True North and Magnetic Declination – a Trick to Endure

The essential principle of magnetic declination is to understand when we are navigating the wild on the map and the compass

Still complicated Do not forget, At least as traditionally taught, by adding / subtracting methods. When you think you understand it, the concept floats like fog in the morning light. There is a simple, practical approach to adjusting magnetic declination when locating bearings. The whole explanation begins with the term "northern".

2 north

Many people know that maps and compasses have a map of 2 north-east directions. Or the geographic north pole where all longitudinal lines meet The earth rotates around an imaginary axis passing through the northern and southern wands

The compass needle point in the magnetic north direction that the earth magnetic Magnetic North latitude travels about 5 miles per hour, currently creeping around the Canadian Hudson Bay somewhere NW, about 450 miles from the real north

Magnetic Declination

The Northern and Magnetic North Angular deviation in the aviation world is referred to as "declination" or "variation", but declination differs in different parts of the earth in the state of Washington, 20 ° east of the declining angle, meaning that the magnet lies to the east of 20 ° N north latitude. In Tennessee, the declination angle is 0 ° and Maine is 20 ° west.

Declination values ​​are found in margins or legends on topographic maps. As the magnetic north point moves continuously, it is important to find another topo map in the forest. Similar memory is that compasses have been calibrated in different parts of the world. So when you buy a compass, be sure to use it for large hiking holidays.

Follow these steps,

1. Place the compass on the map so that the base plate is pointing in the direction of the arrow.

2. Turn the compass dial so that the north direction of the compass is parallel to the north in the map.

3. Place your compass in your palm and turn yourself until the compass with the compass does not fit the north mark on the muzzle.

If you've gone 10 miles in the woods in Washington state, without having to go through the forest, That Actual declination value for bearings reaches more than 3 miles. That's too much!

To set the bearings to be turbid, keep in mind the central principle:

Creating a Map Holder = Magnetic Bearing

Adjusting the bearings to compensate for magnetic declination. There are two ways to consider magnetic declination to find the bearings: the adjustable compass and the non-adjustable compass

The simplest way to do this is with a controllable compass. Simply rotate the compass declination adjustment screw to the correct value and all readings will automatically turn north. If available, it is always best to set a compass during the walk.

The next best way of declination is to mark the declination value of the non-adjustable compass at the start of the trip.

Just do it. For example, if the map indicates a western 20 ° declination value, the compass will appear at 340 °. If the map indicates a 10 ° bend value, it indicates a 10 degree direction. Set the mark with a permanent marker and then remove the rubbing alcohol later.

Now, when you take your traps in the field, put your compass into your palm and rotate until the needle in the compass with the front speed dial is marked. Then the large arrow on the base plate points toward the bearing and automatically compensates for the magnetic declination


Source by Will Robertson

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