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I have a number of LIDAR files (the extension is .adf). When put together, they show the same area (each shows one part of it), so, before I do anything else with them, I would like to combine them into one.

In other words, the equivalent of the Append operation on vector data. What's the best way to go about this in ArcGIS 10?

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Thank you! This has answered the question, at least for now! – Mhoram Mar 25 '12 at 22:30
then it should be marked answered – Brad Nesom Mar 26 '12 at 13:08
@Dr. A.D.Prasad, please describe a little bit about the link that you have posted. – Farid Cher Sep 3 '15 at 20:38

NED isn't strictly LiDAR data, it's a conglomerate of many different elevation sources to produce a seamless elevation coverage. That said, are you able to view the rasters directly in ArcMap/ArcCatalog? .adf files are part of the ESRI GRID format and should work like any other raster in ArcGIS.

If you cannot view the files in ArcGIS then there is something else going on, such as corrupted files. See this thread for more info. If nothing else you can always try downloading in a different format such as GeoTIFF.

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I can view the files if I simply add them to ArcMap individually. It is when I try to mosaic them that the problem arises. – Mhoram Mar 27 '12 at 17:15
Where can I download USGS LIDAR data in GeoTIFF format? This didn't seem to be an option on the USGS Seamless web site. – Mhoram Mar 27 '12 at 17:17
You are correct, it looks like GeoTIFF is only available by emailing them. See their FAQ: – blah238 Mar 28 '12 at 2:01
If .adf files are part of the ESRI GRID format, does this mean that I can use ArcGIS tools on them directly, without converting them to any other format? – Mhoram Apr 1 '12 at 2:58
I think I figured out what was wrong with adding rasters to the mosaic dataset. Apparently the workspaces with the NED tiles needed to be in the same folder as the geodatabase with the mosaic dataset and the toolbox with the model. In that case, it worked. Otherwise, the rasters were full of nothing but NoData values. – Mhoram Apr 2 '12 at 0:10

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