OS NGD Geographical Names
A Lightning Talk
What are the layers in OS NGD Geographical Names?
There are currently 3 features in the Named Feature Collection
A settlement, locality, geographical feature, or area of water that has a name, represented as a polygon.
What formats does the OS NGD Geographical Names data come in?
The OS NGD Geographical Names data comes in two formats, CSV and GeoPackage (GPKG)
The GeoPackage format comes ready to load into the GIS package of the users choice with different gpkg files for each layer.
The CSV format is more suited for loading into a database. It has all of the same layers in csv format and all the same attribution as the GeoPackage, however instead of storing the geometry in a GIS-ready format, it is stored as a POINT and POLYGON attributes (for ‘Named Point’ and ‘Named Area’ respectively), with all of the vertices stored as co-ordinate pairs in the text file.
Named Point
These features are point representations of named places. These include various settlements ranging from cities to hamlets, natural areas such as mountains, hills, valleys, and estuaries, and other named urban localities such as suburbs and railway depots.
This has some correspondence to the OS Open Names dataset, except it is more restricted in the place types included
Post codes and roads are excluded
Other place types such as education institutions do not feature
There are many new named places included in the OS NGD dataset which did not feature in OS Open Names, especially small neighbourhoods such as Larkbeare and Wessex Estate in Exeter
Named Area
The same set of features as Named Point, but with their geographical extent represented as polygons.
This is a new dataset. OS Open Names does not provide polygon geographies
Named places range from very small patches of land to vast geographies such as the North Sea, the Moray Firth, and the Western Highlands
The options for the attribute Descritpion Group:
Named Road Junction
A named intersection between roads at a junction or roundabout. The intersection may be numbered, have an official name or be assigned a modeled name based on the names of the intersecting roads.
A road junction that is part of a road classified as A Road that has an official number.
OS Emergency Services Gazetteer Junction compared with OS NGD Named Road Junction
Geometry: Motorway Junctions and Roundabouts are a single point geometry in OS Emergency Services Gazetteer and Multipoint geometry in Named Junction
Schema: OS Emergency Services Gazetteer is in an AddressBase Premium format and Named Junctions have an OS NGD schema
Attribution: OS Emergency Services Gazetteerhas an AREA_NAME. There is no AREA_NAME on the Named Junction feature
Classification: OS Emergency Services Gazetteerhas a classification scheme and Named Junction has a description
More information on OS Emergency Services Gazetteer can be found in the OS ESG Lightning Talk
How is the data derived?
The Named Area polygon geometries have been defined in two ways, indicated by the Extent Definition attribute
Manually Defined Complete are where polygons have been manually drawn from other OS data, satellite imagery, and (in the case of settlements) historical OS records. These are drawn to best represent the real-word extent (as opposed to official or administrative definitions).
Auto-Generated Indication are those which have been not yet been manually drawn (see images, right). These are typically one of the following.
Hills, which have been approximated as round regular polygons, as their true definition is ambiguous.
Bodies of water automatically identified from OS MasterMap Topography Layer.
For other types of feature, a convex hull containing the name label(s) as they appear in OS MasterMap Topography Layers.
Links that may be useful:
This content has been developed from what was originally a Lightning Talk PowerPoint slide set. These slides are available to PSGA members to view and download from the PSGA members area of the OS website
Last updated
