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36

This map (and the Wikipedia article) will explain why you don't have a problem (in the UK, I'm guessing), but others do, elsewhere. In the UK, you can ignore it at the moment, but you need to understand WHY you're ignoring it :) As an aside, compare this with the declination in 1872... Then, the declination error in the UK would have been between 20 and ...


23

This depends highly on your location. Contrary to popular belief, the difference between the magnetic pole and the geographic pole is not the only reason for declination. As a matter of fact, the magnetic poles are simply defined as the points where the magnetic field points vertically. This is not the same as the pole of a anyway non-existing earth-magnet. ...


21

Where your magnetic compass points can be quite far away from the north shown on your map For example, on the line marked 30, your compass would point 30 degrees away from true north.


14

They're absolutely NOT the same thing. The distance varies. But it's about 500 miles. (http://www.livescience.com/41955-north-pole.html) Since its discovery in 1831, the magnetic North Pole has been around Canada’s Ellesmere Island, about 500 miles (800 kilometers) from the geographic North Pole. https://en.wikipedia.org/wiki/True_north


14

Magnetic pole The distance from the rotational north pole varies over time -source By the time you read this, the north magnetic pole could be half the circumference of the planet away from the true (i.e. rotational) north pole. Thats over 20,000 km apart. It has been in the past. See magnetic pole reversal and rate of transition. Declination More ...


13

The distance between the magnetic north and geographic north poles is not important for navigation purposes. What matters is the angle between them, which is called the magnetic variation or magnetic declination. The magnetic variation varies depending on where you are on earth, and also changes slightly from year to year. In Pittsburgh, Pennsylvania, ...


11

There are several ways to determine true north, especially when you have a map and compass: Competent maps, like most intended for backcountry hiking, will have the magnetic declination marked. This is usually in one of the corners. Take a look at any USGS topo map, for example. The compass will tell you the direction to magnetic north, and the map tells ...


10

Olin Lathrop's very good answer to the question you reference basically already contains most of the information needed also your gut feeling about the topic is quite right. So let's look at it in a bit more general way: Keeping your compass declination in mind gets the more important, the closer you are to one of the magnetic poles, the more you travel ...


8

What you describe is exactly how it was done: Accurate measurement of distances and angles Obviously, measuring distances on flat ground is relatively straightforward: you use a known length measurement (perhaps a robe marked at known intervals); and to measure the distance to a distant point, use two points and a bit of geometry (Pythagoras is helpful ...


7

While Rory Alsop's answer points exactly to the method followed by cartographers and geologists before the invention of GPS and other modern techniques, I'd like to make a point that it was done with an assumption that they knew what altitude they are at and when you stand at planar location located from a mountain at a known distance and you can figure out ...


6

As others have said the importance depends on your location. In the UK & Europe the correction is quite small, approx 2-3 degrees and can therefore mostly be ignored. Compared to parts of the US where the correction can be at least 15 degrees. This is because the magnetic north pole lies somewhere in northern Canada, so the UK is relatively far away for ...


6

The topics of navigation and cartography are two sides of the same coin, and there are entire books written about each. It is interesting to study the history of cartography because it very graphically shows the corresponding improvements in navigation over time. In order to make an accurate map, you need to know first where you are making your ...


5

Not discounting the existing answers which provide great perspectives. You don't really care where the North Pole is. It is not like there is only one or two, nor is like anything is stable. There are half a dozen north poles and most of them move around regularly and they move a lot (10s and 100s even 1,000s of miles/kilometers). Wandering of the ...


2

We could get really complicated with this. But basically, magnetic north is a mostly fixed place on the surface of the earth. It's actually moving, but very slowly. Sometimes the map you have may have two compass circles on it. One inside the other. The inner circle identifies magnetic north, and the outer circle identified true north. In addition, the map ...


2

At night it is very easy to find true north using the stars (true south doesn't quite have an equivalent.) First identify Ursa Major, the Great Bear or Big Dipper. Then take the two stars at the end of it away from the handle, and follow the line they make for 5 times its length. The star you hit is Polaris. Head towards it and you are heading towards true ...


2

You need to do some research on the area that you are traveling on. Google maps or the NOAA maps using seaclearII.exe will allow you the ability to make a map guide, that you can annotate as you travel. mark off 100 yard and point to point track measurments. If you are going to dead recon from point to point on a river as an exercise or recreation you might ...


2

As the other answers point out using trigonometry you can determine the height of a distant peak. You can also use the same approach horizontally to determine the distance between two points. Provided that the length of one side of a triangle is known the other two sides can be calculated. Using a combination of these techniques any area can be divided into ...


1

One of the primary techniques is the use of Dead Reckoning although the secrets of long distance Polynesian maritime navigation still remain a mystery despite huge evidence of their wayfinding ability. The easiest way for maritime navigators to map locations was to build on the predecessors knowledge through the use of the Periplus. It served the same ...


1

In the UK the prevailing wind blows from the south west and trees/ bushes grow away from the wind so assuming one can see a tree it should be easy to determine the other points of the compass. Elsewhere in the world it would be sensible to determine the direction of the prevailing wind prior to setting out.



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