Figure 5-30.--Origin of azimuth circle.
Figure 5-32.--Detour around enemy positions or obstacles.
the back azimuth is the forward azimuth minus 180°.
For example, if the forward azimuth of a line is 112°
(fig. 5-31), the back azimuth is as follows:
112° + 180° = 292°
When the forward azimuth of a line is 310°, the back
azimuth is as follows:
310° - 180° = 130°
Figure 5-32 shows an example of how to bypass
enemy positions or obstacles by detouring around them.
This allows you to stay oriented by moving at right
Figure 5-31.--Azimuth and back azimuth.
angles for specified distances. For example, if you are
moving on an azimuth of 360° and wish to bypass an
the center of the azimuth circle (fig. 5-30). Azimuths
obstacle or position, you change direction to 90° and
take their name from the base line from which they have
travel for 100 yards; change direction back to 360° and
been measured; true azimuths from true north, magnetic
travel for 100 yards; change direction to 270° and travel
azimuths from magnetic north, and grid azimuths from
for 100 yards; then change direction to 360°; and you
grid north (fig. 5-21). Therefore, any one given direction
are back on your original azimuth
can be expressed in three different ways: a grid azimuth,
Bypassing an unexpected obstacle at night is a fairly
when measured on a military map; a magnetic azimuth,
simple matter. To make a 90° turn to the right, hold the
when measured by a compass; or a true azimuth, when
compass as described earlier in the method for night use;
measured from a meridian of longitude.
The BACK AZIMUTH of a line is its forward
turn until the center of the luminous letter E is under the
azimuth plus 180°; or if this sum is greater than 360°,
luminous line (do NOT change the setting of the
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