114 Land Navigation Fundamentals

Front 1

Discuss sheet name:

Back 1

-Map named after the most prominent cultural or geographical feature.
-Whenever possible, the name of the largest city on the map is used.

-Found in two places: center of upper margin or right or left side of lower margin.

Front 2

Discuss sheet number:

Back 2

-Reference number for that map sheet

-Found in two places; upper right or lower left

Front 3

Discuss scale:

Back 3

-Ratio of distance from map to corresponding earth surface
-1:50,000= 1 inch for 50,000 inches

-Found both in upper left margin after the series name and in the center of the lower margin.

Front 4

Discuss elevation guide:

Back 4

-Miniature characterization of the terrain shown

-Found in lower right margin

Front 5

Discuss declination diagram:

Back 5

-Indicated angular relationship between true north, grid north and magnetic north
-Recent maps have note on how to convert azimuths from grid to magnetic and magnetic to grid

-Located in the lower margin

Front 6

Discuss bar scale:

Back 6

-Used to convert map distances to ground distances.
-May have three or more bar scales, each with different unit of measurement.

-Located in center of lower margin

Front 7

Discuss legend:

Back 7

-illustrates and identifies topographical symbols such as railroad tracks, buildings and swamps.

-Located in lower left margin.

Front 8

Discuss grid lines:

Back 8

-Series of lines that intersect at right angles and form squares.
-Two digits are printed at each end of the grid line, same two digits appear at intervals along the grid line on the face of the map; called principle digits.

Front 9

Discuss grid squares:

Back 9

-Intersect at right angles at the horizontal and vertical grid lines.
-Most common grid squares measure 1000 meters by 1000 meters.

Front 10

Basic map reading rule

Back 10

-Read right then up
-Always read right on the vertical grid then up on the horizontal grid.

-Allows you to identify a grid square and locate a point within a grid

Front 11

Discuss four digit grid:

Back 11

-within 1000 square meters
-called a grid square

Front 12

Discuss six digit grid:

Back 12

-located a point on the map within 100 meters

Front 13

Discuss eight digit grid:

Back 13

-located a point on the map within 10 square meters

Front 14

Discuss true north:

Back 14

-Line from any point on the earths surface to the North pole
-Can be found at night by locating the North star
-Usually on the declination diagram as a line ending with a star
-Used when navigating without a compass

Front 15

Discuss magnetic north:

Back 15

-The earth has a magnetic field that is close to, but not exactly on, the North pole.
-Magnetic north is indicated by the north seeking arrow of the lensatic compass.
-Usually on the declination diagram as a line with a half arrow head

Front 16

Discuss grid north

Back 16

-Established by using the vertical grid lines on a map
-Symbolized on the declination diagram by the letter GN
-Used with a protractor and a map

Front 17

Define hill:

Back 17

-Area of high ground, that slopes down in all directions.
-smallest circle is the top

Front 18

Define ridge:

Back 18

-Series of hills that are connected to each other near the top

Front 19

Define saddle:

Back 19

-A dip or low point between two areas of higher ground
-If you are in a saddle, there is high ground in opposite directions, and low ground in the other directions
-Represented as an hour glass or figure eight

Front 20

Define finger/spur:

Back 20

-Short,continuous sloping line of higher ground, normally jutting out from the side of a ridge or hill
-Represented as a U or V pointing away from higher ground.

Front 21

Define draw:

Back 21

-Short, continuous sloping line of low ground, normally cut into the side of a ridge or hill.
-Little or no room exists within its confines
-U or V pointing toward high ground

Front 22

Define depression:

Back 22

-Low point in the ground or sink hole
-Tick marks

Front 23

What are the parts of the lensatic compass?

Back 23

-Cover

Base
-Floating dial
-Glass encasement
-Bezel ring
-Thumb loop
-Rear sight
-Lens
-Rear sight slot
-Lens
-Rear sight slot

Front 24

Discuss "floating dial":

Back 24

-Luminous arrow pointing to magnetic north
-E and W are printed on the dial
-East 90 degrees
-West 270 degrees

-Two scales: outer, black, MILS
inner, red, DEGREES

Front 25

Glass encasement

Back 25

houses the floating dial and contains a fixed black index line.

Front 26

Bezel ring

Back 26

-device that clicks when turns
-contains 120 clicks when fully rotated

Front 27

Rear sight

Back 27

-used to lock the floating dial
-must be opened more than 45 degrees to allow the dial to float freely

Front 28

Lens

Back 28

Used to read the floating dial

Front 29

Rear sight slot

Back 29

Used in conjunction with the front sighting wire when aiming at objects

Front 30

Grid azimuth

Back 30

Azimuth measured with a protractor (measured from grid north)

Front 31

Magnetic azumith

Back 31

-Determined with a compass

Front 32

What is the definition of G-M angle?

Back 32

-Angular difference between grid and magnetic north
-Grid-Magnetic angle

Front 33

What diagram displays the difference between grid and magnetic north?

Back 33

-Declination diagram

Front 34

To convert a magnetic azumith to a grid azimuth, do what?

Back 34

-add G-M angle

Front 35

What are three methods of determining your position?

Back 35

-Location by inspection
-Location by one point resection
-Location by two point resection.