Map Reading
What happens when a map is no longer needed?
It must be turned in to the proper authority.
What are the five major terrain features?
Hill, Valley, Ridge, Saddle, Depression
What type of compass does the Army use?
Lensatic compass
What are 4 methods to determine distance when it is not possible to use a map?
Pace count
Odometer
Subtense
Estimate range
What are the 3 types of north?
True north
Magnetic north
Grid north
What is the scale of most military topographic maps used for land navigation?
1:50,000
A U or V shape pointing uphill represents what?
Valley
What's an azimuth?
A horizontal angle measured clockwise from a north base line. Azimuth is the most common military method to express direction.
When using an azimuth, the point of where the azimuth originates is the center of an imaginary circle.
How do you use the Pace Count method to measure distance?
A pace is equal to one natural step, about 30 inches long. Walk an accurately-measured course and count the number of paces it takes to reach 100m.
Keep track of the distance traveled.
What is the key to success in land navigation?
Know where you are at all times.
Initial location is very important before starting movement.
On a standard large-scale topographic map, what features do Black, Red-Brown, Blue, Green, Brown, and Red represent?
Black - indicates cultural features
Red-Brown - combined to identify cultural features, all relief features, and elevation such as contour lines.
Blue - water features
Green - vegetation
Brown - all relief features and elevation, contour lines on older maps
Red - classifies cultural features on older maps
What terrain feature looks like an hourglass?
Saddle
What are the 2 techniques employed when using the lensatic compass?
Centerhold
Compass-to-cheek technique
What are some conditions that affect the Pace count in the field?
Slopes
Winds
Surfaces
Elements
Clothing
Visibility
What is declination?
The angular difference between 2 norths, magnetic and grid north.
What function does the Numerical scale of a map perform?
Relationship between the distance measured on a map and the corresponding distance on the ground.
Scale is usually written as a fraction called the representative fraction.
What terrain feature has tick marks on contour lines?
Depression
When a compass is not available, different techniques may be used to determine the four cardinal directions. What are 3 methods?
The shadow-tip method
Watch method
Star method
How do you use the 100-Meter Unit of Measure Method?
Visualize a distance of 100m on the ground. For ranges up to 500m, you determine the number of 100m increments between the two objects to measure. Beyond 500m, you select a point halfway to the object and determine the number of 100m increments to the halfway point, then double it to find the range to the object.
What is an intersection?
The location of an unknown point by succesively occupying at least 2 (preferably 3) known positions on the ground and then map sight on the unknown location. It is used to locate distant or inaccessible points or objects like enemy targets and danger areas.
How is ground distance between two points on a map determined?
By measuring between the same two points on the map and then multiplying the map measurement by the denominator of the RF or scale.
Example: The map scale is 1:50,000, making RF = to 1/50,000. The map distance from point A to point B is 5 units. Therefore, 5 x 50,000 = 250,000 units of ground distance.
What terrain feature is a line of high ground with lower ground on both sides?
Ridge
How do you use the Flash-to-Bang Method?
This method is used for determining range to an explosion or enemy fire. The count begins when the flash is seen. Count the seconds until weapon fire is heard. Interval may be measured with a stopwatch or by using a steady count, such as one-thousand-one, one-thousand-two, and so on, for 3 second estimated count.
Multiply the number of seconds by 330m to get the approximate range. Or divide by the conversion factor to determine distance.