importing DEM, Landsat data

I will importing both DEM and Landsat data into Grass soon, but based
on what I know so far, I see a problem. That is, the commands I have
know about (m.dem.extract, i.tape.tm) assume the data is coming from tape.
The data I have and will be getting are already on disk/diskette.
The LandSat diskette, for example, has separate disk files for each of the
bands and a separate header file as well. Are these files in need of
processing to convert to Grass raster format, or are they already in that
format? How do i proceed to import such files into a Grass database?

The DEM files are USGS dems and exist as indivual ascii files. Again, the
m.dem.extract assumes it's reading a tpe not a disk file. How to proceed?

Thanks in advance,

Gurcharan S. Khanna
Quantitative Anthropology Lab
UC Berkeley
khanna@qal.berkeley.edu

PS my local source of grass information is out of town at the moment, else
   i would have gone there first :slight_smile: