topic Re: Merging DEMS in ArcGIS Spatial Analyst Questions

Merging DEMS

aaronboci1 — Tue, 12 Nov 2013 22:21:25 GMT

I have 6 DEMs, all of which are the same resolution, projection and coordinate systems. I would just like to make them into 1 DEM so that I can mask them to an AOI I am working in. I looked up the help button and it showed me the tool and how to get to it. I have spatial analyst extension on. it says go to customize<toolbars<production something. Either way, I click on customize and toolbars and this next thing I am supposed to click is not an option. Is there a way to get it to appear or is there another way to merge these DEMs. I am planning on doing slope, hydro, ARCSWat, and adding multiple layers into this and joining them later as well as disaggregating the resolution from 10 to 1. I know the assumptions that will have to be made but that's what my stakeholder wants.

Re: Merging DEMS

TimBarnes — Wed, 13 Nov 2013 01:23:24 GMT

Just use the following tool in ArcToolbox: 'Mosaic to new raster' in Data Management Tools > Raster > Raster Dataset

Re: Merging DEMS

curtvprice — Wed, 13 Nov 2013 23:01:25 GMT

Just use the following tool in ArcToolbox: 'Mosaic to new raster' in Data Management Tools > Raster > Raster Dataset

In the spirit of teaching a man to fish:

Desktop help: A quick tour of finding tools
http://resources.arcgis.com/en/help/main/10.2/index.html#//002400000001000000

A little wrinkle here, if the raster cells do not exactly line up there will be some resampling. The way to make sure this happens correctly is to set the raster environments for Snap Raster (a raster to "line up with") and Resampling Method ("BILINEAR") before you run Mosaic To New Raster. (I think this setting requires 10.1 or later. In 10.0 you need to run the Resample tool, on each raster first, described below.)

The tool you will want to use to sample down to a smaller cell size is the Resample tool, probably with BILINEAR again (this is an argument for that tool, not just the environment). As this raster will be really large, I'd do your Mosaic operation first, make sure everything is the way you need it to be, then run the Resample.