Signals in the deep woods.

[MN12]

Hey everyone!

 

I've nailed a few caches and have found something I think is very interesting.

 

Why is it that when I'm in the woods and standing still (Very important). Why does the direction arrow on my GPS start to do the Mexican Hat dance and jump and point me in all different directions?

 

Thanks

 

MN12

[+Desert_Warrior]

your GPS cannnot see a good steady movement, so it tries to show you what it can. Wether it is a broken signal through the trees moving in the breeze, or a very slight movement in you, it tries to report what it thinks is happenning.

 

That's my story and I'm sticking to it.

 

Mike. Desert_Warrior (aka KD9KC).

El Paso, Texas.

 

Citizens of this land may own guns. Not to threaten their neighbors, but to ensure themselves of liberty and freedom.

 

They are not assault weapons anymore... they are HOMELAND DEFENSE WEAPONS!

[+Criminal]

Even though you're standing still, the unit is constantly adjusting and readjusting your position. Every time the position adjusts, the unit interprets this as movement and tries to point you towards the waypoint you told it you wanted to find.

 

EDIT: you may notice it more in areas of poor or intermittent reception. The more the reference signals change in strength and view, the more the unit will try to correct your position.

 

http://fp1.centurytel.net/Criminal_Page/

[Lyra]

If your unit has an averaging feature, there's usually some "lag" between signal reception and actual display of the data. Most units update once per second, and the data it's trying to process may change drastically in the interval between updates.

 

Always wear proper caching safety equipment!

[+cdobis]

...proper caching safety equipment?

[+Poindexter]

The averaging function is for averaging the position of a waypoint you have entered. The lat/lon of the waypoint is the average position of all the fixes taken over the time period that you are in the averaging mode. This increases the accuracy of the waypoint. Other than that, your position is simply the latest fix that is taken each second, and causes your direction arrow to hunt around for reasons others have stated.

[+Dersu]

You did not say what GPSr you are using, so I will talk about one that I have.

Some GPSr have a pinning function that will lock

your position until you move a short distance. My Eagle Expedition II has it and it is really useful. I don't need it as badly now that Selective Availablity (SA) has been turned OFF by the goverment, but it stills helps when I use my old 5 pounder Eagle.

If you have this function, try it with it off and then try it with it on, maybe it will help.

With the pinning function turned ON, your position

will be locked when you stop moving

 

I have flouted the wild, I have followed its lure, fearless. familar, alone; yet the wild must win,

and a day will come when I shall be overthrown. By: Robert Service

[+writer]

Aside from the other answers, it's important to remember that a GPSr is not the same thing as a compass, although some have one built in. There is a difference between knowing your location (a spot on the globe) and your orientation (which way you face). The GPSr does the former, and then depends on your movement and matehmatics to figure out the latter by tracing your movement. That is one big reason to carry a compass with you.