Alchemy is an application created in-house for addressing the specific issue of client asset data mapping and problems introduced by the PAI program. The process is divided into 3 main stages.
Additional link creation
The OS supply link files which contain lines linking the original position of features in the pre-PAI OS Base data, to the same feature on the post-PAI base data (OS MasterMap). Our application has the advantage that it creates additional links to the Ordnance Survey supplied links. This is a major advantage, particularly for utility companies where the user data is not always snapped to the OS base data. For utility companies, quite often the features are buried and therefore the spatial relationship to base data is more important than snapping.
It should be noted that it is not always necessary to create additional links however there are many cases where the additional links are found to enhance the accuracy of the final output.
Automatic Shifting
Our application uses complex rubber-sheeting algorithms to shift the user data using the link files.This is an automatic process, for which different options can be selected depending on whether the user data is snapped to OS data.
This process produces an 'error check log' which indicates possible areas where user intervention is required.
Manual Correction / shifting
As no process will ever be 100 % automatic, the data is then passed on to a data operator who checks the output together with the 'error log file' and manually corrects any problems. Usually the operator can make an informed decision on how to shift the data based on the results of the data audit and the initial study report, however when the answer is not immediately obvious he will raise a query to the client through our internally developed Query Management System.
