How to combine multiple rasters that DO NOT overlap?

Question

I am trying to combine 3 DEM rasters that do not overlap. When I use the Mosaic to New Raster tool (using LAST as the mosaic operator), I am noticing that the new raster has incorrect values. The new raster does not show elevations of the original rasters that exist at those points. The values seem to be skewed slightly, and I am not sure what it is interpolating since there are no overlaps in datasets.

All rasters are on the same projected coordinate system, with the same number of bands (1) and the same cell size (5') which are all the same settings specified in the Mosaic to New Raster dialog window. Is there a better tool to combine rasters that do not overlap? So far the Mosaic to New Raster tool works well when there are overlaps.

danretired · Answer

arcmap... so long ago 😉

Mosaic To New Raster (Data Management)—ArcMap | Documentation (arcgis.com)

would be the one, with Last as the default and First for the colormap option

If there is no overlap, then there should be nodata values.

You will have to provide an example

Since Mosaic operators—ArcMap | Documentation (arcgis.com) only deals with overlaps treatment,

cp_0101 · Answer

Thank you for your reply. I am using ArcMap and it looks like the Merge tool only works for points, lines, and polygon features:

"Combines multiple input datasets into a single, new output dataset. This tool can combine point, line, or polygon feature classes or tables.

Use the Append tool to combine input datasets with an existing dataset."

danretired · Answer

If they don't overlap and are of the same data type

Merge—ArcGIS Pro | Documentation

make sure you set an extent that covers the combined areal extent