Land Navigation/Map Reading

What are the basic colors of a map, and what does each color represent?

Black - Indicates cultural (man-made) features such as buildings and roads, surveyed spot elevations, and all labels.

Red-Brown - The colors red and brown are combined to identify cultural features, all relief features, non-surveyed spot elevations, and elevation, such as contour lines on red-light readable maps.

Blue - Identifies hydrography or water features such as lakes, swamps, rivers, and drainage.

Green - Identifies vegetation with military significance, such as woods, orchards, and vineyards.

Brown - Identifies all relief features and elevation, such as contours on older edition maps, and cultivated land on red-light readable maps.

Red - Classifies cultural features, such as populated areas, main roads, and boundaries, on older maps.

Other - Occasionally other colors may be used to show special information. These are indicated in the marginal information as a rule.

Where is the Legend of the map found?

Lower left margin

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?

1. Index
2. Intermediate
3. Supplementary

How many Mils are in one Degree?

17.7 mils

How many North's are there on a military map?

1. True north
2. Magnetic north
3. Grid north

What shape are the contour lines that indicate a hill?

A hill is shown on a map by contour lines forming concentric circles. The inside of the smallest closed circle is the hilltop.

What shape are the contour lines that indicate a saddle?

A saddle is normally represented as an hourglass

What shape are the contour lines that indicate a valley?

Contour lines forming a valley are either U-shaped or V-shaped.

What shape are the contour lines that indicate a Ridge?

Contour lines forming a ridge tend to be U-shaped or V-shaped. The closed end of the contour line points away from high ground.

What shape are the contour lines that indicate a depression?

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.

What shape are the contour lines that indicate a draw?

The contour lines depicting a draw are U-shaped or V-shaped, pointing toward high ground.

What shape are the contour lines that indicate a spur?

Contour lines on a map depict a spur with the U or V pointing away from high ground

What shape are the contour lines that indicate a cliff?

Cliffs are also shown by contour lines very close together and, in some instances, touching each other.

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 base line 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?

1. Hill
2. Ridge
3. Valley
4. Saddle
5. Depression

What are the 3 minor terrain features found on a military map?

1. Draw
2. Spur
3. Cliff

What are the 2 supplementary terrain features found on a military map?

1. Cut
2. Fill

What is an azimuth?

A horizontal angle, measured in a clockwise manner from a north base line, expressing direction.

What is vertical distance?

The distance between the highest and lowest points measured.

What is a contour interval?

The vertical distance between adjacent contour lines on a map.

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.

1. Compass-to-Cheek Method
2. Center-Hold Method

Are topographic symbols drawn to scale?

No

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 a declination diagram?

Shows the angular relationship between the magnetic north, grid north and true north

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

Large cities on a map are represented by what color?

Black

Name two ways to orient a map.

Use a compass, and/or terrain association

The arrow on a compass always points what direction?

Magnetic north

What is longitude?

Imaginary lines that run north to south, measures your horizontal placement

What is latitude?

Imaginary lines that run east to west, measures your vertical placement

What s a topographic map?

Portrays terrain and land forms in a measurable way as well as horizontal features of the positions represented

What does the term intersection mean?

Finding the location of an unknown point by sighting two or more known points

Why is a map so important?

When used correctly, a map can give you accurate distances, locations and heights, best routes key terrain features and cover and concealment information.

What does the term resection mean?

Resection is the method of locating one's position on a map by determining the grid azimuth to at least two well-defined locations that can be pinpointed on the map.

If you find a symbol on a map that is unknown to you, where would you look?

The marginal data, located on the outside lower portion of the map

How many scales are there on a compass, what are they?

There are two:
1. Degrees
2. Mils

What are the 4 quadrants on a map?

1. Northeast
2. Southeast
3. Northwest
4. Southwest

What are the three elements for a land navigation process known as Dead Reckoning?

1. Known starting point
2. Known distance
3. Known azimuth

What is the feature that makes the lensatic compass work well at night?

The dials and needles are luminous

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

What is a contour level?

It is the vertical distance between contour lines. The amount of the contour level is located in the Marginal Information
on the map.

The border line around the edge of the map is called the what?

Neat Line

You must find at least how many known locations on a map and the actual ground in order to plot your location accurately?

At least 2

What are the three main map sizes?

1. Small
2. Medium
3. Large

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

How close will a four-digit grid coordinate get you to your point?

1000 meters

What is resection?

The method of locating one's position on a map by determining the location to at least two well-defined locations that can be pinpointed on the map (finding your place by using other defined locations)

What is modified resection?

method of locating one's position on the map when located on a linear feature on the ground (road, river, railroad) (the intersection of the linear feature and identifiable land feature is your position)

How do you find the elevation of a hilltop?

Add 1/2 the contour interval to the elevation of the last contour line

How do you find the elevation of a depression?

Subtract 1/2 the contour interval from the elevation of the last contour line