Unique Geographic Identifier (UGI)

As we move towards base registers for public information, Unique Geographic Identifier (UGI's) provide the key to integration of datasets for geographic and statistical analysis. With over 50 million objects assigned a Unique Geographic Identifier, Tailte Éireann - Surveying is providing the trusted identifiers needed to build the foundations of modern information exchange through semantic web and linked data.

Within The National Map data model, all objects have a Unique Geographic Identifier (UGI) and data relating to that object is maintained during the complete object life cycle. For example, each building, land parcel, section of road, section of path, or section of river has its own unique Identifier against which additional information or attribution can be stored and managed within a digital mapping database. The Identifier is never changed, nor is it re-used for new objects.

When any new object is created, the system generates a UGI that is unique to that building and that persists throughout the lifetime of the building. If the building subsequently undergoes a change, such as a change of use or a change of geometry (where, perhaps, the building is extended), the building object maintains its identity through the UGI.

Only if the building ceases to exist would the object and the UGI be removed from the live database. All objects have a mandatory UGI property. In the database, each UGI is composed of a 32-character alphanumeric string.

  • UGI is a Trusted Identifier from a PS perspective for geographic objects
  • UGI is NOT a geographic locator such as Eircode although geometry and location data are associated with each UGI
  • UGI will always have other attributes – geometry, form, function, status etc.
  • Designed for machine reading as opposed to human reading
  • Recognised at UN level as a template for future trends in GS industries
  • Ireland seen as a frontrunner in UGI development
  • UGIs are seen as part of the first high value national base registers