Section 117 Land Nav

Question 1

Name the 12 Parts of the Lensatic Compass

Answer 1

• Luminous Sighting Dots
• Fixed Index line
• Sighting Wire
• Graduated Straight Edge
• Luminous Magnetic Arrow
• Short Luminous Line
• Lens
• Sighting Slot
• Floating Dial
• Bezel Ring
• Lens or rear sight
• Thumb loop

Question 2

What is a declination diagram

Answer 2

Shows relationships between True North, Magnetic North, and Grid North

Question 3

What is the Bar Scale on a mpa

Answer 3

Rulers used to convert map distance to ground distance for different units of measure

Question 4

What is an index contour line

Answer 4

Every fifth contour line which is heavier and numbered

Question 5

What is an intermediate contour line

Answer 5

Fall between index contour lines, finer than index lines

Question 6

What are supplementary contour lines

Answer 6

Resemble dashed line, usually represent half the change of contour lines and usually only shown where there is little elevation change.

Question 7

What size boxes do 6, 8, 10 digit grids correspond to

Answer 7

6 Digit: 100m squared
8 Digit: 10m squared
10 Digit: 1m squared

Question 8

What map features are red

Answer 8

Cultural (manmade) features, populated areas, main roads

Question 9

What map features are blue

Answer 9

Hydrography, water features

Question 10

What map features are black

Answer 10

Denotes buildings, roads, surveyed spot elevations and labels

Question 11

What map features are brown

Answer 11

Relief features and elevation, cultivated land on red-light readable maps

Question 12

What map features are red brown

Answer 12

Combined on red light readable maps to identify cultural features, relief features, and elevations

Question 13

What map features are green

Answer 13

Vegetation with military significance such as woods, orchards, vinyards

Question 14

What does a hill look like on a map

Answer 14

Think Target

Question 15

What does a Saddle look like on a map

Answer 15

Think Boobies

Question 16

What does a valley look like on a map

Answer 16

usually surrounded on 3 sides by high ground, usually has water running through it, contour lines form a U or V

Question 17

What does a depression look like on a map

Answer 17

Closed contour lines (circle) with hash marks

Question 18

What do draws/fingers look like on a map

Answer 18

• Draw, initial formation of a valley, U or V points to higher ground.
• Finger, U or V points away from higher ground

Question 19

What does a cliff look like on a map

Answer 19

Converging countour lines may have hashes pointing off the edge

Question 20

What does a cut look like on a map

Answer 20

Manmade, parallel lines with hash marks pointing to center

Question 21

What does a fill look like on a map

Answer 21

Manmade, parrallel lines with hash marks pointing out from center

Question 22

What is True North

Answer 22

Line pointing to the North pole, all longitude lines point to true north, usually represented by a star

Question 23

What is Magnetic North

Answer 23

The direction to the Magnetic North Pole, indicated by the North seeking magnetic needle of a compass, Line ends with a half arrowhead

Question 24

What is Grid North

Answer 24

Established using vertical lines on a map, usually marked by letters “GN” or “Y”

Question 25

How many Mils in 360 degrees

Answer 25

6400 mils

Question 26

What is an azimuth

Answer 26

Horizontal angle measured clockwise from a north base line (may be true, magnetic, or grid)

Question 27

What is a back Azimuth

Answer 27

“About face” Add or subtract 180 degrees depending on starting value.

Question 28

What is a grid azimuth

Answer 28

Calculated on a map, must be converted to magnetic to use compass

Question 29

How do you remember to add or subtract when going Grid to magnetic or vice versa

Answer 29

Major to General ADD (Mag to Grid = add)

General to Major SUBTRACT (Grid to Mag = Subtr)