Global Mapper on your computer. Don’t have it? You can purchase it here.
1. Launch Global Mapper.
2. Import .TXT as a layer.
3. Select the Import Type as Elevation Grid. Be sure to specify the order that the coordinates are in, and identify if the coordinate pairs have a name or ID at the start of the line. The default parameters for Elevation Grid are good. Hit OK.
4. Select the correct projected coordinate system that the file is in when prompted.
5. Right click on the layer that was created (it is called "Elevation grid" by default) and export it as a GeoTIFF by navigating to Layer > EXPORT - Export Layer(s) to New File..., selecting GeoTIFF, and clicking OK.
7. Follow the prompts and ensure that the output file type is a 32 bit signed float (near the top of the options window). Click OK.
8. You're done! The resulting file should be a DEM in the format we require that can then be uploaded for processing like any other terrain.
I still can't do it!
We wrote these articles to arm you with everything you need to get the job done on your own, but we understand that sometimes this isn't sufficient. If you're stuck, you can connect with our support team by clicking the support button on the top right corner of your user portal.