- What is Terrain 2?
Terrain 2 is a joint Ordnance Survey (OS) and Environment Agency (EA) Digital Terrain Model (DTM) – with national coverage to a two-metre resolution.
- What is the coverage of Terrain 2?
For Scotland, content consists of Ordnance Survey-derived Digital Terrain Model (DTM) only. The content for England and Wales consists of data from both Ordnance Survey (OS) and Environment Agency (EA). EA Lidar DTM data for Wales contains data owned by Natural Resources Wales.
- How is this data supplied and what do I need to use it?
Terrain 2 is published in two grid formats: ASCII and GeoTIFF. Both data types are created from the same source data and are supplied as 5km² tiles. You'll need geographic information system (GIS) software to use OS Terrain 2.
- Where is the GML schema file?
Terrain 2 application schemas are available on our xml page.
- How will steps be minimised between datasets?
The merged area between the two datasets will consist of a 100m overlap. Within this overlap area a feathering process will be applied to minimise the potential impact of ‘steps’ caused by data captured at different times and at varying degrees of accuracy.
- How is the accuracy of the product measured?
Terrain 2 RMSE (root mean squared error) is derived from comparing multiple height values against known observed points from surveyed ground measurements. Please refer to the Terrain 2 user guide (PDF) for further information regarding accuracy statements for OS and EA source DTM data.
- What is RMSE?
RMSE - or Root Mean Square Error - is a statistical measure of accuracy that compares the likely error between two datasets comparing a predicted value and an observed value.
All RMSE (z) results are represented using a confidence level of 95%. This is the level of certainty with which you will estimate the true population value.
Confidence levels state the probability that the value of a parameter falls within a specified range of values. A 95% confidence interval is a range of values that you can be 95% certain contains the true mean value of the population.
- What will be the frequency of update for Terrain 2?
The update frequency will be dependent on customer feedback.
- Where can I find metadata for Terrain 2?
Metadata such as latest flying date exists for each polygon of OS and EA data within a single tile of data. Find metadata in our Terrain 2 coverage metadata file (CSV).
- What licence do I need to evaluate Terrain 2?
If you are an OS Partner, you will need to accept two of our licences in OS Orders - our Developer Contract licence and our Data Exploration Licence (DEL).
We’ve done this to enable Partners to access the data quicker for the six-week evaluation period.
We're trialling this beta product for six weeks to get your feedback.
You can download data from our Terrain 2 product page.
If you're an existing customer, you can log in to OS Orders to download the data. By downloading the data, you agree to being contacted by OS for feedback.