importing DEM, Landsat data

[Gurcharan Khanna]

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 at qal.berkeley.edu

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