</ref> The committee's final report, published in 1987 under the name of its chairman [[Roger Chorley, 2nd Baron Chorley|Roger Chorley]], stressed the importance of accessible geographic information to the UK and recommended a loosening of policies on distribution and cost recovery.
In 2007 the Ordnance Survey were criticised for contracting the public relations company Mandate Communications<ref>{{UK Parliament |date=1 May 2008 |place=Written Questions |url= https://www.theyworkforyou.com/wrans/?id=2008-05-01b.202287.h |column=668W |speaker=[[Greg Clark]] |title=Ordnance Survey: Mandate Communications}}</ref> to understand the dynamics of the [[Open Data in the United Kingdom|free data movement]] and discover which politicians and advisers continued to support their current policies.<ref>{{cite news |url=https://www.theguardian.com/technology/2008/aug/21/politicsandtechnology |title=Ordnance Survey hires PR company to lobby politicians |date=21 August 2008 |first=Michael |last=Cross |newspaper=The Guardian |access-date=15 December 2016 |archive-date=1 December 2016 |archive-url=https://web.archive.org/web/20161201230517/https://www.theguardian.com/technology/2008/aug/21/politicsandtechnology |url-status=live }}</ref>
===''OS OpenData''===
In response to the feedback from a consultation ''Policy options for geographic information from Ordnance Survey''<ref>{{cite web|url=http://www.communities.gov.uk/documents/corporate/pdf/1411177.pdf|archive-url=http://webarchive.nationalarchives.gov.uk/20120920010448/http://www.communities.gov.uk/documents/corporate/pdf/1411177.pdf|url-status=dead|archive-date=20 September 2012|access-date=22 June 2019|date=December 2009|title=Policy options for geographic information from Ordnance Survey|publisher=[[Department for Communities and Local Government]]}}</ref> the government announced that a package of Ordnance Survey data sets would be released for free use and re-use.<ref name="OSA">{{cite web |url= http://www.communities.gov.uk/publications/corporate/ordnancesurveyconresponse |archive-url= http://webarchive.nationalarchives.gov.uk/20120919132719/http://www.communities.gov.uk/publications/corporate/ordnancesurveyconresponse |url-status=dead |archive-date= 19 September 2012 |title= Policy options for geographic information from Ordnance Survey: Consultation – Government Response |publisher=[[Department for Communities and Local Government]]}}</ref> On 1 April 2010 the Ordnance Survey released<ref>{{cite news |url=http://www.ordnancesurvey.co.uk/about/news/2010/OpenData.html |title=Ordnance Survey launches OS OpenData in groundbreaking national initiative |publisher=Ordnance Survey |date=1 April 2010 |access-date=16 April 2010 |archive-date=27 September 2013 |archive-url=https://web.archive.org/web/20130927195559/http://www.ordnancesurvey.co.uk/about/news/2010/OpenData.html |url-status=live }}</ref> the brand ''OS OpenData''<ref>{{cite web |url=https://osdatahub.os.uk/downloads/open |title=OpenData Downloads |website=OS Data Hub |publisher=Ordnance Survey |access-date=16 December 2024}}</ref> under an attribution-only licence compatible with [[Creative Commons license|CC-BY]].<ref>{{cite web |url=http://www.ordnancesurvey.co.uk/oswebsite/docs/licences/os-opendata-licence.pdf |title=OpenData License Terms and Conditions |publisher=Ordnance Survey |access-date=5 April 2010 |archive-date=24 August 2011 |archive-url=https://web.archive.org/web/20110824150008/http://www.ordnancesurvey.co.uk/oswebsite/docs/licences/os-opendata-licence.pdf |url-status=live }}</ref> Various groups and individuals had campaigned for this release of data, but some were disappointed when some of the profitable datasets, including the leisure 1:50,000 scale and 1:25,000 scale mapping, as well as the low scale Mastermap were not included. These were withheld with the counter-argument that if licensees do not pay for OS data collection then the government would have to be willing to foot a £30 million per annum bill to obtain the future economic benefit of sharing the mapping.<ref>{{cite news |url=https://www.theguardian.com/news/datablog/2010/apr/02/ordnance-survey-open-data |title=The Ordnance Survey has opened up its map data for free after a long campaign. Find out what was released |newspaper=The Guardian |date=2 April 2010 |access-date=16 April 2010 |archive-date=7 April 2020 |archive-url=https://web.archive.org/web/20200407171347/https://www.theguardian.com/news/datablog/2010/apr/02/ordnance-survey-open-data |url-status=live }}</ref>
In mid-2013 the Ordnance Survey described an "enhanced" [[Linked data|linked-data]] service with a [[SPARQL]] 1.1-compliant endpoint and bulk-download options.<ref>{{cite press release |title=New Ordnance Survey Linked Data service proving popular with developers |url=http://www.directionsmag.com/pressreleases/new-ordnance-survey-linked-data-service-proving-popular-with-developers/340085 |date=17 July 2013 |access-date=28 July 2013 |publisher=Ordnance Survey |archive-url=https://web.archive.org/web/20130726181925/http://www.directionsmag.com/pressreleases/new-ordnance-survey-linked-data-service-proving-popular-with-developers/340085 |archive-date=26 July 2013 |url-status=dead }}</ref>
In June 2018, following the recommendations of the [[Geospatial Commission]], part of the [[Cabinet Office]],<ref>{{cite web|url=https://www.gov.uk/government/organisations/geospatial-commission|title=Geospatial Commission|access-date=22 June 2019|archive-date=22 June 2019|archive-url=https://web.archive.org/web/20190622225346/https://www.gov.uk/government/organisations/geospatial-commission|url-status=live}}</ref> it was announced that parts of OS Mastermap would be released under the [[Open Government Licence]].<ref>{{cite web|url=https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/716023/OSMM_narrative.pdf|title=MasterMap announcement|access-date=19 May 2021|archive-date=29 January 2021|archive-url=https://web.archive.org/web/20210129121920/https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/716023/OSMM_narrative.pdf|url-status=live}}</ref> These would include:
* property extents created from OS MasterMap Topography Layer
* TOIDs from OS MasterMap Topography Layer, by integration into OpenMap Local
Other data would be made available free up to small businesses (under a transaction threshold)
* OS MasterMap Topography Layer, including building heights and functional sites
* OS MasterMap Greenspace Layer
* OS MasterMap Highways Network
* OS MasterMap Water Network Layer
* OS Detailed Path Network
These are available through [[API]]s on the OS Data Hub.<ref>{{cite web |url=https://osdatahub.os.uk/|title=OS Data Hub|publisher=Ordnance Survey|access-date=16 December 2024}}</ref>
===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 the Ordnance Survey does not provide historical mapping on "free" terms, instead marketing commercially "enhanced" reproductions in partnership with companies including GroundSure and Landmark.
The [[National Library of Scotland]] has been developing its archive to make Ordnance Survey maps for all of Great Britain more easily available through their website,<ref>{{cite web |title=Ordnance Survey Maps |url=http://maps.nls.uk/os/ |publisher=National Library of Scotland |access-date=21 May 2015 |archive-date=27 May 2015 |archive-url=https://web.archive.org/web/20150527201628/http://maps.nls.uk/os/ |url-status=live }}</ref> whilst the [[Society for All British and Irish Road Enthusiasts]] (SABRE) also has a large easily available archive for large numbers of Ordnance Survey maps across all of Great Britain, often with almost complete complete sets of all relevant map revisions.<ref name="About SABRE Maps"/>
[[Wikimedia Commons]] has complete sets of scans of the Old/First series one-inch maps of England and Wales;<ref>{{cite web|title=Old/First series one-inch England and Wales|website=Wikimedia Commons|url=https://commons.wikimedia.org/wiki/Category:Ordnance_Survey_Old/First_series_England_and_Wales_1:63360_(full_sheets)|access-date=22 May 2018|archive-date=19 February 2021|archive-url=https://web.archive.org/web/20210219190904/https://commons.wikimedia.org/wiki/Category:Ordnance_Survey_Old/First_series_England_and_Wales_1:63360_(full_sheets)|url-status=live}}</ref> of the Old/First series one-inch maps of Scotland;<ref>{{cite web|title=Old/First Series one-inch Scotland|website=Wikimedia Commons|url=https://commons.wikimedia.org/wiki/Category:Ordnance_Survey_Old/First_series_Scotland_1:63360_(full_sheets)|access-date=22 May 2018|archive-date=15 May 2021|archive-url=https://web.archive.org/web/20210515181541/https://commons.wikimedia.org/wiki/Category:Ordnance_Survey_Old/First_series_Scotland_1:63360_%28full_sheets%29|url-status=live}}</ref> of the Seventh Series One-inch maps of Great Britain (1952–1967);<ref>{{cite web|title=Seventh Series one-inch Great Britain|website=Wikimedia Commons|url=https://commons.wikimedia.org/wiki/Category:Ordnance_Survey_Seventh_Series_Great_Britain_(1952_-_c1967)_1:63360_(full_sheets)|access-date=19 May 2018|archive-date=15 May 2021|archive-url=https://web.archive.org/web/20210515181514/https://commons.wikimedia.org/wiki/Category:Ordnance_Survey_Seventh_Series_Great_Britain_%281952_-_c1967%29_1:63360_%28full_sheets%29|url-status=live}}</ref> of the Third Edition quarter-inch maps of England and Wales;<ref>{{cite web|title=Third Edition quarter-inch England and Wales|website=Wikimedia Commons|url=https://commons.wikimedia.org/wiki/Category:Ordnance_Survey_Quarter-Inch_Third_Edition_England_and_Wales_(1919-1930)_1:253,440_(full_sheets)|access-date=5 July 2018|archive-date=15 May 2021|archive-url=https://web.archive.org/web/20210515181628/https://commons.wikimedia.org/wiki/Category:Ordnance_Survey_Quarter-Inch_Third_Edition_England_and_Wales_%281919-1930%29_1:253,440_%28full_sheets%29|url-status=live}}</ref> and of the Fifth Series quarter-inch maps of Great Britain.<ref>{{cite web|title=Fifth Series quarter-inch Great Britain|website=Wikimedia Commons|url=https://commons.wikimedia.org/wiki/Category:Ordnance_Survey_Quarter-Inch_Fifth_Series_(1962-_)_1:250,000_(full_sheets)|access-date=5 July 2018|archive-date=15 May 2021|archive-url=https://web.archive.org/web/20210515181649/https://commons.wikimedia.org/wiki/Category:Ordnance_Survey_Quarter-Inch_Fifth_Series_%281962-_%29_1:250,000_%28full_sheets%29|url-status=live}}</ref> These sets are complete in the sense of including at least one copy of each of the sheets in the series, not in the sense of including all revision levels.
== See also ==
{{too many see alsos|date=June 2025}}
{{portal|Maps}}
* {{anl|Admiralty chart}}
* {{anl|Alastair Macdonald (surveyor)}}
* {{anl|Benchmark (surveying)}}
* {{anl|Cartography}}
* {{anl|Directors of the Ordnance Survey}}
* {{anl|Geographers' A-Z Map Company}}
* {{anl|Geoinformatics}}
* {{anl|Great Trigonometric Survey}}
* {{anl|Grid reference}}
* {{anl|Hydrographic survey}}
* {{anl|Hydrography}}
* {{anl|International Map of the World}}
* {{anl|Irish national grid reference system}}
* {{anl|Martin Hotine}}
* {{anl|National Map Reading Week}}
* {{anl|National mapping agency}}
* {{anl|Ordnance datum}}
* {{anl|Ordnance Survey International}}
* {{anl|Ordnance Survey International|Directorate of Overseas Surveys}}
* {{anl|Ordnance Survey Ireland}}
* {{anl|Ordnance Survey National Grid}}
* {{anl|Ordnance Survey of Northern Ireland}}
* {{anl|Romer (tool)}}
* {{anl|United Kingdom Hydrographic Office}}
==References==
===Notes===
{{reflist|group=Notes}}
===Citations===
{{Reflist|refs=
<ref name="nls.uk">{{cite web|url= http://maps.nls.uk/os/6inch/os_info3.html|title= Ordnance Survey Maps Six-inch, 1st edition, Scotland, 1843–1882|website= National Library of Scotland|access-date= 12 April 2014|archive-date= 4 October 2013|archive-url= https://web.archive.org/web/20131004233814/http://maps.nls.uk/os/6inch/os_info3.html|url-status= live}}</ref>
<ref name="ordnancesurvey.co.uk">{{cite web |url=http://www.ordnancesurvey.co.uk/about/overview/history.html |title=Our history |website=Ordnance Survey |access-date=12 April 2014 |archive-date=11 January 2014 |archive-url=https://web.archive.org/web/20140111153635/http://www.ordnancesurvey.co.uk/about/overview/history.html |url-status=live }}</ref>
}}
===Sources===
{{refbegin}}
*{{cite book |editor-last=Fraser Taylor |editor-first=D. R. |date=1998 |title=Policy Issues in Modern Cartography |url=https://books.google.com/books?id=XznRE2jDn6UC&pg=PA6 |___location=Oxford |publisher=Pergamon Press |isbn=978-0080431116 |access-date=25 September 2020 |archive-date=1 August 2023 |archive-url=https://web.archive.org/web/20230801232528/https://books.google.com/books?id=XznRE2jDn6UC&pg=PA6 |url-status=live }}
*{{cite book |last=Hewitt |first=Rachel |year=2010 |title=Map of a Nation – A biography of the Ordnance Survey |place=London |publisher=[[Granta]] |isbn=978-1-847-08254-1 |url-access=registration |url=https://archive.org/details/mapofnationbiogr0000hewi }}
*{{cite book |last=Hindle |first=Paul |year=1998 |title=Maps for Historians |place=Chichester |publisher=[[The History Press|Phillimore & Co]] |isbn= 0-85033-934-0 |pages=114–115 }}
* {{cite book |last1=Kain |first1=Roger J. P. |last2=Oliver |first2=Richard R. |title=British Town Maps, A History |publisher=British Library |date=2015 |isbn=978-0-7123-5729-6 }}
*{{cite book |last=Margary |first=Harry |year=1992 |title= Old Series Ordnance Survey Maps of England and Wales |place=Lympne |isbn=0-903541-01-7 }}<!--, a series of eight books with explanatory introductions.-->
*{{cite book |last1=Oliver |first1=Richard |last2=Hellyer |first2=Roger |year=2002 |title=Ordnance Survey of Great Britain: Indexes to the 1:2500 and six-inch scales |place=Newtown, Montgomeryshire |publisher=David Archer }}
*{{cite book |last=Oliver |first=Richard |year=2005 |orig-year=1993 |title=Ordnance Survey Maps: a concise guide for historians |place=London |publisher=Charles Close Society |isbn=1870598245 }}
*{{cite book |last1=Owen |first1=Tim |last2=Pilbeam |first2=Elaine |year=1992 |title=Ordnance Survey – Map Makers to Britain Since 1791 |place=Southampton |publisher=Ordnance Survey |isbn=0-31-900249-7 |url=https://www.ordnancesurvey.co.uk/documents/resources/map-makers-britain-history.pdf |access-date=1 August 2023 |archive-date=3 November 2021 |archive-url=https://web.archive.org/web/20211103020553/https://www.ordnancesurvey.co.uk/documents/resources/map-makers-britain-history.pdf |url-status=live }}
*{{cite book |last=Porter |first=Whitworth |author-link=Whitworth Porter |year=1889 |title=History of the Corps of Royal Engineers |volume=I |publisher=Longmans, Green, and Co |___location=London |pages=167–68 |url=https://books.google.com/books?id=lqlBAAAAIAAJ }}
*{{cite book |title=A History of the Ordnance Survey |editor-last=Seymour |editor-first=W.A. |year=1980 |___location=Folkestone |publisher=Wm Dawson & Sons |url=https://www.ordnancesurvey.co.uk/documents/resources/os-history.pdf |access-date=11 December 2023 }}
*{{cite web |title=Homepage |publisher=Ordnance Survey |url=http://www.ordnancesurvey.co.uk/ |access-date=29 September 2005 |archive-date=16 October 2003 |archive-url=https://web.archive.org/web/20031016154458/http://www.ordnancesurvey.co.uk/ |url-status=live }}
*{{cite web |title=History of Cartography |publisher=University of Exeter |url=http://www.ex.ac.uk/geography/research/maphist.html |access-date=29 September 2005 |url-status=dead |archive-url=https://web.archive.org/web/20051128091010/http://www.ex.ac.uk/geography/research/maphist.html |archive-date=28 November 2005 }}
{{refend}}
==External links==
{{Commons category}}
* {{Official website}}
* [https://www.nationalarchives.gov.uk/help-with-your-research/research-guides/ordnance-survey Ordnance Survey research guide] – [[The National Archives (United Kingdom)|The National Archives]]
{{Department for Science, Innovation and Technology}}
{{Atlas}}
{{Visualization}}
{{authority control}}
[[Category:Ordnance Survey| ]]
[[Category:1791 establishments in Great Britain]]
[[Category:Cartography organizations]]
[[Category:Department for Science, Innovation and Technology]]
[[Category:Geodesy organizations]]
[[Category:Geographical databases in the United Kingdom]]
[[Category:Geography of Great Britain]]
[[Category:Geography organizations]]
[[Category:Government databases in the United Kingdom]]
[[Category:Government-owned companies of the United Kingdom]]
[[Category:Surveying organizations]]
[[Category:Maps of the United Kingdom]]
[[Category:National mapping agencies]]
[[Category:Organisations based in Southampton]]
[[Category:Organizations established in 1791]]
[[Category:Geographic data and information organisations in the United Kingdom]]
[[Category:Surveying of the United Kingdom]]
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