We have received 2 DEMs for a project; one covers our entire county and has 6ft pixel resolution. The other only covers a major city, has irregular boundaries, and is 3ft pixel resolution. Since the 3ft DEM has irregular boundaries, there are areas of NoData within the DEM extents.
I have a few questions below since I don't work with rasters that often:
Any help would be greatly appreciated!
You will have to resample the 6' dem to 3' or generalize the 3' to 6' if you want to have them together.
In either case, you can put them together by using the Con tool
Is this any different than having ortho-imagery that is 2 different pixel resolutions? Shouldn't we be able to use a mosaic dataset to load in raster datasets (imagery or DEM or whatever) and be able to order the rasters to display? I didn't think the varying pixel resolutions would matter with a mosaic dataset.
I suppose I understand if you plan on using the Con tool where the pixel resolutions would need to be the same since you're basically saying: if True, use this value; if False use this value...but for display/management I would think using a mosaic dataset should be a simple solution, no?
Sorry Matthew, I didn't see mosaic data set as your desired output, I just saw mosaic which would require Con since two would become 1
Matthew
I only have a moment to reply so will have to be brief - and might leave out some details - but this is doable (I originally wrote "relatively simple" but that's a matter of perspective ).
For MUCH more detail see http://esriurl.com/ImageManagement, follow link to the Image Management Guidebook and look for the chapter on Elevation.
I presume you've seen our raster functions for generating Hillshade, Slope, Aspect etc. on-the-fly from the MD? Don't create separate rasters for those derived products unless there's a compelling reason...
Last note - most clients are okay with an obvious boundary at the edge of the 3 foot data, so users are aware if they're working at the edge of 2 datasets (perhaps with 2 different accuracy specs). If you want to blend that edge so it is NOT obvious, that is doable, but definitely gets into more details...