Locating Places on a Locating Places on a MapMap

22

Cardinal PointsCardinal Points The four main directions of The four main directions of

a compass are known as a compass are known as cardinal pointscardinal points.  They are .  They are north (N), east (E), south north (N), east (E), south (S) and west (W). (S) and west (W). 

33

Intercardinal (Ordinal) PointsIntercardinal (Ordinal) Points

Sometimes, the Sometimes, the intercardinal intercardinal (ordinal) (ordinal) points of:points of:• north-east (NE),north-east (NE),• north-west (NW),north-west (NW),• south-east (SE) andsouth-east (SE) and• south-west (SW) south-west (SW)

are shown on the are shown on the compass.compass.

44

Compass BearingsCompass Bearings ThisThis compass shows compass shows

degree degree measurements from measurements from 0° to 360° in 10° 0° to 360° in 10° intervals with:intervals with:• north representing 0° north representing 0°

or 360° or 360° • east representing 90° east representing 90° • south representing south representing

180° 180° • west representing west representing

270° 270°

55

BearingBearing The The true bearingtrue bearing to a to a

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

66

Bearing ExampleBearing Example For example, the For example, the

bearing of point bearing of point P P is is 065º which is the 065º which is the number of degrees in number of degrees in the angle measured in the angle measured in a clockwise direction a clockwise direction from the north line to from the north line to the line joining the the line joining the centre of the compass centre of the compass at at OO with the point with the point P P (i.e. (i.e. OPOP).).

77

.

Compass Points

N

S

EW 090o

360/000o

270o

180o

SE

Half way between South and East

SW

Half way between South

and West

Half way between North

and WestNW NE

Half way between North

and East

88

1. Measured from North.2. In a clockwise direction.3. Written as 3 figures.

N

S

EW

N

S

EW

N

S

EW

060o

145o230o

315o

60o

145o

230o 315o

Bearings

N

S

EW 090o

360/000o

270o

180o

99

Bearings

N

S

EW 090o

360/000o

270o

180o

A 360o protractor is

used to measure bearings.

020o

080o

110o

SE

135o160o210o

SW

225o

250o

290o

NW

315o 350o

Use your protractor to measure the bearing of each point from the centre of the circle. (Worksheet 1)NE

045o

1010

19 Apr 2023

360/000o

090o

180o

270oW E

N

S

Air Traffic

Controller

Control Tower

Estimate the

bearing of each

aircraft from the centre of the radar screen.

030o

075o

045o

200o

135o

330o

225o

290o

110o250o

315o

170o

1111

19 Apr 2023

360/000o

090o

180o

270oW E

N

S

Air Traffic

Controller

Control Tower

1

2

12

109

8

411

7

6

53

040o

250o

280o

120o

195o

010o

325o

155o

235o

310o

060o

Worksheet 2

Estimate the

bearing of each

aircraft from the centre of the radar screen.

ACE

Controller

contest

1212

Bearings

Measuring the bearing of one point from another.

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

3. Measure angle between.

N

P

Q

To Find the bearing of Q from P.

118o

1313

Bearings

Measuring the bearing of one point from another.

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

3. Measure angle between.

N

P

Q

To Find the bearing of P from Q.

298o

1414

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

Airfield (B)

306.7 MHZ UHFThankyou

170o

255o

1515

Bearings

N

S

EW 090o

000/360o

270o

180o

1616

Grid SystemsGrid Systems The most common way to locate a place on a The most common way to locate a place on a

map is to use a grid system.map is to use a grid system.

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

1717

Simple Grid SystemSimple Grid System A simple grid is shown with the location of a point of A simple grid is shown with the location of a point of

interest that we want to describeinterest that we want to describe

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

1818

Alphanumeric GridAlphanumeric Grid An alphanumeric grid An alphanumeric grid

uses letters and numerals uses letters and numerals to identify squares on a to identify squares on a grid pattern.grid pattern.

1919

Map Grid (Military Grid)Map Grid (Military Grid)

A method to locate points on a mapA method to locate points on a map

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

2020

Using the Military GridUsing the Military Grid For instance, let's For instance, let's

utilize the military grid utilize the military grid to determine which to determine which grid square the church grid square the church is located inis located in..

2121

Identifying Grid Squares - Identifying Grid Squares - EastingEasting

First, gFirst, go to the Western o to the Western edge of the grid square that edge of the grid square that the object is in first. Then the object is in first. Then from that western edge, go from that western edge, go up or down until you come up or down until you come to a number. In this case, to a number. In this case, going up or down yields the going up or down yields the number number 9191. These are the . These are the first two digits for the square first two digits for the square that the church is in.that the church is in.

2222

Identifying Grid Squares - Identifying Grid Squares - NorthingNorthing

Secondly, go to the Secondly, go to the Southern edge of the grid Southern edge of the grid square that the object is in. square that the object is in. From that southern edge, From that southern edge, go across until you come to go across until you come to a number. In this case, the a number. In this case, the number is number is 9494. This . This represents the third and represents the third and fourth digits for the square fourth digits for the square that the church is in.that the church is in.

Hence, the church is in Hence, the church is in grid square 9194grid square 9194

2323

Six Digit Military Grid MethodSix Digit Military Grid Method

With this method, you start out With this method, you start out exactly the same way as the four exactly the same way as the four digit method. Then ask yourself, digit method. Then ask yourself, how far over from that western edge how far over from that western edge is the church? To determine this, is the church? To determine this, picture the grid square as if it was picture the grid square as if it was divided into ten equal vertical divided into ten equal vertical sections.sections.

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

2424

Fourth and Fifth DigitsFourth and Fifth Digits Now, to obtain the fNow, to obtain the fifth and ifth and

sixth sixth digits, do the same as digits, do the same as you did for the four digit you did for the four digit methodmethod and and ask yourself, ask yourself, how far up from the how far up from the southern edge is the southern edge is the church? To determine this, church? To determine this, picture the grid square as if picture the grid square as if it was divided into ten equal it was divided into ten equal horizontal sections.horizontal sections.

2525

Six-digit Grid ReferenceSix-digit Grid Reference The church is 5 sections up The church is 5 sections up

from the Southern edge. from the Southern edge. Therefore, the last three Therefore, the last three digits are 945.digits are 945.

In summary, the church is In summary, the church is located at located at 916945916945..

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QuestionsQuestions

Page 30, #1-10 Page 30, #1-10

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