- Home
-
Public Sector
Public Sector
Quick links to popular content
- Business
-
Leisure
Leisure
OS getamap – print your route
Have your map custom made
Visit our shop
Read our magazine
-
Education & Research
Education & Research
Schools
Further & Higher Education
Research
General interest
-
About us
About us
Quick links
- Support
OS Terrain - frequently asked questions
Q) What is OS Terrain?
OS Terrain is the name given to Ordnance Survey’s new range of height products, These are three-dimensional models of the bare earth surface known as Digital Terrain Models (DTMs). The range will consist of two products:
1) OS Terrain 5™
A mid-resolution DTM product, designed to be interoperable with our large-scale data
2) OS Terrain 50®
p>A lower-resolution DTM product, designed for landscape visualisation and analysis over large areas.The grid is now available through OS OpenData™.
Q) Are these products an update of Land-Form PANORAMA®?
No, OS Terrain products originate from a completely new capture flowline designed to use imagery flown for our large-scale products to produce height data for a new height content store. The store has been designed as the base for our 3D strategy to enable the height data to be used throughout our portfolio and for new products in the future.
Q) Is there any third party content, e.g. lidar?
No, the source data was captured by Ordnance Survey Integrated Capture Programme suppliers and is wholly Ordnance Survey intellectual property.
Q) Will there be contour data?
OS Terrain 50 is published in both grid and contour formats. Both data types are created from the same source data and are supplied as tiles. Currently only the grid data product is available to download.
Here are some details on the two formats:
- OS Terrain 50 grid - a grid of heighted points with regular 50m post spacing
- OS Terrain 50 contours - a contour dataset of 10m standard contour polygon features, which includes, mean high and low water boundaries and spot heights.
Q) Why is the grid available as GML if this cannot be translated?
Ordnance Survey is committed to open data formats and seeks to comply with INSPIRE. GML is a complex language which provides additional functionality in a non-vendor-specific format.
The OS Terrain .gml file effectively provides metadata (such as location, grid spacing and the vertical reference system). It also contains spatial reference information in a software independent form. The data itself is provided as an ‘external data block’, that is, the ASCII file. Currently, common software packages do not support GML in this form but the ASCII grid data can be used alone.