Input is the height file from the step SLANT2H. Output are two files containing the latitude (phi) and longitude (lambda) corresponding to the height file.
These files can be further processed with programs cpxfiddle, proj, and GMT to create a DEM in a regular grid in any projection desired (UTM for example). See the bin directory and the shell scripts there for examples how to do this. Likely, for each specific application, these scripts are best copied and adapted to your needs. The interpolated matrices from GMT are in grd format that can be handled by Matlab, etc.