May 19, 2009 -- Aerial survey company Bluesky has launched two online height models covering the whole of England, Wales and large parts of Scotland. With accuracies up to 25cm in urban areas the Digital Terrain Model (DTM) and Digital Elevation Model (DEM) provide detailed representations of the topographical variations in the surface of the earth including, in the case of the DEM, vegetation cover and man-made structures. Visitors to www.bluesky-world.com can search the online models using a place name, postcode or geographical coordinate before viewing their chosen area or downloading digital files.

Available online, in a range of formats suitable for use in Geographical Information System (GIS), Computer Aided Design (CAD) or 3D visualisation software the DTM / DSM data is designed for applications that require a real world representation of the earth’s surface and the vegetation and buildings that cover it. From simple identification of ground surface features to more complex projects including flood risk assessment and mobile network planning, the data is offered free of Crown Copyright with flexible licencing terms.

Digital Terrain and Elevation Models are photogrammetrically derived using specialist software to measure common points in overlapping aerial images. The online models provide height measurements at 2 and 5 metre resolutions, for the DEM and DTM respectively, with positional accuracies of up to 1 metre. Enhancement using LiDAR (Light Detection and Ranging) data in urban areas enables accuracies of up to 25 centimetres to be achieved.

“The height models are derived from GeoPerspectives aerial imagery using specialist software by a dedicated production team,” commented Rachel Tidmarsh, Managing Director of Bluesky. “As this imagery offers the most up-to-date view of our world so the DTM and DEM data in turn provide the most current, detailed and accurate representation of terrain and surface of the earth for a wide range of applications.”

GeoPerspectives is a joint venture between Bluesky and Infoterra providing national coverage of orthorectified aerial photography, digital terrain & surface models (DTM/DSM) for 3D modelling, and colour infrared imagery (CIR) for vegetation analysis.

Website: www.bluesky-world.com
Contact Bluesky sales on +44 (0)1530 518 518