You can use the USGS SDTS Digital Elevation Model files in Surfer in any place a grid file is required.
Surfer does not require you to unzip the files from the SDTS.TAR.GZ file first. You can:
- Simply select a command that prompts you for a grid file (e.g. Home | New Map | Contour).
- In the Open Grid dialog, change the Files of type to DDF SDTS DEM.
- Select the SDTS.TAR.GZ file and click Open.
In Surfer 10 and previous, it was necessary to unzip the data first to your hard drive to use it in Surfer.
- Unzip the data using a program like WinZip or similar
- Note: If you are using WinZip, click Options | Configuration, click the Miscellaneous tab and in the Other category, un-check 'TAR file smart CR/LF conversion' in order to properly unzip the files.
- When you unzip the file (for example, 3809474.DEM.SDTS.TAR), there will be many [.DDF] files that are contained in the SDTS transfer. All these files must be together in the same folder.
- In Surfer, select a command that prompts you for a grid file (ie. Map | New | Contour Map).
- In the Open Grid dialog, select any one of the DDF files and click Open.
Updated February 13, 2017