PAI Warp

I n t r o d u c t i o n

At present Ordnance Survey (O.S.) are running the PAI programme to help improve the accuracy of surveyed features in relation to the Ordnance Survey National Grid. How will this effect you and your company ?

The PAI programme means that features shown on an Ordnance Survey background map may change position after being re-surveyed (PAI'ed) by Ordnance Survey.

In 'simple' terms - if you currently use O.S. background map data, over which plant/asset data has been placed. When PAI updates are received from Ordnance Survey - the position of your exisiting plant/asset data may need to be re-positioned to match the new background maps. The Ordnance Survey have more information about Positional Accuracy Improvement.

W a r p S o f t w a r e

dhp11 Ltd and Intelliscan have developed a system allowing existing plant/asset data to be re-positioned using the pre/post PAI O.S. background maps. The name of this system is called 'Warp' - it allows an organisation to re-align their existing plant/asset data, against new (post PAI) O.S. background maps. The software allows the operator to view existing plant/asset data against old (pre-pai) and new (post-pai) O.S. map background(s), at the same time.

This allows the operator to see clearly - any 'shift' that may have occured between the pre/post PAI O.S. background maps, and the implications this may have on any existing plant/asset data. The Warp software allows the operator to place 'warp' points, re-aligning the pre/post O.S. map background(s).

The 'warp' points are used to identify corresponding positions on the old (pre-pai) and new (post-pai) O.S. backgrouns map(s). (i.e. corner of buildings, edge os paths and roadways. By following this process - any plant/asset data, originally placed against the old (pre-pai) O.S. background map, will be automatically re-aligned to the new (post-pai) O.S. map background.

The main menu for the 'Warp' system is shown below:

The following operations are provided by the Warp system: Display of individual map, plant/asset data - Allowing the operator to turn 'on/off' each of the different map bases, plant/asset data Overview window - Allowing display of all plant/asset data for easy navigation around the map base Mark-up tool - allowing 're-aligned' areas to be 'marked' - so time is not wasted reviewing previously 'warped' area

The following steps are required to re-align existing plant/asset data: 1. Open the required O.S. map tile/area in Warp. 2. Navigate to a specific area of the background map where plant/asset data exists. 3. Place required 'warp' points - to re-align both pre/post O.S. background maps. 4. Accept 'warp' points to 'shift plant/asset data.

P r e P A I D a t a

The following image shows a specific area of O.S. background map - as displayed in the Warp system. The data shown in this image can be identified as follows: Red linework - old (pre-pai) O.S. background map Black Linework - new (post-pai) O.S. background map Blue linework - plant/asset data placed against the old (pre-pai) background map

The image shows a shift between the old (pre-pai) and new (post-pai) data - and how this 'shift' effects the existing plant/asset data.

P l a c e m e n t o f W a r p P o i n t s

To re-align the plant/asset data (blue linework) to the new (black linework) O.S. background map - the operator must place a number of 'warp' points. S t e p 1 - Place point against old (pre-pai) O.S. background map

To place a 'warp' point the operator has to identify a 'point/position' on the old (red linework) O.S. background map

S t e p 2 - Place point against new (post-pai) O.S. background map This same 'point/position' must then be identified on the new (black linework) O.S. background map.

S t e p 3 - Accept Warp Points When these matching 'points/positions' have been accepted - all previously placed 'warp' points are applied to the old/new O.S. background map(s) - shifting the existing plant/asset data.

P o s t P A I D a t a

As the operator places new 'Warp' points, these points will be applied automatically, allowing the operator to see the effect these points have on the old/new O.S. map background.

If the 'warp' points have been placed correctly - the O.S. map backgrounds should be re-aligned correctly. (as shown in the above image)

P o s t P A I C l e a n u p T o o l s

Other tools exist allowing the operator to manually check and 'tidy-up' any errors or 'minor' modifications that may be required to the data. The tools required to carry out these operations include:

Compare module - allowing pre/post O.S. map backgrounds and plant/assett data to be viewed 'side by side'

Edit tools - allow 'minor' changes to be made, rather than 're-warping' a complete O.S. map tile area. If, after any updates that have been made, the operator is still not happy - options exist that allow the whole area can be 're-warped'

R e q u i r m e n t s