Topocad Digital Terrain Model File
Adtolla SE is a software developer which develops software used in GIS, Mapping and Surveying.
One of the programs that is used for Surveying and Mapping is Topocad, this is a package that is used for Computer Aided Design from the field survey stage up to the finished designs or maps.
Digital Terrain models that show tunnels make use of the .tdtm file extension in Topocad.
How to open .tdtm files?
Software to open .tdtm files
What are .tdtm files