How to expand the raster's extents and add null value into the expansion part?

Question

I have run a hydraulic model and I got a result of depth raster of the sediment (the brown one). I want to sum the sediment raster with the topography raster (the black one) so I will have the elevation of riverbed after the sediment depth is applied.

My goal is to have a cross-profile of the river after the sediment depth is applied onto the initial riverbed elevation. I used to use Stack Profile tool, and use the help of a line shapefile to sign the location of cross-profile. The problem is that the sediment raster's extent is not large enough to cope with the topography raster so when I created a cross-profile of them, both raster did not align correctly.

What steps should I take if I want to expand the sediment raster's extent and put null values in the expansion cells?

Do you have any idea of what I should do in order to get both cross profiles of sediment raster and topography raster on exact place (for example: the pink line)?

Answer 1

If it is an option. Recreate the Sediment raster, but pre-define the processing extent in your tools' (or model) environment as your DEM extent. This sould expand the extent of your output, and overlay its cells to match those of the DEM. However if your Hydrualic model isn't based on arcgis-desktop, you might want to resampling it, using the resample tool. You might want to define processing extent to the extent of your dem as well. Note that resampling alter your data, i.e. of your sediment raster.

Answer 2

I finally found how to do it! My actual problem is that the sediment raster contains "NoData" values so the Stack Profile tool can not read the values. So I simply sum topography raster with sediment raster using Raster Calculator with applying Con(IsNull) function to sediment raster => Con(Isnull("sediment raster"), 0 , "sediment raster").