FMF 114 Land Nav Flashcards
Sheet Name
A map is named after the most prominent cultural or geographical feature.
Name is found in 2 places:
-Center of the upper margin
-Right or left side of the lower margin
Sheet Number
Used as a reference number for that map sheet.
Found in two places:
-Upper right margin & lower left margin
Scale
A representative fraction that gives you the ratio of a distance on the map to the corresponding distance on the earth’s surface.
Elevation Guide
A miniature characterization of the terrain shown.
Terrain is shown by bands of elevation, spot elevations, and major drainage features.
Elevation guide helps you rapidly identify major land forms.
Declination Diagram
Indicates the angular relationships of true north, grid north, and magnetic north.
Bar Scales
Used to convert map distance to ground distance.
Legend
Illustrates and identifies the topographic symbols used to depict some of the more prominent features on the map.
Grid Lines
A series of straight lines intersected at right angles and forming a series of squares.
Grid Squares
These intersect at right angles of the horizontal and vertical grid lines.
Basic Map Reading Rule
The designation of a point based on the principle: read right then up. Always read on the vertical grid lines then up within a grid square.
Grid Coordinates
4 digit: Locates a point to within 1000 square meters, on the map, which is called a grid square.
6 digit: will locate a point on the map within 100 meters.
8 digit: Will locate a point on a map within 10 meters.
True North
A line from any point on the earth’s surface to the North Pole.
Magnetic North
The Earth has a magnetic field that is close to (but not exactly on) the North Pole. The direction to magnetic north pole is indicated by the north-seeking arrow of your lensatic compass.
Grid North
Is established by using the vertical grid lines on the map. May be symbolized by the letters GN.
Hill
An area of high ground.
Is shown on a map by contour lines forming concentric circles, the inside of the smallest closed circle is the hilltop.
Ridge
A series of hills connected to each other near the top.
Saddle
A dip or low point between two areas of higher ground.
-Represented as an hourglass or figure eight shaped contour lines.
Finger/Spur
A short, continuous sloping line of higher ground, normally jutting out from the side of a ridge or hill.
Contour lines on a map depict a finger with the U or V pointing away from high ground.
Draw
A short, continuous sloping line of low ground, normally cut into the side of a ridge or hill. Often, there is a small stream running down the draw.
Contour lines on a map depict a draw with the U or V pointing towards high ground.
Depression
A low point in the ground or sinkhole. An area of low ground surrounded by higher ground in all directions, or simply a hole in the ground.
