OS NGD Land
A Lightning Talk
What layers are in OS NGD Land?
There are five feature types in the OS NGD Land theme. All of them have the same geometry as their equivalent features in OS MasterMap Topography Layer but all with new OS NGD attribution.
This is a set of polygons, the same as the Land theme in OS MasterMap Topography Layer, that cover classifications such as Arable or Grazing Land, Residential Garden, Made Surface, Bare earth or Grass, Mixed Trees.
What formats does the OS NGD data come in?
The OS NGD Land 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 POLYGON, POINT or LINESTRING attribute with all of the vertices stored as co-ordinate pairs in the text file.
What is new the attribution?
The attribution has changed from the OS Master Maps Topography Layer product, largely due to the differences in the intended use for the data.
All OS NGD data has the new OSID attribution
Features have TOIDS if they existed in the previous OS MasterMap family. In addition they have a version date, change type, change data and theme
OS NGD Land now has Land Use and Land Cover attribution as well as the source of the evidence
Land Cover and Land Use is categorised into an a/b hierarchy giving a broad category and then a specific group
Land also indicates the capture specification allowing the user to understand the RMSE (Root Mean Square Error) that the feature was captured at
Where has the new attribution come from?
Ordnance Survey surveyors and remote sensing teams have been capturing and maintaining information on land cover, land use and a more detailed level of description for over 10 years.
This data has then been transformed to match attribution for existing products, such as OS MasterMap Topography Layer
However, in the OS NGD data it is being published at the original, more granular level
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