We have now added Ordnance Survey’s most detailed terrain data to the Data Download section of Digimap. OS Terrain 5 is created from the same source as the Ordnance Survey’s aerial imagery, meaning that it is kept up-to-date and works very well with the OS MasterMap® data.
OS Terrain 5 Contours, as the name suggests, have a 5 metre interval and the Digital Terrain Model (DTM) is on a 5 metre grid. The OS Website states the data has a good accuracy, typically exceeding 2 metres RMSE (not more than 2 metres different from the real world) with particular emphasis on significant landscape features such as roads, railways, slopes, quarries and lakes.
From Digimap’s Data Download the you can take up to 400 5 by 5 km tiles of OS Terrain 5 in a single download. The contour data is available in Shapefile or GML format and the DTM data is available as in ASC (Ascii Grid) format.
This new dataset has been included in Digimap due to the new licence agreement (see the previous blog post for more details). The other datasets included in the new licence, Urban Paths, MasterMap Site layer and Points of Interest data should be added into the service in the new year.