Land-Form Panorama from DIGIMAP

[from EDINA's description of Land-form PANORAMA data:
"http://edina.ac.uk/digimap/description/products/panorama.shtml"]

Land-Form PANORAMA is a digital representation of the contours from
Ordnance Survey's 1:50 000 scale Landranger maps. Contours are at 10
metre vertical intervals together with breaklines, lakes, coastline
and a selection of spot heights to the nearest metre. Digital contour
accuracy values are typically better than 3 metres root mean square
error.

The Ordnance Survey has used the dataset to derive mathematically a
digital terrain-model (DTM) dataset. The dataset consists of a grid of
height values at 50 metre intervals interpolated from the contour
data. Height values are rounded to the nearest metre. Accuracy varies
according to the complexity of the terrain, from 2 metres in a hilly
rural area to 3 metres in an urban lowland area. This data is only
available for downloading to your machine.

DTM data can be used for terrain analysis of lines of sight and in
applications such as visual impact studies, drainage analysis, site
planning.