WEBINAR: OS Product Managers Carol Hanks and Daniel Bream discuss the potential product, what you can do with it and answer a number of questions from the live audience.
What's a DSM?
A DSM is a measure of the surface of the earth that includes all terrain features visible on the earth surface. This data set represents a three-dimensional model of the earth’s surface at the time of capture. This includes all permanent and non-permanent features, such as the ground surface, bare earth, rocks, man-made structures, vegetation; and transitory features such as vehicles and animals.
How is the data being created?
DSM data is collected as part of our integrated revision capture process. It's derived from automated photogrammetric processes from the same source data used to update our imagery, topography, and digital terrain model data sets.
What's the data supply format?
OS DSM sample data is provided at 1m resolution in GeoTiff format and includes three different geographic areas, each covering an area of 5km2. Files are approximately 98mb in size, uncompressed:
- Manchester, Lower Left co-ordinate 380000,395000
- Kidderminster, West Midlands, Lower Left co-ordinate 380000,273000
- Lytchett Maltravers, Dorset, Lower Left co-ordinate 390000,094000
We have also provided data of Manchester as 1 km2 tiles.
How accurate is the data?
Estimated planimetric accuracy (x,y): 1.1m rmse
Estimated height accuracy (above ODN) (z): 1.5m rmse
1m resolution Digital Surface Model 3D visualisation of Manchester city centre with blue to red height colour ramp
Digital Surface Model viewshed analysis – greens represent visible areas to fixed 1km distance when viewed from central location
Digital Surface Model profile analysis – cross-sectional profile of DSM