S. 114 land nav Flashcards Preview

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Flashcards in S. 114 land nav Deck (56):
1

what is a map named after

most prominent cultural or geographical feature. largest city on the map where possible

2

where is the sheet name located

center of upper margin and either right/left side of lower margin

3

what is a sheet # used for

reference # for that map sheet

4

the sheet # is found in what 2 places

upper right and lower left margin

5

what representative fraction does a scale offer

ratio of a distance on the map to the corresponding distance on the earths surface

6

where is the scale located

upper left margin after the series name and center of the lower margin

7

what is the purpose of the elevation guide

helps you rapidly ID major land forms

8

where is the elevation guide located

lower right margin

9

what does the declination diagram indicate

the angular relationship of true north, grid north, and magnetic north (located in lower margin)

10

bar scales are used to convert what

map distance to ground distance

11

where are bar scales located

center of the lower margin

12

the legend helps ID what

topographic symbols

13

where is the legend located

lower left margin

14

what are grid lines

straight lines intersected at right angles forming a series of squares

15

how do grid squares measure on the most common military map

1,000x1,000 meters

16

what is the basic map reading rule

read right the up

17

a four digit grid coordinate locates a point within how many square meters

1,000

18

a six digit grid coordinate locates a point within how many square meters

100

19

a 8 digit grid coordinate locates a point within how many square meters

10

20

what is true north

a line from any point on the earths surface to the north pole

21

how can true north be located at night

north star

22

when is true north utilized

when traveling without a compass

23

how is true north represented on the declination diagram

a line ending with a star

24

how is magnetic north indicated

north seeking arrow of lensatic compass

25

how is magnetic north symbolized on the declination diagram

a line ending with a half arrowhead

26

how is grid north indicated on the declination diagram

GN

27

what must be used to work with an azimuth measured from grid north

protractor

28

define hill

an area of high ground

29

how is a hill depicted on a map

contour lines forming concentric circles

30

define ridge

series of hills that are connected to each other near the top

31

define saddle

a dip or low point between two areas of higher ground

32

how is a saddle depicted on a map

hourglass or figure-eight shaped contour lines

33

define finger/spur

short, continuous sloping line of higher ground, normally jutting out from the side of a ridge or hill

34

how is a finger depicted on a map

U or V pointing AWAY from high ground (ground slopes down in 3 directions)

35

define DRAW

short, continuous sloping line of LOW ground normally cut in the side of a ridge or hill

36

how is a draw depicted on a map

U or V pointing TOWARD high ground

37

define depression

low point in the ground or a sink hole. surrounded by higher ground in all directions

38

how is a depression indicated on a map

closed contour lines that have tick marks pointing toward low ground

39

what does the cover contain on a lensatic compass

sighting wire and two luminous sighting dots for night navigation

40

how is the floating dial mounted

on a pivot

41

what does the floating dial consist of

magnetic needle, luminous arrow and the letters E (90º) and WEST (270º) printed on the dial

42

what are 2 scales on the floating dial

outer denotes MILS (black) inner denoted (degrees) red

43

MILS are normally used by what

arty, tank, mortar gunnery

44

what does a MIL express

size of an angle formed when a circle is divided into 6,400 angles with the vertex at the center

45

what formula is used to convert degrees to mills

multiply degrees by 17.78
6,400 ÷ 360 = 17.78

46

what is the purpose of the glass encasemnent

houses the floating dials and contains a fixed black index line

47

what is a bezel ring

device that clicks when turned. 120 clicks when rotated fully. 1 click 3º

48

where is the thumb loop attached

the base

49

what is the rear sight used for

lock the floating dial

50

why must the rear sight be opened greater than 45º

allow the floating dial to float free

51

what is the lens used for

read the floating dial

52

what is the angular difference between grid north and magnetic north called

G-M angle

53

how should G-M angle be rounded

nearest whole degree

54

how does location by inspection work

estimating your relation to several prominent features

55

why is it better to use two-point resection vs one-point

doesn't rely on ability to accurately estimate

56

how far apart should two prominent features be when using two point resection

at least 30º but no more than 150º