I'm currently working on a project wherein I am trying to assess the feasibility of creating a DSM from a DEM by adding building footprints to it (LiDAR manipulation is something I'd like to avoid for now). I have a DEM in ESRI Grid format, and another ESRI Grid raster that I created from a building footprint polygon shapefile (set the z-value to 20m for all buildings, then used Polygon to Raster conversion). Both rasters have the same projection and cell size. I would like to take the 20m values for the buildings, and add them on top of the elevation values present in the DEM (vs. simply replacing them). I will be using the resulting DSM for flow path modeling, so I need a continuous raster surface.
I thought to use Raster Calculator to combine the two, but I'm unsure if I am using the correct syntax. Simply trying to add DEM + Footprint Raster didn't work, and doesn't even create a new raster.
This was my syntax
"BldFootClp" + "CityDEMClip"