Ordnance Survey – Great Britain's national mapping agency
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Positional accuracy improvement programme
The Ordnance Survey PAI Programme completed 31 March 2006. This national programme was developed to enable the capture of 1:2500 data to a greater absolute accuracy (absolute accuracy is the position of features in relation to the Ordnance Survey National Grid). The PAI Programme has resulted in an improved and more consistent accuracy standard of mapping data for rural areas. A significant benefit to come from programme completion is a better relationship between Ordnance Survey 1:2500 scale map data and customers own GPS positioned information.
Link file improvement - June 2006.
Ordnance Survey is undertaking improvements to a small number of link files. It is important that those undertaking PAI migration now or planning to do so within the next 3 months know which files are being enhanced.
PAI Toolbox
To assist those undertaking a PAI programme on their own data the PAI Toolbox has been created to make this task easier.
Without being prescriptive as to how PAI should be implemented, the migration process has been broken down into logical phases. Basic instructions are supplied for each of these phases with links to further information that is relevant to this stage of the process.
PAI test data
To help with comparing vendor systems and services for migrating customer data in line with PAI, a variety of test data is available for download.
PAI map tile listing now available
A text file containing all map tiles affected by both the Rural Towns and Other Rural Areas programmes is available for download. The file can be imported into a GIS to display the PAI programme graphically.