Using GPS with utm grid coordinates

cvsetter

FNG
Joined
Oct 2, 2016
Messages
68
Location
central pa
This will be my first trip west this sept. And I've been reading up on backcountry navigation.i like the idea of the utm grids to plot where you are on the map from your GPS.i understand how to plot and read them,I get pairing the map datums on topo and Gps.what north heading do you use?do I set to true north and adjust the magnetic declination on my compass to the area or after more reading do I set it to grid north and adjust the difference of magnetic declination to grid north on the compass for navigating to a way point.
 

corylee4870

Lil-Rokslider
Joined
Jan 7, 2016
Messages
157
My understanding is to set your declination to Grid North that matches your map. Then set your GPS to Grid.

If the gps doesn’t have the Grid option, use True north & set your declination to True north.

I’m still new at this so I would verify what I’m telling you.

Back Country Navigation 1
Back Country Navigation 2

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Rokwiia

WKR
Joined
Nov 12, 2016
Messages
886
Location
In the mountains
Before I go out in the woods, I draw magnetic north lines on my topo maps. You can do it using the computer if you pint out maps or with a 24" rules and a pencil. I do both. This provides you with several SIGNIFICANT advantages.

1) In the field, you can take a reading on the fly without having to orient the map. Sometimes there are high winds or heavy rain which make orienting a map cumbersome if not impractical.

2) In the field, you won't be using the magnetic needle to take readings so there is no concern about metal nearby altering a reading.

3) In a survival situation, where you may be suffering from hypothermia, you may not be thinking correctly. Declination calculations and knowing when to add and when to subtract, can become confused. Make a mistake and it could be a fatal one. I'm a SAR member and have seen the havoc hypothermia can wreak on one's ability to think clearly. The more you can put things on autopilot the better.

This method removes your need to correctly align a magnetic needle and calculate declination adjustments.

4) By taking your time and drawing magnetic lines on your map (digitally or by hand), you get the opportunity to study and visualize the area you will be hunting or hiking. You'll know in advance what to expect. It will quickly help you develop your terrain associations skills. Those who are masters at wilderness navigation can do so with only a map. No compass needed. They mentally convert the 2D map they're looking at into 3D imagery and compare it to they're looking at in the field.
 
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ramont

Lil-Rokslider
Joined
Nov 19, 2017
Messages
259
Location
Montana
Other than being in the military, I have never had to regularly navigate via map and compass in the field in any precise way, I take estimated traveling azimuths and adjust as I go along. But I always take a topo map with me and refer to it as I go along my track, it helps me keep oriented as I'm traveling so that my chance of getting lost is far less. I also use a GPS regularly. Between the two I've never had a problem with knowing where I was or where I needed to go.

That being said, if I am in really dense forest then yes, I'd do a more precise job of navigating and I'd check my map and compass far more often but when that happens I've never needed the precision of having a perfectly oriented map. I would usually lay the map on the ground and the compass on top of it, adjust for the grid to magnetic north declination by turning the compass away from the grid north lines slightly, identify an imaginary line to my target, move the compass close to that imaginary line and estimate my traveling azimuth. That's good enough for general navigation but it wont be very accurate if you are trying to find your way back to your truck or a downed elk. On the other hand, since I've always got a GPS (with extra batteries and a back GPS too), I just mark a way point and navigate to the spot.
 
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