114 LAND NAVIGATION FUNDAMENTALS

Question 1

explain sheet name and location

Answer 1

A map is named after the most prominent cultural or geographical feature.
Whenever possible, the name of the largest city on the map is used.
The sheet name is found in two places:
center of the upper margin.
either the right or left side of the lower margin

Question 2

explain sheet number and location

Answer 2

Sheet Number
The sheet number is used as a reference number for that map sheet.
It is found in two places:
the upper right margin.
the lower left margin.

Question 3

explain scale

Answer 3

The scale note is a representative fraction that gives you the ratio of a
distance on the map to the corresponding distance on the earth’s surface.
For example, the scale note 1:50,000 on many maps indicates that one inch
on the map equals 50,000 inches on the ground.
Maps with different scales will display different degrees of topographical
detail. For example, a map with a scale of 1:25,000 will give more detail than
a 1:50,000 map because one inch on the map represents only 25,000 inches
on the ground, rather than the 50,000 inches of the 1:50,000 map.
The scale is found both in the upper left margin after the series name and in
the center of the lower margin.

Question 4

explain elevation guide and location

Answer 4

Elevation Guide
The elevation guide is a miniature characterization of the terrain shown.
The terrain is shown by bands of elevation, spot elevations, and major
drainage features.
The elevation guide helps you rapidly identify major land forms.
It is normally found in the lower right margin

Question 5

explain Declination Diagram

Answer 5

Declination Diagram
This indicates the angular relationships of true north, grid north, and
magnetic north.
Recent edition maps have a note indicating how to convert azimuths from
grid to magnetic and from magnetic to grid next to the declination diagram.
The declination diagram is located in the lower margin.

Question 6

explain bar scale and location

Answer 6

Bar Scales
Bar scales are used to convert map distance to ground distance.
Maps may have three or more bar scales, each in a different unit of measure.
Exercise care when using the scales, especially in the selection of the unit of
measure.
The bar scales are located in the center of the lower margin.

Question 7

explain legend on map

Answer 7

Legend
The legend illustrates and identifies the topographic symbols used to depict
some of the more prominent features on the map, such as railroad tracks,
buildings, and swamps.
The symbols are not always the same on every map.
Always refer to the legend to avoid error when reading a map.
The legend is located in the lower left margin

Question 8

explain grid lines

Answer 8

Grid Lines
Grid lines are a series of straight lines intersected at right angles and forming
a series of squares.
It furnishes the map reader with a system of squares similar to the block
system of most city streets.
Two digits are printed in large type at each end of the grid lines, and these
same two digits appear at intervals along the grid lines on the face of the
map. They are called principal digits.
They are of major importance to the map reader because they are the
numbers he will use most often for referencing points.

Question 9

explain grid squares

Answer 9

These intersect at right angles of the horizontal and vertical grid lines.
The most common military map contains grid squares that measure 1000
meters by 1000 meters (not 1000 square meters as many people think).
Any point located within the grid square is considered to be part of the grid
square.

Question 10

basic map reading rule

Answer 10

Basic Map Reading Rule
The designation of a point is based on the principle:
Read right then up.
Always read right on the vertical grid lines then up on the horizontal grid
lines.

Question 11

grid square identification

Answer 11

Grid Square Identification
It is important that all of you understand how to apply the map reading rule to
identify a grid square and locate a point within a grid square.

Question 12

The following grid coordinates will locate a point on a map within how many
meters: 4 digit

Answer 12

A four digit grid coordinate locates a point to within 1000 square meters, on the
map, which is called a grid square

Question 13

The following grid coordinates will locate a point on a map within how many
meters: 6 digit

Answer 13

six digit grid coordinate will locate a point on a map within 100 meters.

Question 14

The following grid coordinates will locate a point on a map within how many
meters: 8 digit

Answer 14

grid coordinate will locate a point on a map within 10 meters

Question 15

explain true north

Answer 15

True North
The true north line is a line from any point on the earth’s surface to the North
Pole.
True north can be found at night by locating the North Star, which always
points towards true north.
Usually represented on the declination diagram by a line ending with a star.
Used almost exclusively when navigating without a compass.

Question 16

explain magnetic north

Answer 16

Magnetic North
The earth has a magnetic field that is close to (but not exactly on) the North
Pole. The direction to this north magnetic pole is indicated by the northseeking arrow of your lensatic compass.
Magnetic north is usually symbolized on the declination diagram by a line
ending with a half arrowhead.
Anytime you use the compass to plan or follow an azimuth in the field, you
must work with azimuths measured from magnetic north.

Question 17

explain Grid north

Answer 17

Grid North
This base line is established by using the vertical grid lines on the map.
Grid north may be symbolized on the declination diagram by the letters GN.
Anytime you use a protractor in conjunction with a vertical grid line to
determine or plot an azimuth on a map, you must work with an azimuth
measured from grid north.

Question 18

explain hill

Answer 18

A hill is an area of high ground.
From a hilltop, the ground slopes down in all directions.
A hill is shown on a map by contour lines forming concentric circles.
The inside of the smallest closed circle is the hilltop.

Question 19

explain ridge

Answer 19

A ridge is a series of hills that are connected to each other near the top.
A ridge line may extend for many miles.
It may be winding or quite straight.
It may have a reasonably uniform elevation along its top or it may vary
greatly in elevation

Question 20

explain a saddle

Answer 20

Saddle
This is a dip or low point between two areas of higher ground.
A saddle is not necessarily the lower ground between two hilltops; it may be
simply a dip or break along a level ridge crest.
If you are in a saddle, there is high ground in two opposite directions and low
ground in the other two directions.
A saddle is normally represented as an hourglass or by figure-eight shaped
contour lines

Question 21

explain finger/spur

Answer 21

A finger is a short, continuous sloping line of higher ground, normally jutting
out from the side of a ridge or hill.
A finger is often formed by two roughly parallel draws.
The ground slopes down in three directions and up in one.
Contour lines on a map depict a finger with the U or V pointing away from
high ground.

Question 22

explain a draw

Answer 22

A draw is a short, continuous sloping line of low ground, normally cut into the
side of a ridge or hill.
Often, there is a small stream running down the draw.
In a draw, there is essentially no level ground. Therefore, little or no
maneuver room exists within its confines.
If you are standing in the middle of a draw, the ground slopes upward in
three directions and downward in the other direction.
Contour lines on a map depict a draw with the U or V pointing toward high
ground

Question 23

explain a depression

Answer 23

Depression
This is a low point in the ground or a sinkhole.
It is an area of low ground surrounded by higher ground in all directions, or
simply a hole in the ground.
Usually only depressions that are equal to or greater than the contour interval
will be shown.
On maps, depressions are represented by closed contour lines that have tick
marks pointing toward low ground

no not your mental state

Question 24

explain cover of compass

Answer 24

This protects the floating dial and the glass encasement.
It contains the sighting wire and two luminous sighting dots for night
navigation.

Question 25

explain the floating dial

Answer 25

This is mounted on a pivot so that it rotates freely when the compass is
held level.
It contains the magnetic needle.
A luminous arrow and the letters “E” and “W” are printed on the dial.
The arrow points to magnetic north.
Letters fall at the east (E) 90 degrees and (W) 270 degrees.
There are two scales:
outer - denotes MILS (black)
inner - denotes DEGREES (red).
**NOTE: Mil, is another unit of measure. The mil (abbreviated m) is mainly
used in artillery, tank, and mortar gunnery. The mil expresses the size of an
angle formed when a circle is divided into 6,400 angles with the vertex of the
angles at the center of the circle. A relationship can be established between
degrees and mils. A circle equals 6400 mil divided by 360 degrees, or 17.78
mils. To convert degrees to mils, multiply degrees by 17.78.

Question 26

explain glass encasement

Answer 26

This houses the floating dial and contains a fixed black index line

Question 27

explain bezel ring

Answer 27

This device that clicks when turned.
It contains 120 clicks when rotated fully.
Each click equals 3 degrees.
A short luminous line is used in conjunction with the north-seeking arrow
during night navigation.

Question 28

explain thumb loop

Answer 28

Thumb Loop
This is attached to the base.

Question 29

explain rearsight of compass

Answer 29

Rear Sight
This is used to lock the floating dial.
The rear sight must be opened more than 45 degrees to allow the
floating dial to float freely.

Question 30

explain lens of compass

Answer 30

Lens
This is used to read the floating dial.

Question 31

explain rear sight slot

Answer 31

Rear Sight Slot
This is used in conjunction with the front sighting wire when aiming at
objects.

Question 32

what are azimuths
and conversion notes

Answer 32

Azimuths measured with a protractor are grid azimuths (measured from grid
north),
Azimuths determined with the compass are magnetic azimuths (measured
from magnetic north).
You cannot follow a grid azimuth with a compass, nor can you plot a
magnetic azimuth with a protractor because of the angular difference
between grid north and magnetic north.
This angular difference (between grid north and magnetic north) is called the
G-M ANGLE (Grid-Magnetic angle).
The G-M angle varies for each map. Because of this angular
difference (the G-M angle), before you can plot a magnetic azimuth on
a map, you must convert it to a grid azimuth.
Before you can use a grid azimuth to navigate, you must convert it to a
magnetic azimuth.
Declination diagrams display the difference between grid and magnetic north.
A complete set of instructions is included in MOST declination diagrams for
your use in converting azimuths.
The G-M angle often is not expressed as a whole degree, such as 1/2
degrees or 7 degrees 15’.
Since you will not need to work with such precise numbers as minutes, round
the G-M angle off to the nearest whole degree.
If the G-M angle is 1/2o or 30’ then round the angle up to the next highest
whole degree.

Conversion Notes. Refer to the conversion notes that appear with the
declination diagrams explaining the use of the G-M angle.
One note provides instructions for converting a magnetic azimuth to a
grid azimuth.
The other provides instructions for converting a grid azimuth to a
magnetic azimuth.
The conversion (addition or subtraction) is governed by the direction of
magnetic north relative to grid north.
TO CONVERT A MAGNETIC AZIMUTH TO A GRID AZIMUTH ADD G-M ANGLE

Question 33

Discuss the technique used to orient a map using the following methods: compass

Answer 33

When orienting a map with a compass, remember that compasses measure
magnetic azimuths.
Since the north-seeking arrow of the compass points to magnetic north, pay
special attention to the declination diagram.
Use the following technique to orient your map.
With the map flat on the ground, place the straightedge (on the left
side of the compass) along the magnetic north arrow on the declination
diagram so that the cover of the compass is pointing toward the top of
the map. This will put the fixed black index line of the compass parallel
to the magnetic north arrow of the declination diagram
Keeping the compass aligned as directed above, rotate the map and
compass simultaneously until the north-seeking arrow is below the
fixed black index line on the compass. Your map is now oriented.

Question 34

Discuss the technique used to orient a map using the following methods: Terrain association

Answer 34

You can orient your map using terrain association when a compass is not
available or when you have to make quick references as you move across
country.
Using this technique requires careful examination of the map and the
features on the ground.
Identify prominent terrain features on the map that you can find on
the ground.
Align terrain features with the map, if there is a tower to your right
front, then orient the map so that the tower is to your right. If there is a
road off to your left, then the road on the map is parallel to the road on
the ground. Once all of the features are lined up, your map is oriented

Question 35

Discuss the technique for determining your position using the following methods

Answer 35

Location by Inspection
You are standing in the vicinity of several prominent features which can
easily be located on the map.
By orienting the map and estimating your relation to these features, you
should have no difficulty in determining your location.

Question 36

Location by One-Point-Resection

Answer 36

One-point resection is an accurate technique of determining your location
when you are on or near a linear feature that you can identify both on the
ground and on the map.
You must also be able to identify another prominent feature, both on ground
and on the map.
To determine your location by one-point resection follow these steps:
Identify the linear terrain feature that you are located on or near in
respect to the ground on your map.
Identify a prominent feature on the ground and locate that feature on
your map.
Using the compass-to-cheek technique, sight in on the feature and
read the magnetic azimuth
Convert the magnetic azimuth to a grid azimuth.
Convert this grid azimuth to a grid back azimuth.
With your protractor, plot this grid back azimuth from the feature on the
map and extend it until it crosses the linear feature.
Conduct a map inspection to verify your resection.
When selecting a terrain feature, choose one that is perpendicular to
the axis of the linear terrain feature so that when you plot the back
azimuth on the map, the line will cross the linear feature more or less
at a right angle

Question 37

Location by Two-Point-Resection

Answer 37

Usually you will find that you are not located on or near a prominent linear
feature Since the accuracy of a one-point resection under these conditions
depends on your ability to accurately estimate distance, it is better to use a
two-point resection.
The procedures for two-point resections are basically the same as for onepoint resections except you must select two features instead of one.
The back azimuths from each feature is determined and plotted on your map.
You are located at the point where these lines cross.
If you have a compass and a protractor then follow these steps:
Select two prominent features on the ground whose positions can be
located on the map.
These features should be at least 30o but not greater that 150o apart.
Using the compass-to-cheek technique, determine the magnetic
azimuth to each object.
Convert these magnetic azimuths to grid back azimuths.
With your protractor, draw the respective back azimuths from these
two points on your map
Extend the azimuth lines from these two points until they intersect.
You are located at the point where these two lines cross.
Conduct a map inspection to verify your position