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Conditions:
Given a standard 1:50,000-scale military map
with two known points plotted on the map, a
protractor, a straightedge, a pencil, and
requirement to determine the azimuth from
your location (point A) to another point
(point B) on the map.
Standards:
Determined the grid azimuth (in mils or
degrees) from your location (point A) to
point B to within 1 degree or 20 mils.
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Performance Steps
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1.
The direction from one point to
another, either on the map or on the
ground, is called an azimuth. Azimuths
are given in degrees or mils in a
clockwise direction from north, and
all azimuths taken from a map are grid
azimuths.
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a.
An azimuth in degrees can be
any number up to 360, as there are 360
degrees in a circle. Due east is 90
degrees, due south is 180 degrees, due
west is 270 degrees, and due north is
360 degrees or 0 degrees.
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b.
An azimuth in mils can be any
number up to 6400, as there are 6400
mils in circle. Due east is 1600 mils,
due south is 3200 mils, due west is
4800 mils, and due north is 6400 mils
or 0 mils.
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2.
The most accurate way to
determine an azimuth from a map is to
use a protractor. There are two types
of protractors in use in the Army
today.
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a.
The square protractor (GTA
05-02-012), which has a degree scale
and a mil scale. The inner scale is
the degree scale, and the outer scale
is the mil scale.
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b.
The semicircular protractor,
which may or may not have two scales:
an outer scale in mils and an inner
scale in degrees. The mil and degree
scales consist of two rows of numbers.
In each of the scales, the outer row
of numbers is used when determining
azimuths to the east of your position,
and the inner row of numbers is used
when determining azimuths to the west
of your position.
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3.
Use the protractor properly.
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a.
Plot the location of two points
on the map.
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b.
Using a straightedge, draw a
straight line (azimuth line) from
point A to point B.
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Note. The line
drawn between the two points must be
long enough to cross the scale(s) of
the protractor in order to read the
azimuth. Should the line between the
two points be too short to cross the
scale(s), extend the line beyond point
B until it crosses the scale(s).
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c.
Place the index of the
protractor at the point where the
azimuths line crosses one of the
vertical (north-south) grid lines.
This procedure allows greater accuracy
in aligning the index line to a true
reading where the azimuth line crosses
the protractor scale.
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Note. Ensure that the 0-degrees or 0-mils mark on the
protractor is toward the top (north)
of the map.
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d.
Start at the 0-degree or 0-mil
mark on the protractor and read to the
right (clockwise) until you reach the
point where the azimuth line crosses
the scale(s) of the protractor.
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Note. When using the protractor, each tick mark on the degree
scale is 1 degree, while each tick
mark on the mil scale is 20 mils.
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e.
Read the azimuth where the
azimuth line crosses the scale(s).
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(1)
Figure 49, 65 degrees.
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(2)
Figure 50, 65 degrees - 1150
mils.
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Note.
When using the square protractor, the
scale can be read all the way around
the protractor. In using the
semicircular protractor, when point B
is to the left (west) of point A. The
protractor must be reversed so that 0
is toward the bottom of the map
(south).
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Evaluation
Preparation:
Setup:
Provide the soldier with a 1:50,000-scale
military map, two points plotted and labeled
(A) and (B), a protractor, a straightedge,
and a pencil.
Brief
Soldier: Tell the soldier to determine
the azimuth from point A to point B within
one degree or 20 mils.
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Performance Measures
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GO
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NO
GO
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1.
Determined the correct azimuth
(within 1 degree or 20 mils).
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Evaluation
Guidance:
Score the soldier GO if the
performance measure is passed. Score the
soldier NO GO if the performance measure is
failed. If the soldier scores NO GO, show
what was done wrong and how to do it
correctly.
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References
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Required
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Related
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FM
3-25.26
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GTA
05-02-012
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FREE Audio Version
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Misc. Information
For
55 years, this has been the basic guidebook for enlisted leaders
of the Army.
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