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
Half way between
North and West
270o
N
NW
NE
W
Half way between
North and East
E
SW
Half way between
South and West
090o
SE
Half way between
South and East
S
180o
7
.
Bearings
360/000o
N
1. Measured from North.
2. In a clockwise direction.
060o
270o
60o
W
090o
E
3. Written as 3 figures.
S
180o
N
W
145o
S
N
N
E
145o
W
230o
230o
S
315o
E
W
E
315o
S
8
A 360o
protractor is
used to measure
bearings.
315o
Bearings
360/000o
350o
N
020o
NW
Use your protractor to
measure the bearing of
each point from the
centre of the circle.
(Worksheet 1)
045o
NE
290o
270o
080o
W
E
250o
090o
110o
SW
225o
SE
210o
S
180o
160o
135o
9
N
360/000o
030o
330o
045o
315o
290o
075o
090o E
W 270o
Control
Tower
Estimate the
bearing of
each aircraft
from the
centre of the
radar screen.
110o
250o
Air Traffic
Controller
135o
225o
170o
200o
8-Apr-15
180o
S
10
N
360/000o
7
325o
010o
8
310o
040o
1
ACE
060o
Controller
11
contest
12
4
280o
2
Estimate the
bearing of
each aircraft
from the
centre of the
radar screen.
090o E
W 270o
3
Control
Tower
250o
235o
9
120o
Air Traffic
Controller
6
195o
8-Apr-15
5
10
180o
S
155o
Worksheet 2
11
Bearings
Measuring the bearing of one point from another.
N
To Find the bearing of Q from P.
P
1. Draw a straight line between both points.
118o
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
Thankyou
Airfield (B)
306.7 MHZ UHF
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
digit method. Then ask yourself,
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
method and ask yourself,
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