How to Do a Resection With a Map and Compass

Step-by-Step Guide

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   Step 1: Choose a distinctive

   Most maps will include a small diagram that tells you how much to subtract from the magnetic direction, in degrees.
   
   Magnetic north varies from true north because the earth's magnetic pole is not actually exactly beneath the north pole.
   
   Where you are located will make magnetic north vary according to your position relative to the Earth's magnetic pole. ,,, That's 180 degrees off from the map direction to the terrain feature.
   
   The reverse direction of a feature at 60 degrees would be 240 degrees. , You will be located somewhere along that line. ,, Your location is where the two lines intersect on the map.
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   Step 2: distant feature such as a hilltop or bend in a river.

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   Step 3: Use your compass to determine the exact magnetic direction from your location to the feature you chose.

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   Step 4: Convert from magnetic direction (based on true north) to map direction (based on magnetic north).

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   Step 5: Place the center point of your protractor on the map

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   Step 6: in the location of the feature you've chosen.

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   Step 7: Line up the 0-degree point of your protractor on a line running from map north to map south.

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   Step 8: Make a mark next to your protractor at the degrees of the "reverse direction" of what you calculated map direction.

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   Step 9: Draw a line using a straightedge along the line indicated by your work with the protractor.

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    Step 10: Repeat the process with a second landmark.

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    Step 11: Double-check your calculations

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    Step 12: adjusting the lines if necessary.

Detailed Guide

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