Chapter 13: Position and Navigation
Orienting The Map
To orient a map means to determine how directions on the map align to directions on the ground.
This is one of the easiest way to orient a map. You don’t need to know which way north is. Nor
do you need any special tools. Two conditions must be met. First, you must be able to see one or
more linear features or prominent objects in your vicinity. Second, you must be able to identify
these same features on the map.
One linear feature, two linear features, and prominent features.
To use this method, first be sure you have a compass and a map that shows the direction of
magnetic north with a declination diagram. Then do;
First, find the magnetic north indicator on the map. This is usually a barbshaped arrow placed
in the margin.
Second, holding the map under the compass, turn the map until the compass needle lines up with
magnetic north on the map.
Finding your Ground Position
Once your map is oriented you can then figure out where you are on the map.
The most common way to determine your ground position is distance estimation in which you
use your distance and direction to other objects to location your position on the map. There is
two useful methods;
Inspection method: With this method, you find ground features on a map you’ve oriented and
then estimate their distance from you. To use this method, first orient your map and select a
feature on the ground that you can also identify on the map. Next, estimate the distance from
your ground position to the distant feature, and convert this estimated distance to map distance
using the map scale.
Compass method: You plot lines that intersect at your position. You don’t need to orient your
map before finding your position. Use your compass to look at a distant feature and note the
reading. This is the azimuth. Using this, you can figure out the back azimuth. Now draw a line
from the object on the map along the back azimuth. You can use one of the inspection method to
find your ground position to that feature and then convert the numbers.