The SDTS filter imports uniform lattices from several two-dimensional elevation grid file formats.
There are two separate types of SDTS DDF files. The Topological Vector Profile SDTS files contain boundary information. The Raster Profile SDTS files contain gridded elevation information.
The Spatial Data Transfer Standard, or SDTS, is a robust way of transferring earth-referenced spatial data between dissimilar computer systems with the potential for no information loss. It is a transfer standard that embraces the philosophy of self-contained transfers, i.e. spatial data, attribute, georeferencing, data quality report, data dictionary, and other supporting metadata all included in the transfer.
File Name Extensions
SDTS DEM .DDF, .TAR, .TAR.GZ, .ZIP, or .TGZ
Voxler can read the information in the various files directly from the compressed file. You do not need to unzip the compressed file.
If you do unzip the .TAR.GZ, .TAR, .ZIP, or .TGZ file containing the DDF files, there is an option in WinZip (or other unzipping software) that needs to be disabled. Use the WinZip settings to disable this option. All .DDF files must be extracted into the same directory.
In WinZip, use the Options | Configuration command to open the Configuration dialog.
Click on the Miscellaneous tab.
In the Other category, uncheck TAR file smart CR/LF conversion.
Click the OK button.
The Tar.GZ file will now properly unzip the files.
Format(s) Supported for Import
2D uniform lattice; 8-, 16-, 32-bit integer, float, double
Choose the File | Import command.
Specify import options in the Lattice Import Options dialog.
SDTS data sets can contain elevation data or several other types of data that are not applicable to Voxler. If you attempt to import an SDTS data set that does not contain elevation data, an error message displays.
USGS DEM .DEM Files
GTOPO-30 .HDR Files
DTED .DT0, .DT1, .DT2 Files
File Format Chart