Would someone be able to give me the stepped process showing how to add building/woodland elevations to an existing DTM raster in ArcMap?
I seek this in order to prepare a surface model for a viewshed analysis.
I have run a viewshed analysis on a series of points using a DTM raster derived from UK OS Terrain 5. This creates the bare-earth model and is working well.
I now need to overlay this with buildings (at 8m) and woodlands (at 15m) from UK OS Open Map Local, and then add this elevation data to my existing Terrain 5 DTM. This is the bit I'm struggling with:
- Adding the elevation data to the UK OS Open Map shapefiles for buildings and woodland. The method to do this would be to add an extra field in the attributes table and assign the 8m/15m elevation to this field. What field type/properties should the new field have?
- Converting the shape file to a raster dataset using the Polygon to Raster tool on each raster created.
- Merging with the existing Terrain 5 DTM using the Raster Calculator tool. How do you assign the cells with no trees/buildings a value of '0'?
I've seen the question answered for QGIS but not ArcGIS Desktop.