knobbytracks said:I agree. Depending on the intended use, the larger units offer optional
maping software that is really nice when hiking (topo) or vacationing
(services). I believe they'll do most anything the auto based units
will do except it fits in your hand and you can map the results on a
PC.
Kevin
The handheld units like the Garmin Vista do not do turn by turn
navigation like the automobile units. They cannot calculate what roads
to take to get from address A to address B. The know nothing of street
addresses.
For outdoor use there are basically two types of GPS units: mapping and
non-mapping. The mapping units can load in topo maps or street maps so
you'll be able to see features around your current location. The
non-mapping units cannot load in maps. All you'll see is a blank
screen around your current location. No roads or other landmarks to
give you a clue as to where you are.
The mapping units require additional software maps to load on the GPS
receiver. Those additional maps cost additional money. So after you
buy the GPS unit you also have to buy the software maps if you want to
make use of the mapping features.
The non-mapping units show just a blank screen around your current
location. They will display waypoints that you can program in during
your trip or before your trip. They will also display routes which
link different waypoints together. The ones that offer tracks will
display a breadcrumb trail of where you have been. It's like putting
dots and straight lines on a blank sheet of paper. The dots are
waypoints and the straight lines are routes. The GPS can tell you what
direction and how far you need to go to get to a specific waypoint
(like back to the car). That's the basic navigation you get from those
kinds of units. It's the kind of navigation you get with the
Forerunner 205 and 305. The Forerunner 205 and 305 can connect to a PC
or Mac and load your track to MotionBased.com so you can see your route
on the computer with streets and other landmarks.
The mapping units have the same features of the non-mapping units
except they also display a nice map on the GPS screen.
--
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