Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/82

Click to flip

82 Cards in this Set

  • Front
  • Back
what document covers map reading and land navigation?
FM 3-25.26
What is a map?
A graphic representation of the earth's surface, drawn to scale as seen from above.
What's the purpose of a map?
To provide accurate information about the existence, location and distance between ground features like terrain, elevation,populated areas, routes of travel and communication
What is the scale of a map?
The ratio of ground distance to map distance and expressed in a fraction.
How many map scales are there and what are the names?
There are three map scales: small, medium, large
Name several types of maps.
Topographic map, planimetric map, photomap, terrain model.
What is a topographic map?
A map that portrays the layout of terrain features, as well as relief, or the vertical distance of the feature
What is a photomap?
An aerial photograph of a portion of the earth's surface on which grid lines, place names, and approximate scale and direction have been added
What is a planimetric map?
A map that only shows the horizontal positions of features. It differs from a topographic map in that it omits relief, usually represented by contour lines.
What is marginal information?
Instructions about the map's use, size, area.
Where is the map sheet name found?
Two places: the center of the upper margin and either the right or left side of the lower margin.
What is a map usually named after?
The most prominent geographical or cultural feature. Whenever possible it is named after the largest city on the map.
Where is a map sheet number found?
In two places: the upper right and lower left margin
Where is the map series name found?
Its found in the upper left margin.
Where is the series number found?
The upper right and lower left margins
Where is the scale of a map found?
In the upper left margin after the series name, and in the lower margin at the center
Where is the edition number of a map found?
The upper margin and in the lower left margin.
What does an edition number represent?
It represents the age of a map - the higher the number the more recent the edition of the map. The initials, or the abbreviation after the edition number indicates who made the map.
Where is the declination diagram found?
It's located in the lwer margin of large-scale maps
What is a declination diagram?
It shows the angular relationships of true north, grid north and magnetic north.
Where are the bar scales of a map located?
In the center of the lower margin.
What is a bar scale?
A ruler used to convert map distance to ground distance.
What are the usual three units of measure in a bar scale?
They are meters, statute miles, nautical miles.
Where is the contour interval note found?
Usually below the bar scales in the middle of the lower margin.
What is a contour interval?
The vertical distance of the space between the contour lines. In more recent maps that distance or space is given in meters instead of feet.
Where is the legend of a map found?
In the lower left margin.
What is in a map legend?
The symbols that represent topographic features. The symbols are not always the same.
How many colors does a mapusually have?
Five
What are the colrs?
Black, blue, green, brown, red/reddish brown
What do the colors of a map stand for?
Black indicates man-made features like buildings and roads. Blue identifies water features. Green is for vegetation with mlitary significance. Brown identifies all relief features and elevation, as well as contour lines on older maps. Red is used for cultural features such as populated areas, main roads, and on older maps it indicates boundaries.
What is longitude?
A measure of distance east or west of the prime meridian.
In what city is the prime meridian?
Greenwich, England
In which direction are the lines of longitude drawn on a map?
North and south.
Lines of longitude are also known as what?
Meridians.
What is latitude?
The measure of distance north or south of the equator.
What is the starting point for latitude?
The equator
Lines of latitude are also known as what?
Parallels, because they run parallel to the equator.
What type of map system does the US military use?
The universal transerse Mercator (UTM) grid
What portion of the world is a UTM map designed for?
That part of the world between lat 84 degrees north and lat 80 degrees south
What is a basic rule for finding coordinates on a map?
Beginning from the left hand corner, read right and up.
How close will you get to a location with an eight digit grid coordinate?
Within 10 meters
What information is used to make a map useful?
Marginal data
What is the difference between an aerial photograph and a photomap?
A photomap is a reproduction of an aerial photograph on which grid lines, marginal data, place names and other important data have been added
What is a map overlay and what is on it?
A sheet of clear plastic or transparent paper with information plotted on it at the same scale as the map or aerial photograph.
what is a map oerlay used for?
Shows current information about friendly and enemy troop positions, as well as any other pertinent data a leader may need to know about a certain area.
Name the three types of contour lines.
Index, intermediate, supplementary.
What are intermediate contour lines?
Intermediate contour lines fall between the index lines, are finer and are not numbered.
What are supplementary lines?
The resemble dashes. They show sudden changes in elevation of at least half the contour interval.
How does an index contour line differ from the other types of lines?
Index lines are heavier, have an elevation number at some point along the line, and occur every fifth line.
How is water flow determined on a map?
Contour lines will form a "V" which will point upstream.
How are valleys and draws shown on a map?
By "U" or "V" shaped contour lines.
What is an azimuth?
Its a direction - a horizontal angle which is measured in degrees or mils from the north.
What is a back azimuth?
An azimuth that is 180 degrees in reverse of a given azimuth.
How is a back azimuth found?
If the given aziumth is 180 degrees or less - add 180 degrees. If the azimuth is 180 degrees or more, subract 180 degrees.
What is resection?
Finding your unknown position by using the back aziumth of two known points. Draw lines from the known points. Where they intersect is your location. Remember to convert all magnetic azimuths to grid azimuths.
What is intersection?
Finding an unknown point by shooting an aziumth to it from two known points. The location is where the lines of azimuth intersect. Remember to convert the magnetic azimuths to grid azimuths.
Name the five major terrain features of a map.
Hill, ridge, valley, saddle, depression.
What are the minor terrain features?
Draw, spur, cliff, cut and fill
Name some types of compasses.
Lensatic, artillery, wrist/pocket and protrator.
What are the two most common compasses used in the army?
The lensatic and artillery compasses
How many scales are on the lensatic compass?
Two. One scale is in degrees, the other is in mils
How many mils are on a compass?
6400
What branch of the army uses mils?
The artillery
An artillery compass is also known as what type of compass?
An M-2 compass
How many degrees on a compass?
360
Hame three parts of a compass.
The three main parts are the base, cover and lens. Also, there is the sighting wire, graduated straight edge, bezel ring, floating dial, thumb loop, rear sight, sighting slot, luminous magnetic arrow, short luminous line, fixed black index line, luminous sighting dots.
What is the bezel ring and how is it used?
It is a ratchet device that clicks when turned. It will click 120 times when fully rotated, and each click is equal to three degrees
Why does the bezel click?
It was designed as an aid to determine degrees during nighttime use.
Name two characteristics of the lensatic compass that allow it to be used at night
The luminous sighting dots, luminous magnetic arrow, short luminous line, the click of the bezel ring, and a lumious E and W.
What are the two methods for holding a compass?
The centerhold technique and the compass-to-cheek technique.
What affects the performance of a compass?
Metal objects and sources of electricity.
Define magnetic declination.
The variation of the true north from the magnetic north. The declination variation is found in the declination diagram at the bottom margin of the map.
What is a bench mark?
A surveyor's sign which indicates elevation.
How would you hold a lensatic compass?
Level and firm - away from electrical equipment or metal equipment such as weapons.
Describe the fastest way to orient a map.
Place a compass on a map and align it with the grid lines insuring that the compass needle points north.
How would you orient a map without a compass?
By aligning it with the observable terrain features
Name the quadrants of a map.
Northeast, Northwest, Southeast, Southwest
What three elements are necessary for dead reckoning in land navigation?
Known starting oint, known distance and known azimuth.
What is "FLOT"?
That is the abbreviation for forward line of own troops.
What colrs are used in a map overlay, and what do they mean?
Black = boundries
Blue = friendly forces
Red = enemy forces
Yellow = contaminated area
Green = engineer obstacles
When colors are not used what symbol is used for enemy forces?
Double Lines
What size unit is indicated by three dots?
A platoon or detachment.