basic map reading
TRANSCRIPT
REFERENCE: UNITED STATE ARMY MANUAL DEPARTMENT OF THE ARMY, 1987
To provide the Students the knowledge and develop their skill in map reading and to impart to them the importance of map information in the future planning.
Definition, Importance and Caring of Map
Categories and uses of Maps Marginal Information Colors used on a Military Map Grid Coordinates Scale and Distance Directions
MAP- is a graphic representation of the earth’s surface or part of it, drawn into scale as seen from above.
A map can give accurate information.
It becomes more & more necessary to rely upon maps.
By necessity, planning must be done on maps.
Adequate supply of maps.
• Protect fm water, mud & tearing.• Map should be carried in
waterproof cases, in pocket or in place where it is handy for use.
• If you put a mark on a map, use of pencil.
• Use light lines so they maybe erased easily without smearing and smudging, or leaving marks that may later cause confusion.
• Should be folded properly.
ACCORDING TO SCALE Scale - is expressed as a
fraction and gives the ratio of map distance to the ground distance.
Small Scale Medium Scale Large Scale
• The map scale is 1:50,000• RF = 1/50,000• The map distance from point A to
B is 5 units• 5 X 50,000 = 250,000 units of
ground distance
Types of Maps Planimetric map Topographic mapPhotomap Joint operations
graphics Photomosaic map
Types of Maps Terrain modelMilitary city map Plastic relief mapSpecial maps
Military Use
General map Strategic map Strategic-Tactical map Tactical map
Artillery map Situation map
Sheet Name Sheet Number Series Name Scale Serial Number Edition Number Index to Boundaries
Adjoining Sheet Diagram Elevation Guide Declination Diagram Bar Scale Contour Interval Note Spheroid Note Projection note
•Sheet Name:
CAVITE
Sheet Number:
SHEET 7171 I
Series Name:
PHILIPPINES
Scale:
PHILIPPINES
1:50,000
7173 III 7272 III
7171 II7171 III
7172 II
7171 IV 7271 IV
7271 III
7171 I
Adjoining Sheets Diagram
Bar ScalesLegend
Serial Number Example: S701
S – word series7 – scale of the map as follows;
8 – 1:25,000, 7 – 1: 50,000 6 – 1:100,000
0 – Sub-geographical area as follows;0 – Philippines 1 – Luzon 2 – Visayas 3 – Panay4 – Sulu 5 – Mindanao
Black – man-made objects Blue – drainage/bodies of
water Brown – relief & elevation Green –vegetation
Red – roads, built-up areas and special features.
Reddish-Brown – cultural features, all relief
features and elevation
Representative Fraction (RF) Example is as shown:
The map scale is 1:50,000 or RF = 1/50,000
The map distance from point A to B is 5 units
5 x 50,000 = 250,000 units of ground distance
Comparison with the Ground distance
Example: 1/X, RF = 1/X = MD/GDMD = 4.32 centimetersGD = 2.16kms (216,000 cms)
1 4.32 4.32X = 216,000 X 216,000 4.32 4.32
X =50,000
RF
RF = 1/X = MD/GDEx: MD = GD/Denominator of RF
GD = 2,200 metersRF = 1:50,000
MD = 2,200/50,000= 0.044 mtr x 100 (cm in a mtr)= 4.4 centimeters
Graphic (Bar) Scales
1 ½ 0 1 2 3 Substitute Miles
1 ½ 0 1 2 3 Nautical miles
Meters 1000 0 1 2 3 4 5 Kilometers
Secondary Scale Primary Scale
Transferring map distance to paper strip
Measuring straight-line map distance
Measuring curved lines
Method of expressing Directions Degree – the most common unit
of angular measure. Mil – used in arty, tank & mortar
gunnery. Grad – a metric unit of measure
found on some foreign maps.
Base Lines True North
Magnetic North
Grid North GN or Y
Azimuths - is a horizontal angle, measured in a clockwise manner fm a north base line. Back Azimuth – reverse direction
ADD 180O - AZIMUTH IS 180O OR LESS. SUBTRACT 180O -
AZIMUTH IS 180O OR MORE.
270O
0 or 360O
90O
180O
Azimuth
Back Azimuth
115 O
295 O
Back Azimuth
Azimuth less than 180 degrees - plus 180 degrees
Azimuth more than 180 degrees - minus 180 degrees
Method of Locating Points Intersection Resection Polar Plot Modified resection
Directions
®Methods of Expressing Directions
Degree ( 1 degree = 60 min)
Mil (Artillery, tank, and mortar gunnery)
90 270
0 or 360
180
BA
SE L
INE
Direction Line
ORIGIN64 degrees
Grid Square Grid Coordinate scales Determining grids Precision
RULE OF DUMB
READ RIGHT AND UP
GS67 88
66 67 68 69
90
89
88
87
GS68 88
66 67 68 69
90
89
88
87
GS67 89
66 67 68 69
90
89
88
87
GS68 89
66 67 68 69
90
89
88
87
GS68 87
66 67 68 69
90
89
88
87
GS66 88
66 67 68 69
90
89
88
87
GS66 89
66 67 68 69
90
89
88
87
66 67 68 69
90
89
88
87
6 DIGITSNEAREST 100 METERS
66 67 68 69
90
89
88
87
1 2 3 4 5 6 7 8 9
1
2
34
567
89
67
89
88
68
GC 67 ___ 88____5 5GC 675885
1 2 3 4 5 6 7 8 9
1
2
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567
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67
89
88
68
GC 67 ___ 88____7 6GC 677886
1 2 3 4 5 6 7 8 9
1
2
34
567
89
67
89
88
68
GC 67 ___ 88__2 9GC 672889
1 2 3 4 5 6 7 8 9
1
2
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GC 67 ___ 88___9 1
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1 2 3 4 5 6 7 8 9
1
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GC 67 ___ 88___0 0GC 670880
1 2 3 4 5 6 7 8 9
1
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GC 67 ___88___7 0GC 677880
1 2 3 4 5 6 7 8 9
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GC 67 ___88___0 7GC 670887
1 2 3 4 5 6 7 8 9
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GC 68 ___ 88___0 0GC 680880
1 2 3 4 5 6 7 8 9
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GC 67 ___ 89___0 0GC 670890
1 2 3 4 5 6 7 8 9
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GC 68 ___ 89___0 0GC 680890
1 2 3 4 5 6 7 8 9
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GC 67 ___ 88___7 6GC 677886+_100
1 2 3 4 5 6 7 8 9
1
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89
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GC 67 ___ 88___7 6GC 677886+_100
1 2 3 4 5 6 7 8 9
1
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89
67
89
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68
GC 67 ___ 88___7 7GC 677887+_ 100
1 2 3 4 5 6 7 8 9
1
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567
89
67
89
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68
GC 67 ___ 88___8 7GC 677887+_ 100
8 DIGITSNEAREST 10 METERS
1 2 3 4 5 6 7 8 9
1
2
34
567
89
67
89
88
68
GC 67 ____ 88____7 7
4 0GC 67748870
1 2 3 4 5 6 7 8 9
1
2
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89
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GC 67 ____ 88____7 7
0 3GC 67708873
1 2 3 4 5 6 7 8 9
1
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89
67
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68
GC 67 ____ 88____7 6
0 5GC 67708865
1 2 3 4 5 6 7 8 9
1
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567
89
67
89
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68
GC 67 ____ 88____4 4
5 0GC 67458840
