TOID
Encyclopedia
A TOID is a unique reference identifier assigned by the Ordnance Survey
to identify every feature in Great Britain
. The identifier consists of two parts, a prefix ‘osgb’ and a unique identifier that is 13-16 digits long. In GML
, a TOID is encoded as a gml:fid (Feature Identifier).
Around 440 million man-made and natural features have been thus identified: building
s, road
s, fields, phone boxes, pillar box
es, landmark
s and many other types. The identification system is designed to be used in GIS
, digital cartography
and in any customized computer application, including non-cartographic ones, where information about fixed, real-world features needs to be managed. Using consistent identifiers (IDs) makes it much easier to share data between various kinds of applications and systems. A TOID remains constant throughout the lifetime of the real-world feature it identifies, and is guaranteed not to be reassigned to anything else when the feature no longer exists.
Example: the TOID for the Tower of London
is osgb1000006032892.
, Ordnance Survey's master database, depends on TOIDs. Every feature is identified by a TOID in MasterMap. Other attributes of the feature are defined by relating them, via GML
, to the TOID. Users of OS MasterMap relate their own data to TOIDs of items of interest to them. Unlike with a custom designed GIS, one organization can share data with another organization easily since TOIDs are maintained centrally by Ordnance Survey, and are free to reuse.
, are defined in terms of multiple TOIDs: one for the main building, several others for the platforms, and another for the pedestrian bridge over the tracks. Users can create their own "supertoid" that unites them into one entity. This also acknowledges that defining the boundaries of vaguely defined folk objects is subjective: should the station car-park be defined as part of the station, for example? The TOID scheme leaves such decisions to its users, that is, those building information systems for end-users.
: a core part of its vision of a Digital National Framework.
"TOID" is a registered trademark of Ordnance Survey.
Ordnance Survey
Ordnance Survey , an executive agency and non-ministerial government department of the Government of the United Kingdom, is the national mapping agency for Great Britain, producing maps of Great Britain , and one of the world's largest producers of maps.The name reflects its creation together with...
to identify every feature in Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
. The identifier consists of two parts, a prefix ‘osgb’ and a unique identifier that is 13-16 digits long. In GML
Geography Markup Language
The Geography Markup Language is the XML grammar defined by the Open Geospatial Consortium to express geographical features. GML serves as a modeling language for geographic systems as well as an open interchange format for geographic transactions on the Internet...
, a TOID is encoded as a gml:fid (Feature Identifier).
Around 440 million man-made and natural features have been thus identified: building
Building
In architecture, construction, engineering, real estate development and technology the word building may refer to one of the following:...
s, road
Road
A road is a thoroughfare, route, or way on land between two places, which typically has been paved or otherwise improved to allow travel by some conveyance, including a horse, cart, or motor vehicle. Roads consist of one, or sometimes two, roadways each with one or more lanes and also any...
s, fields, phone boxes, pillar box
Pillar box
A pillar box is a free-standing post box. They are found in the United Kingdom and in most former nations of the British Empire, members of the Commonwealth of Nations and British overseas territories, such as the Republic of Ireland, Australia, India and Gibraltar...
es, landmark
Landmark
This is a list of landmarks around the world.Landmarks may be split into two categories - natural phenomena and man-made features, like buildings, bridges, statues, public squares and so forth...
s and many other types. The identification system is designed to be used in GIS
Geographic Information System
A geographic information system, geographical information science, or geospatial information studies is a system designed to capture, store, manipulate, analyze, manage, and present all types of geographically referenced data...
, digital cartography
Cartography
Cartography is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively.The fundamental problems of traditional cartography are to:*Set the map's...
and in any customized computer application, including non-cartographic ones, where information about fixed, real-world features needs to be managed. Using consistent identifiers (IDs) makes it much easier to share data between various kinds of applications and systems. A TOID remains constant throughout the lifetime of the real-world feature it identifies, and is guaranteed not to be reassigned to anything else when the feature no longer exists.
Example: the TOID for the Tower of London
Tower of London
Her Majesty's Royal Palace and Fortress, more commonly known as the Tower of London, is a historic castle on the north bank of the River Thames in central London, England. It lies within the London Borough of Tower Hamlets, separated from the eastern edge of the City of London by the open space...
is osgb1000006032892.
TOIDs in OS MasterMap
OS MasterMapOS MasterMap
OS MasterMap® is Ordnance Survey's flagship digital product, launched in November 2001. It is a database that records every fixed feature of Great Britain larger than a few metres in one continuous digital map. Every feature is given a unique TOID , a simple identifier that includes no semantic...
, Ordnance Survey's master database, depends on TOIDs. Every feature is identified by a TOID in MasterMap. Other attributes of the feature are defined by relating them, via GML
Geography Markup Language
The Geography Markup Language is the XML grammar defined by the Open Geospatial Consortium to express geographical features. GML serves as a modeling language for geographic systems as well as an open interchange format for geographic transactions on the Internet...
, to the TOID. Users of OS MasterMap relate their own data to TOIDs of items of interest to them. Unlike with a custom designed GIS, one organization can share data with another organization easily since TOIDs are maintained centrally by Ordnance Survey, and are free to reuse.
TOID revision history
If the data for a feature is edited, for example to reflect a real-life change or to correct an error, then the changes are referenced by TOID. Unless the feature has undergone drastic change, the feature keeps its original TOID, enabling one to track changes to a feature over time if one has access to the historic data.Granularity of TOIDs
Every object in OS MasterMap has its own TOID, including polygons, lines, points, symbols, text and addresses. Complex entities such as Southampton Central railway stationSouthampton Central railway station
Southampton Central railway station is a main line railway station serving the city of Southampton in Hampshire, southern England. It is on the Wessex Main Line, the South Western Main Line and the West Coastway Line...
, are defined in terms of multiple TOIDs: one for the main building, several others for the platforms, and another for the pedestrian bridge over the tracks. Users can create their own "supertoid" that unites them into one entity. This also acknowledges that defining the boundaries of vaguely defined folk objects is subjective: should the station car-park be defined as part of the station, for example? The TOID scheme leaves such decisions to its users, that is, those building information systems for end-users.
Intellectual Property
In keeping with recent Open Data initiatives, Ordnance Survey has stated its policy on royalty free use of the TOID with the aim of allowing easier integration of data using its spatial databaseSpatial Database
A spatial database is a database that is optimized to store and query data that is related to objects in space, including points, lines and polygons. While typical databases can understand various numeric and character types of data, additional functionality needs to be added for databases to...
: a core part of its vision of a Digital National Framework.
"TOID" is a registered trademark of Ordnance Survey.