Map Reading and Land Navigation (TC 3-25.26) Flashcards
What is the Field Manual for map reading and land navigation?
TC 3-25.26
What are the basic colors of a map, and what does each color represent?
Black - Indicates cultural (man-made) features
Red-Brown - Tall relief features such as contour lines on red-light readable maps.
Blue - Identifies water features
Green - Identifies vegetation with military significance
Brown - Identifies all relief features and elevation, such as contours on older edition maps
Red - Classifies cultural features, such as populated areas
Where is the Legend of the map found?
Lower left margin
What are military symbols?
Figures used to represent types of military organizations, installations, and activities
What are contour lines?
Imaginary lines on the ground connecting equal elevation, they represent high and low ground elevation.
What are 3 types of contour lines?
Index, Intermediate, and Supplementary
How many Mils are in one Degree?
17.7 mils
How many Norths are there on a military map?
Three: True north, Magnetic north, and Grid north
What shape are the contour lines that indicate a cut?
This contour line extends the length of the cut and has tick marks that extend from the cut line to the roadbed if the map scale permits this level of detail.
What shape are the contour lines that indicate a fill?
This contour line extends the length of the filled area and has tick marks that point toward lower ground. If the map scale permits, the length of the fill tick marks are drawn to scale and extend from the baseline of the fill symbol.
What must be done to a map before it can be used?
It must be oriented.
What are 5 major terrain features found on a map?
Hill, Ridge, Valley, Saddle, and Depression
What are the 3 minor terrain features found on a military map?
Draw, Spur, and Cliff
What are the 2 supplementary terrain features found on a military map?
Cut and Fill
What is a map?
A map is a graphic representation of a portion of the earth’s surface drawn to scale, as seen
from above.
What is an azimuth?
A horizontal angle, measured in a clockwise manner from a north baseline, expressing direction.
What is a contour interval?
The vertical distance between adjacent contour lines on a map.
What is the distance between grid lines on a combat map?
1 kilometer or 1000 meters
How many mils are there in a circle?
6400 mils in 360 degrees
Which north is used when using a military map?
Magnetic north when using a compass, and grid north when using the map
How would you hold a lensatic compass?
Away from metal (weapons, electrical devices), level and firm
Name two ways to hold a compass?
Compass-to-Cheek Method and Center-Hold Method
Are topographic symbols drawn to scale?
No
What do topographic symbols represent?
Man-made and natural features
In military symbols, what colors are used for a map overlay and what do they represent?
Blue- Friendly forces
Red-Enemy forces
Black- boundaries
Yellow-contaminated area both friendly and enemy
Green- engineer obstacles, both friendly and enemy
What is Back Azimuth?
The opposite direction of an azimuth.
How do you figure out a back azimuth?
To obtain a back azimuth from an azimuth, add 180 degrees if the azimuth is 180 degrees or less; subtract 180 degrees if the azimuth is 180 degrees or more
What is the general rule for reading military grid coordinates?
Right and UP
How many sights does a compass have?
2
What is a benchmark?
A man-made marker showing points of elevation
What are parallels of latitude?
Measured distances going north or south of the equator
What does UTM stand for?
Universal Transverse Mercator
The lensatic compass has a bezel ring; each bezel ring click is equal to how many degrees?
3
How many times would the bezel ring click if it were fully rotated?
120
Large cities on a map are represented by what color?
Black
Name two ways to orient a map?
Use a compass and terrain association
What does the term FLOT mean?
Forward Line Of Troops
How many scales are there on a compass, what are they?
There are two: Degrees and Mils
What are the 4 quadrants on a map?
Northeast, Southeast
Northwest, Southwest
What are the three elements for a land navigation process known as Dead Reckoning?
The known starting point, Known distance, and Known azimuth
What is the feature that makes the lensatic compass work well at night?
The dials and needles are luminous
What is the name of the map system that the U.S. uses?
UTM
On a lensatic compass there are two rings, an outer black ring and an inner red ring, what are they used for?
The inner red ring is used to find degrees, and the outer black ring is used to find mils
Name 3 field expedient methods of determining direction
The shadow-tip method, the watch method, and the North Star method
Name the different slopes found on a map.
Gentle, Steep, Concave, and Convex
What are two methods of measuring an azimuth?
Compass and a protractor
How close will an eight-digit grid get you to your point?
10 meters
How close will a six-digit grid coordinate get you to your point?
100 meters
What would you use on a map to measure actual ground distance?
The bar scale
What navigation methods are there?
Dead Reckoning and Terrain Association
What does OCOKA stand for?
Observation, Cover & Concealment, Obstacles, Key Terrain and Avenues of Approach.
What is the first step to land navigation?
Orienting the Map
What are the start points for vertical measurement of elevation on a standard military map?
The datum plane or mean sea level
What does GPS stand for?
Global Positioning System
What are the three major parts of the lensatic compass?
Cover, Base and Lens
Name two ways to determine your location on a map
Intersection and Resection
How many grids is the world divided into?
60 grid zones
