Thread: Gps
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Old 12-12-2009, 02:09 PM
paulp575 paulp575 is offline
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Join Date: Jan 2009
Location: Spokane, WA
Posts: 69
Default Gps

Quote:
Originally Posted by Ceg_ View Post
Tell me what is a good GPS for off road trails that doesn't cost a lot. I am looking for one I can down load where we drove and over lay on a topographic map.
Most GPS topographic maps suck; too little detail for the small viewing window.

Having said that, I purchased the Garmin eTrex Venture HC. It was around $150.00+tax from Walmart. While Garmin uses proprietary maps ("MapSource"), their maps aren't too bad.

Unfortunately most topographic maps are seriously out of date.

The reason I bought this on is because it was their new line of HC GPS units. That means, according to their website at that time, they have better sensitivity. Supposedly they will pick up satellites under dense foilage, in canyons (not too sure about that one!) plus some other features. It has a colored screen and is considered a basic handheld for the trail.

In spite of Garmin's use of proprietary maps, I found a website that gives steps on building your own background maps:
http://home.roadrunner.com/~creek/garmin.htm

I have not tried the steps listed on that website, but from what I know about GPS units and mapping software, it seems doable.

If you are concerned about your GPS being capatible with your DNR software, forget it - probably. From my experience, most governement agencies use ArcGIS - a $1,500 piece of software! It has a very steep learning curve.

As long as you can convert your GPS waypoints to a GPX file, you should be OK.

When I was on an expedition scouting out a trail for the Idaho Panhandle National Forest folks NE of Mullan ID, I made some waypoints and a track. I downloaded them to my computer and put them over a topographic map background (got the USGS topoquads from GeoCommunity), it matched up pretty well. but, the 4WD trail wasn't close to what the GPS showed. When I overlaid it with Google Earth, it lined up perfectly! Although you could not see the entire trail, the switchbacks were visible in Google Earth and the track overlaid exactly!!!

There are some less expensive programs you can use for overlaying info you download from a GPS. The one I use the most is GlobalMapper. It costs $299 per license and is very easy to use.

If you are looking for free downloadable topoguads, digital elevation models and digital orthoimagery (satellite images), you can get them in various places on the internet. Being here in Spokane, I have been able to locate those for all of the state of WA as well as Idaho.
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Spokane WA
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Member of:
Washington Off Highway Vehicle Alliance (WOHVA http://www.wohva.org)
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