Using raster calculator to replace the values of one raster with values from another

[TarickAbu-Aly]

I have two raster datasets. The first raster is a very large DEM of a river network at 15.625 ft spacing. The large DEM was generated by resampling roughly 3,000 smaller rasters from a 3.125 ft cellsize to a 15.625 ft cellsize, then mosaicing them all together to form the final merged raster dataset.

The issue here is that a critical part of the dataset is the elevation of the levee tops in the system which were degraded slightly in the resampling operation. I have a 3D polyline of the levee centerline alignments that I have sampled elevations from the raw 3.125 ft rasters and converted the vertices to points. Then I converted those points to a 15.625 cellsize raster. The second raster dataset is a breakline of sorts. It would obviously be preferable to use the polyline as a breakline and generate a terrain from the points. However, I do not have the point shapefiles that the raster DEM's were generated from.

What I would like to do is somehow use the raster calculator to replace the values of the first DEM with the values of the second DEM of the levee tops, where the two rasters overlap. Is this possible or is there some other work around for my problem. Any suggestions would be appreciated.

Thanks!

[TarickAbu-Aly · Accepted solution]

I have found a solution... It was a two step process. First I set the spatial analyst extents to be the same as the larger DEM raster. Then, I created a conditional statement in the raster calculator to only save the cells from the second raster that were greater than the first. Then I used the mosaic to new raster tool to replace the cells in the DEM raster with the levee top raster cells that were higher than the existing DEM.