Have a query on shapefile. I have a shapefile containing a number of polygon features representing buildings. I am trying to extract the elevation of the building. I would like to know if the usual convention in denoting the shapefile elevation is given with respect to the sea level or is it given with respect to the ground?
1 Answer
For the HEIGHT it would be with respect to ground.
For the ELEVATION, most countries have a national geodetic survey that should be used as a reference. Those NGS are usually defining their own MSL.
What you usually extract from an existing dataset is the elevation. The height can then be computed as the difference between elevation at the top and the (minimum) ground elevation around the building. (Note that, for firemen, the height is computed to the latest floor, not to the roof)
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Hi, so can I say that actual building height is ELEVATION -surveyed ground height (extracted from DEM/DTM)? Jul 10, 2014 at 0:43