Basic GTOPO30 GeoTif workflow

07-02-2017 01:43 PM
New Contributor

Hi, I am trying to create a DEM for Africa from scratch using the 2000 unfinished SRTM GTopo 30 ArcSec dataset.

I have downloaded four GeoTiffs containing the whole continent area, but I am finding very hard to properly clean and mosaic the 4 images together into one single file. Is there an standard workflow to make the downloaded GeoTifs ready to work in ArcMap?

One of the downloaded files can be found at 

I don't understand why I am unable to run any tool on the original tiff files. I generally get a 9999 Error message. Today I have been able to export the GeoTif to a GeoDBS but after that I am stuck.

The things that I would like to correct are:

a) Inconsistent Extent. I imagine because the projection is "incorrect". but I am failing to understand why. Projection seems to be set to GCS_WGS84, what is incorrect here and how do I fix it?

b) Ocean elevation is set to -9999. I imagine I can fix this with the Raster Calculator and the "SetNull" function. Is it worth it?

c) Is there anything else I should be aware of when working with this particular set of SRTM data?

I would appreciate any guidance on this. Thank you for your help.

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MVP Esteemed Contributor

Ensure the workspace path and filename doesn't contain any special character (except underscore "_"). Also don't save the input or output files in C:\Users folder.

Disable Background Processing (Geoprocessing > Geoprocessing Options > Uncheck Background Processing). Foreground and background processing—Help | ArcGIS Desktop 

Let us know if the issue still persists.

Think Location
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