Spatial Data Models © Mahes Visvalingam, August 2002

Preface           

This web page has been created in response to a number of recent email enquiries and it will be extended to provide a fuller background on CISRG research of spatial data models.  The chapter was based on a set of lectures given to Computer Science and Geography students taking the Final Year option on Digital Cartography.

My chapter (Visvalingam, 1991) was a contribution to the debate on the choice of basic building blocks and spatial referencing systems for national archives of geo-referenced data.  Land surveyors were campaigning for land parcels corresponding to HMLR (Her Majesty's Land Registry) land parcels, service providers were pushing for street addresses while the market analysis services were lobbying for postcodes.  My perspective was based on CISRG research undertaken on behalf of the Ordnance Survey (OS) of Great Britain.  I reviewed the various issues involved in the design of BSUs and proposed that the national archive of topographic data should be based on primitive regions, i.e. the units of uncut space, onto which all user-perceived objects could be mapped and cross-linked.  This idea is now at the heart of the new OS MasterMap^TM, which uses unique Topographic Identifiers (TOID) and National Grid co-ordinates for management and cross-linking of disparate geo-referenced databases. Further pages will be added to this web to provide some background on feasibility studies undertaken in collaboration with the OS on topological models.

• Areal Units and the Linking of Data : some conceptual issues (Visvalingam, 1991)
• Area Topology (under construction)

Cartographic Information Systems Research Group, University of Hull