What is Positional Improvement (PI)?
Where old methods focused on the relative accuracy of the distance measured between two points on a map and the true distance between the same two points; new surveying methods capture the absolute accuracy distance between the position of a point on a large scale map and assess its true position within the reference frame using Global Positioning Systems (GPS).
If you are having difficulty viewing the map, please contact our PI section on 028 9038 8416.
Latest PI Information
Update: 15 November 2013.
All sheets have now been positionally improved and are available to customers.
All positionally improved sheets have corresponding link files available for customers.