OS Open Data

From the UK OS... Create and support innovative, exciting ideas and applications using Ordnance Survey mapping. With OS OpenData you can access a selection of the most detailed mapping datasets available for Great Britain. See details here
also... If you have an idea that uses OS OpenData, why not enter the GeoVation Challenge for a chance to win a slice of £25 000 to make your idea a reality

OS Open Data

LIDAR height data portal (UK)

The Environment Agency's Geomatics Group, a leader in high quality LIDAR survey and remote sensing data capture, has launched a new web-based portal, allowing customers to access and purchase highly accurate elevation data online, from the group's extensive archive of LIDAR data.

Captured over a period of 12 years, Geomatics Group holds the largest collection of high resolution LIDAR data for England & Wales. Currently, with over 65% (98,225 sq km) already mapped, at a range of spatial resolutions ranging from 25cm to 2m, the archive is constantly being updated, with new areas surveyed and existing areas re-flown to gather higher resolution data. The database includes many major urban areas, as well as rural flood plains and coastal zones. See more info or jump to www.geomatics-group.co.uk/GeoCMS/Order.aspx

LIDAR height data portal (UK)