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You can take a heading with a GPS


DENelson83
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Yes, your sensorless GPSr, such as an eTrex H or GPSMAP 76, can give you the direction you're facing while you're not moving.

 

You get a clear view of the sky and a relatively accurate fix, and then just take the part of your GPS that contains its internal antenna, aim it towards the sky, and then suddenly jerk the unit forward a considerable length, such as ten centimetres. The heading field on your GPSr's screen will then give you the direction in which you jerked the antenna forward, accurate to within about fifteen degrees. This technique is called "casting a heading," because you manipulate the GPS like you would with a fishing pole when you cast it.

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...jerk the unit forward a considerable length, such as ten centimetres.
Why not arm's length? Make sure you have a lanyard for extra security ;)
...accurate to within about fifteen degrees...
I'll keep this in mind for when I don't know what time it is and can't see the sun or moon. Edited by lee_rimar
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Do you have any references you can site on this or is this your own finding?

 

Sounds like a good idea, but it is effectively giving the gps two data points to work with. If during those instantaneous moments the gps was correcting itself, getting a better (or worse) reading, I think 15 degrees would be an understatement.

 

Scenario 1. Geocaching close to home. Process works and everyone's happy.

Scenario 2. Lost in the woods. GPS battery low. Want to shoot a bearing to find a reliable landmark to get home. Off by up to 25 feet per hundred feet. Big error, could be a lot worse. Nobody with any sense would end up in this scenario unless they placed too much reliance on the gps.

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This is based on my own experience. And remember, I said you get a clear view of the sky first, naturally implying "out in the open", not "in a thick forest", unless you had a high-sensitivity receiver.

...accurate to within about fifteen degrees...
I'll keep this in mind for when I don't know what time it is and can't see the sun or moon.

How can you not know what time it is with a GPS? :ph34r:

 

Would the batteries have to be dead?

Edited by DENelson83
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