Jaryetz

Hello folks, I've recently decided to do some exploration of local State Forests, and as such I figured a GPS unit would be rather helpful.

Before I got myself lost in the woods, I decided to give it some testing using landmarks I know, and I have a bit of a problem.

When I set waypoints, the arrow will point directly to them when I am traveling east/west, but if I'm traveling any N/S at all, the arrow does not point at the waypoint. If I walk directly toward the waypoint (despite the arrow) it appears to move diagonally until I reach the waypoint.

The GPS coordinates and the waypoints appear to be very accurate, but if I follow the arrow to get to the waypoints I'd end up traveling in a semicircle before I actually got to it.

And to put it into perspective, at about 100 yrds, if I followed the arrow in a straight line, I'd be off by about 40ft...fairly considerable.

If anyone can give me any clue why this thing doesn't point toward the waypoints I've set, I'd greatly appreciate it.

Oh, and the compass seems to be relatively accurate, though little unsteady.

I've never had a GPS so I don't know how critical I should be, but the waypoint thing has been fairly discouraging thus far.

Thanks!

HumVee

Jaryetz, I'll have to do some testing with my GPSMAP 76CSx - but I've never noticed it behaving differently on different bearings. 40 feet deviation from your marked waypoint isn't all that bad, depending on obstructions in the area (even trees affect satellite receiver reception). The good news is that regardless of whether you're travelling 100 yards or a 100 miles, you'd still only be dealing with 40 feet of deviation at each waypoint. As you stand in one place, I'm sure the unit continues to try to refine positional data to help you narrow down the deviation and get you closer to your target. You should see a circle that shows projected deviation, and that circle should tighten as the GPS unit refines its calculations.

I haven't used the eTrex Summit HC, but I'm sure it's not all that much different from my 76CSx in basic function. Have you enabled WAAS (Wide Area Augmentation System)? It's in Setup Menu > System Setup > WAAS/EGNOS. Refer to your Owner's Manual for more details (but not much more - GPS manuals are notoriously light on info). If you have it enabled, and the unit is able to receive the correction data, it should significantly increase positional accuracy. As for the digital compass in these older units, you must hold the GPS unit perfectly level when utilizing the compass feature, just as if it was a magnetic needle in an analog compass. Newer handhelds (like some of Garmin's Oregon's and the Dakota 20) incorporate the new 3-axis digital compass capabilities, that don't care how you hold your GPS. That's a nice feature I'll be looking forward to add to when I purchase my next handheld. BTW...I had no idea what EGNOS is, and had to look it up. European Geographic Overlay Service is the European version of WAAS for North America.

I'll post again after I've had a chance to play with my 76CSx outdoors....

Jaryetz

Heres a little MSPaint of the problem I'm having. I think this better explains it than I can.

And to fully explain how I'm testing there, there is a stretch of straight road at my house that ends at a stopsign. I'm marking the stopsign as a waypoint, going to the other end of the road, and then pointing the GPS at the stopsign.

I've tested this way at several different spots, and they all read this way.

Attached Thumbnails

 

HumVee

Jaryetz, is your map orientation set to "North Up" instead of "Track Up"? That what it sounds like to me. I'm still at work, but will try to test your scenario when I get home. To check what your Map Orientation is set to:

1. Go to your Map screen
2. Press Menu to see your Menu options
3. Scroll down to Setup Map and press Enter
4. Scroll left-right until the icon with the cardinal points (compass points) is selected
5. Scroll down to Orientation and select Track Up if you want the map to rotate so the direction you're travelling is always "up"
6. Press Quit to get back to your map

Jaryetz

Its already set to Track Up, the arrow always points toward the top of the screen, and in the top left corner of the screen is a little "N" indicator arrow.

I've tried with both Map Up and Track Up and either way the arrow that represents me doesn't point toward the waypoint.

Am I right in assuming the arrow should be pointing toward a waypoint if I'm looking at it? I've done a lot of searching and can't find anything remotely like this issue. Perhaps I got a bad unit?