GRASS Basics - Desktop GIS: Mapping the Planet with Open Source Tools - page 290

Figure C.4: GRASS start-up form
If you don't have a directory for storing your GRASS locations in, create
it before you start GRASS, or pop out to another shell and create it.
You can store locations in any directory, but it's best to establish a
structure for your data to keep it apart from other non-GRASS files and
directories on your system.
In Figure C.4 , we have entered the required information to get started.
Since the location doesn't exist yet, we have to provide some additional
information as we proceed. Hitting Esc + Enter tells us that the location
we specified ( world_lat_long ) doesn't exist and asks whether we want to
create it. It also shows a list of the current locations (empty in our
case) in the database in case we made a mistake and want to select an
existing one. To continue, press Enter or enter n and Enter to cancel
the process. Next GRASS tells us what we need before we can proceed
to create the location:
• The coordinate system for the database
• The zone for the UTM database and all the necessary parameters
for projections other than Latitude-Longitude; x,y; and UTM