Joined: 12 Feb 2004
|Posted: Tue May 02, 2006 3:07 pm Post subject:
Hopefully this gets to you before you make your choice. I don't know anything about GPS's. The last navigational device I used was a loran when I lived in Florida and used to take boats to the bahamas. So I asked my techie hiking geek mark to help out. This is what he said.
|Here are the relevant features to consider for GPS- Backcountry use.
1.) 12 channel receiver ( 12 satellites can be locked in at any moment)- works best
3 channel multiplexer-( cheaper, but has to switch between satellites constantly) works great on boats, or in rural, flat areas, but DOES NOT work in the mountains- because it does not lock its signal.
2.) Number of Waypoints available(try to find 500 min.)- these are your points to mark a trail, on site or from a map, computer etc.
3.) Maps built in? Can they be loaded? Computer interface- to upload way points into maps or database on your computer? Map software included?these are all great features, but you pay for them with size, weight, and price-
4.)Selective Availability- the Gov't method for scrambling troop positions- ~1995 SA was about 120 ft now its closer to 25 ft. some units tell you the variance.
5.) Track back feature- the unit will synthesize Waypoints to lead you back to where you started-
Personally I love my Garmin, and it is unbelielably accurate- best use (go to topozone .com pull up a map, set the coordinates to UTM, put your cursor over a peak,pass, campsite, etc. input the UTM coodinates into a waypoint in the unit, then go out and use the GOTO feature to track distance, estimate time of arrival etc.
And he is looking into particular units you are looking at now.