# Locating Places on Map

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Locating Places on a
Map
Cardinal Points
   The four main directions of
a compass are known as
cardinal points. They are
north (N), east (E), south
(S) and west (W).

2
Intercardinal (Ordinal) Points
   Sometimes, the
intercardinal
(ordinal) points of:
•   north-east (NE),
•   north-west (NW),
•   south-east (SE) and
•   south-west (SW)
are shown on the
compass.

3
Compass Bearings
   This compass shows
degree
measurements from
0° to 360° in 10°
intervals with:
• north representing 0°
or 360°
• east representing 90°
• south representing
180°
• west representing
270°

4
Bearing
   The true bearing to a
point is the angle
measured in degrees in a
clockwise direction from
the north line. We will
refer to the true bearing
simply as the bearing.

5
Bearing Example
   For example, the
bearing of point P is
065º which is the
number of degrees in
the angle measured in
a clockwise direction
from the north line to
the line joining the
centre of the compass
at O with the point P
(i.e. OP).

6
Compass Points

360/000o
N
Half way between                              Half way between
North and West     NW                          North and East
NE

270o   W                                 E   090o

SW                    SE
Half way between                         Half way between
S
South and West                            South and East
180o
7
.
Bearings
360/000o
N
1. Measured from North.
060o
2. In a clockwise direction.                         60o
270o     W               E       090o
3. Written as 3 figures.

S

180o
N                            N                       N
315o

W        145o          E   W                    E     W                        E
230o                   315o

230o
145o                                                       8
S                            S                          S
A 360o                   Bearings          measure the bearing of
protractor is                                 each point from the
used to measure               360/000o          centre of the circle.
bearings.                                   (Worksheet 1)
350o     N       020o
315o                                       045o
NW
NE

290o
080o
270o    W                                          E     090o

250o                                      110o

SW                            SE
225o       210o                          135o
S       160o
180o
9
N
360/000o
030o
330o
Estimate the
315o                               045o
bearing of
each aircraft
290o                                                       from the
centre of the
075o

W 270o                                                             090o E

110o       Air Traffic
Control     250o
Controller
Tower
135o
225o
170o
200o
180o                                     10
2-Jun-11
S
N
360/000o
010o
325o               7
040o            Estimate the
8
310o                                     1                       bearing of
ACE
060o     each aircraft
Controller
11
from the
contest
4
12                              centre of the
280o
2

W 270o                                                                             090o E
3
5
250o                     10                                         Air Traffic
Control                                                 9                         Controller
120o
Tower
235o
6

195o                            155o
180o    Worksheet 2                             11
2-Jun-11
S
Bearings

Measuring the bearing of one point from another.

To Find the bearing of Q from P.
N

P

118o
1. Draw a straight line between both points.
Q
2. Draw a North line at P.

3. Measure angle between.                                          12
Bearings

Measuring the bearing of one point from another.

To Find the bearing of P from Q.

N
298o
P

1. Draw a straight line between both points.
Q
2. Draw a North line at Q.

3. Measure angle between.                               13
Bearings: Fixing Position
Trainee pilots have to to learn to be cope when the unexpected
happens. If their navigation equipment fails they can quickly find
their position by calling controllers at two different airfields for
a bearing. The two bearings will tell the pilot where he is. The
initial call on the controllers radio frequency will trigger a line on
the radar screen showing the bearing of the calling aircraft.

Airfield (A)
283.2 MHZ UHF

170o
255o

Airfield (B)
306.7 MHZ UHF
Thankyou

14
Bearings

000/360o
N

270o   W              E   090o

S

180o
15
Grid Systems
   The most common way to locate a place on a
map is to use a grid system.

   A grid system allows the location of a point on a
map (or on the surface of the earth) to be
described in a way that is meaningful and
universally understood.

16
Simple Grid System
   A simple grid is shown with the location of a point of
interest that we want to describe

   In order for a point designation on a grid to be
meaningful, there must be an origin to the grid which can
be used to reference the point to.

17
Alphanumeric Grid
   An alphanumeric grid
uses letters and numerals
to identify squares on a
grid pattern.

18
Map Grid (Military Grid)

A method to locate points on a map


With this method, a system of numbered lines is
superimposed on a map and position is stated by
quoting the numbers of the lines that intersect at
the point in question.

19
Using the Military Grid

For instance, let's
utilize the military grid
to determine which
grid square the church
is located in.

20
Identifying Grid Squares -
Easting

First, go to the Western
edge of the grid square that
the object is in first. Then
from that western edge, go
up or down until you come
to a number. In this case,
going up or down yields the
number 91. These are the
first two digits for the square
that the church is in.

21
Identifying Grid Squares -
Northing

Secondly, go to the
Southern edge of the grid
square that the object is in.
From that southern edge,
go across until you come to
a number. In this case, the
number is 94. This
represents the third and
fourth digits for the square
that the church is in.


Hence, the church is in
grid square 9194
22
Six Digit Military Grid Method

With this method, you start out
exactly the same way as the four
how far over from that western edge
is the church? To determine this,
picture the grid square as if it was
divided into ten equal vertical
sections.


The church is 6 sections over from
the Western edge of the grid square.
Therefore, the first three digits are
916.

23
Fourth and Fifth Digits

Now, to obtain the fifth and
sixth digits, do the same as
you did for the four digit
how far up from the
southern edge is the
church? To determine this,
picture the grid square as if
it was divided into ten equal
horizontal sections.

24
Six-digit Grid Reference

The church is 5 sections up
from the Southern edge.
Therefore, the last three
digits are 945.


In summary, the church is
located at 916945.

25
Questions

   Page 30, #1-10

   Page 33, Hamilton-Burlington Topographic
Map Study, #1, 2.

26

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