Most of the smaller GPS units run from = batteries.  You can buy all sorts of accessories for them that = will allow them to run from 12v power.

I have a (~$200 USD) Garmin GPS II+ that I am quite = pleased with.  It takes a while to master the use of a GPS (and I = have to brush up each spring), but extremely handy. 

I have the following GPS related accessories:
1. Handlebar mount for my mountain bike
2. Dash mount that uses Velcro in the Vanagon
3. Combination 12v auto power cord and serial = adapter cable for PC
4. Adapter cable for my Palm V (made it myself from = plans on the web)

What do I use my GPS for?:

1. The coolest use is the "Moving Map" = feature that was alluded to yesterday.  I run Delorme Topo! USA = maps on my laptop which receives input via the serial connection to the = GPS on the dashboard of the car.  As I drive, the GPS will display = heading, altitude,  and speed, and the laptop display (on the = passenger seat) displays my exact location on a 15' topographic = map.  Very handy when traveling criss-crossing networks of logging = roads!

2.  Another use is marking and storing a route = while backcountry tromping.  I'll go off road on either my bike or = the Syncro, and after returning, open the fridge, pop a beer, and fold = out the laptop.  I upload the route to the laptop and overlay it = onto a topo map, noting any detail points with little flags and notes = (i.e. "great view", "spring", or "abandoned = mine").  Then I save the maps and can refer back to them = later.  In fact, if I want to retrace an earlier trip, I can load = the waypoints into the GPS and hit the trail.  The GPS will guide = me back to the spot or spots using the same route that was originally = taken.

3. Finding trail heads that are listed on a = map.  Sometimes trails on a 15-year old USGS map can be pretty = hard to find in "real life".  I note the lat/long of the = spot and punch it into the GPS, then use the GPS to find the = spot.  I can also pull up the map on the Topo! USA CD and mark the = waypoint on the laptop, then upload the waypoint to the GPS.

4.  Nautical navigation.  This is the = easiest and best use for a GPS, since there are no "surface = features" to deal with.  You can always travel in a straight = line to get somewhere (unless there is a freighter in your path!) and a = GPS comes in very handy for marking and finding fishing spots, diving = spots, and secluded coves out at the islands (the Channel Islands off = Santa Barbara)

I don't find the GPS to be particularly accurate at = determining speed or altitude.  It is more of a moving average = than an actual reading.  The problem is that #1 you have to be = moving for the GPS to take a reading, and #2 any changes in course can = introduce errors and distortion since the GPS bases all the = calculations on straight lines between points.  (i.e. speed is = determined by time to travel from point A to point B; if you don't = steer a straight course, the calculation will be off.)

If anyone has any other neat ideas, or questions = about GPS's in general, let me know!

Brent Christensen
'89 GL Syncro Westy
Santa Barbara, CA

> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.C= OM]On Behalf
> Of Andrew Grebneff
> Sent: Thursday, May 11, 2000 3:31 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: GPS
>
>
> The GPS units people are fitting in cars: do = these run off
> the car's power,
> or are they battery-operated? I'd find one = useful both in the
> van (speedo)
> and out (locating geological localities). Maybe = I need one of each.
>
> Andrew
>