SDTS GIS format. Geographic information standard used by the U.S. Geological Survey. Used for archiving and exchanging terrain data. SDTS is an acronym for Spatial Data Transfer Standard. Based on ISO 8211. U.S. Federal Information Processing Standard. An SDTS transfer archive consists of multiple .ddf files, typically combined in a .tar.gz file. The file extension .ddf is derived from Data Descriptive File. Binary format. Contains digital elevation models (DEM). Digital elevation models are stored as a raster of elevation values.
Import is fully compatible with the SDTSDEM file format.
Import can also read "SDTS" digital line graph files.