1.6 Million aerial photographs with associated sortie plots, cover traces, card indexes, base maps, contracts, calibration certificates covering 55 countries.
Alistair Macdonald (1996), 'Mapping the World: A History of the Directorate of Overseas Surveys 1946-1985', HMSO.
The Directorate of Colonial Surveys was founded by the Colonial Office in 1946 and its brief, at the outset of its thirty-eight years existence, was to fulfill two key purposes. Firstly, to provide national geodetic frameworks throughout the Colonial Empire that would not only contribute to understanding of the size and shape of the earth, but would constitute the basis of accurate mapping. Secondly, to produce such mapping using modern methods based on aerial photography.
In 1957, with the imminent decolonisation of many British territories, it was renamed the Directorate of Overseas Surveys (DOS). The remit of the organisation was expanded to include countries within and without the Commonwealth, and meant the Directorate's surveyors - based in Tolworth in suburban west London - ultimately surveyed fifty-five countries around the world. These included countries throughout Australasia and the Far East, the Indian Subcontinent, Middle East, Africa, Caribbean, South America, British Antarctic Territory and islands in the Pacific, Atlantic, Indian and Mediterranean.
Government reviews during the 1970s led to it being merging into the Ordnance Survey (OS) in 1984 whence it was known as the Overseas Surveys Directorate (OSD). In 1991, following completion of the last significant aid-funded mapping projects, its name was changed one final time to Ordnance Survey International and its main activity became consultancy, primarily in Eastern Europe. It was closed in 2001.
Records were held by DOS from creation until it was merged with Ordnance Survey. After a review in 2002, when it was decided it was no longer required for operational purposes, responsibility for the records passed to The National Archives. The 1st Print Library, definitive finding aids and air photo mosaic collection were transferred from The National Archives to the British Empire and Commonwealth Museum, Bristol, in 2002. In 2012, these were transferred to NCAP.
No catalogued finding aids available. Imagery can only currently be located with knowledge of exact sortie references.
Oxford University - Rhodes College Library: 2nd Print Library (an incomplete and lower-quality copy of the aerial photography).
The National Archives: Manuscript maps (hand-drawn originals); Survey records; 35mm slides of DOS activities and equipment; International boundary maps and files; DOS staff lists, field party address lists, photograph albums.
British Film Institue: DOS cine film collection.
British Antarctic Survey: Aerial photography from the 1st Print Library of British Antarctic Territory.
Other organisations: The original aerial films were transferred to the corresponding countries after the creation of cartography throughout the existence of DOS. An amount of record was transferred to the Royal Geographical Society, whilst the DOS Library was distributed amongst a number of libraries under the direction of The National Archives. The British Deposit Libraries hold copies of the mapping created by DOS.