Feature Spotlight, VentusAR

Feature Spotlight: Custom Terrain Services

DTMAs part of a license for VentusAR, users have access to our national coverage terrain services. The Ordnance Survey provides the DTM data for terrain services in the UK under the Open Data license. Currently these include OS Terrain 50 and Panorama.

However, when assessing a wind project, you may want to use a more detailed DTM to provide a better surface model. VentusAR customers have always been able to utilise a pre-loaded custom terrain data.  With VentusAR v2.1 we have added self-service functionality to the portal to allow user to import and manage their own a custom terrain services. As part of this additions, we have revised the pricing model for hosting custom terrain services.

This post explains the process of importing a custom terrain service in the VentusAR portal and the new billing model.

Creating a Terrain Service

The custom terrain service importing works as follows:

  • Use the portal to create and import custom terrain data
  • The following information will need to be provided:
  • Table name – a unique name for this terrain service. We suggest using a combination of company name, project name and DTM name (e.g. LN_TestProject_Terrain5). Validation will warn you if the table name is not valid
  • Data file – We support ‘asc’ or ‘xyz’ files. These can be compressed into a zip archive to reduce transfer time to the portal
  • Grid size – the distance between each point in the DTM. (e.g. Terrain 50 has data points ever 50m, so has a grid size of 50).
  • MinX, MinY, MaxX, MaxY – the minimum X and Y values covered by this DTM
  • X Offset, Y Offset – any offset from 0 this DTM uses. If the data is 0 aligned leave as 0, if the data is specified at mid-tile positions add the offset (e.g. Terrain 50 uses 25m offsets)
  • Coordinate system – the coordinate system the DTM should be loaded in (default is OSGB)
  • Creating and importing the terrain service can take up to an hour depending on load through the VentusAR portal at the time


  • The size of the custom DTM is measured in data points. Users can import a total of 1,000,000 datapoints arranged in a 1000×1000 point square. For a 50m DTM this allows you to import an area of 50km by 50km

Using a Terrain Service

To use a custom terrain service in a project:

  • Expand the Custom Terrain Services section on the Edit Project page
  • Select the custom terrain service to use

Please note that a custom terrain service can only be used on one project. Once it has been used, it will no longer be available to be added to any other project.


Billing for custom terrain data will be done on the first of the month for the previous month, i.e. billing in arrears. You will be charged a flat fee for each calendar month (or part of) that you have custom terrain data hosted in the VentusAR portal. A billing report can be found from the Terrain Services section of the portal. This shows the months that the terrain service has been active on the portal and the price.


Terrain services can be cancelled at any time (though they are billed by calendar month). They can be cancelled from the list of terrain services in the portal.