Who Needs Cartographers?

Abstract

In 1791, the British Government instructed the military to map the south of England at a scale of one inch to the mile (1:63 360) in preparation for an expected invasion attempt from French forces. Kent, in the extreme south-east of the country, was considered the most vulnerable area for attack and that was the subject area for the first map, completed in 1801. Thus was born Ordnance Survey and, within a few years, the practical value of appropriate maps had become more widely appreciated for the transfer and management of land, civil engineering projects and scientific applications such as the mapping of geological and archaeological information. By the mid-nineteenth century Ordnance Survey had assumed its modern role of providing the national mapping needs for the whole of Great Britain (that is England, Scotland and Wales) (Harley, 1975). Today, we are a wholly civilian, independent Government department that became a public-sector Trading Fund in 1999, giving us more commercial flexibility than we previously enjoyed but also greater responsibility for our finances and a commitment to making a profit. Ultimately, all our products and services rely on a network of around 300 surveyors employing ground and air survey techniques to maintain the ‘master map’ of the country at nominal capture scales of 1:1250 for urban areas, 1:2500 for rural areas and 1:10 000 for mountain and moorland areas, comprising in total some 230 000 maps. We began digitising these maps in the early 1970s in a fairly small way, the initial objective being to improve map production efficiencies and to produce electronic versions of the existing paper maps. No-one could foresee then the enormous explosion in the demand for, and use of, geographic information (GI) that we see around us today. The programme accelerated through the 1980s and was completed in 1995, to make Britain the first country in the world to compile such a detailed national vector database. The tiled and relatively unstructured (point and line) geometry of the original database was not only too coarse for effective data manipulation – now possible through today’s technological advances – but also did not meet increasing customer needs. Consequently, we have since completed a major re-engineering programme to develop the detailed topographic information, creating polygons to represent actual features with inferred links, resulting in some 440 million real-world objects. Every day surveyors, wherever they may be working in the country, download around 5 000 changes directly to the database using the latest technologies; these changes are then made available to our customers on the following day. This database update regime is maintained by change intelligence directing the data capture or by cyclic revision and ensures that any major changes to roads, building development and so on are recorded within six months of their ground completion.