Positional accuracy improvement programme

Transforming your data

<<< Links files and statistics | Transformation software and services >>>

Updated January 2004

Link files contain before and after coordinate positions of points on a map tile and the feature code of the feature to which the link relates. They have been developed to be used with appropriate transformation software as an aid to moving customers' data in accordance to any shift patterns that have occurred in the map data as a result of positional accuracy improvement (PAI).

When you apply the link files and your chosen third party rubber sheeting software, you are advised to:

1. Optimise any parameter variables that are available within the software to obtain the most effective result for your data.
2. Set up a quality assurance system to confirm that the results from the transformation process are satisfactory to your business needs.
3. Transform your data only once.

To assist customers in discussion with system suppliers on transformation software using Ordnance Survey supplied link files, a questionnaire and a statement on the features of types of transformation are now available:

• View/download questionnaire (27Kb PDF)
• View/download Transformation features guide (35Kb PDF)