map reading - direction

Map Reading - Direction

Direction

• refers to the relative ( 相對的 ) position ( 位置 ) between two points measures with a compass ( 羅盤 / 指南針 ) and expressed in terms of compass readings.

• There are 3 ways to measure the direction.

Which are these three ways?

• (1) Compass Points• (2) Whole Circle Bearing• (3) Reduced Bearing

How many directions do you know?

http://www.plk83.edu.hk/ckf/

Direction names in English東北 , 東南 , 西北 , 西南

Can you write the directions on the blackboard?

Compass Point ( 羅盤方位 )

N

E

S

W

NNENE

ENE

ESESE

SSESSWSW

WSW

WNW

NWNNW

•North, south, east and west are the four cardinal ( 主要 / 基本的 ) points. •Subdivide into 12 more points. •There are a total of 16 points as shown below.

東

南

西

北

Compass Point (羅盤方位 )

N

E

S

W

NNENE

ENE

ESESE

SSESSWSW

WSW

WNW

NWNNW

0º

90 º

180 º

270 º

45º

135º225º

315º

•All points are shown in directional points only. •All points are divided equally, so we can know its degrees.

22.5o

Teacher Desk

Terry Simon Apple KenChing Pinky Steve

Chris Ann TonyWong Ron Katrina Yuki Terence

Sally Tim Victoria Jacky Herman King Ceci

ThomasWongHingYing

Tse KaFai Sharon Janice

Lo Fish KenWong

StevenWong

Ming JennieLeung Yu

ChengKaHei

Horal StephenLam

Jammi Gary TonyYiu Priscilla Janice

ChanKelvinWong

12 13 14 15 16 17 18 19 20 21 22

71 70 69 68 67 66 65 64

“Compass Points” Game

W

N

NE

E

SSESW

NW

Where is the treasure?• Start from 1266.• Go to the north 1 step.• Go to the east 2 steps.• Go to the south 1 step.• Go to the SE 1 step.• Go to the NE 2 steps.• Go to the NW 2 steps.• Go to the East 3 steps.• Go to the SE 2 steps.• Go to the NE1 step.

Teacher Desk

Terry Simon Apple KenChing Pinky Steve

Chris Ann TonyWong Ron Katrina Yuki Terence

Sally Tim Victoria Jacky Herman King Ceci

ThomasWongHingYing

Tse KaFai Sharon Janice

Lo Fish KenWong

StevenWong

Ming JennieLeung Yu

ChengKaHei

Horal StephenLam

Jammi Gary TonyYiu Priscilla Janice

ChanKelvinWong

12 13 14 15 16 17 18 19 20 21 22

71 70 69 68 67 66 65 64

“Compass Points” Game

1. Start from 1266.2. To the north 1 step.3. To the east 2 steps.4. To the south 1 step.5. To the SE 1 step.6. To the NE 2 steps.7. To the NW 2 steps.8. To the East 3 steps.9. To the SE 2 steps.10. To the NE 1 step.

Where is the treasure?

N

E

S

W

Whole Circle Bearing (方位角 )•More accurately, we can use whole circle bearing.•The compass is divided into 360o counting clockwise from the north.

360 ºHere is one more example.

N

E

S

225º

順時針方向

Reduced Bearing (象限角 )

N

E

S

W

•It is shown by both the directional points (N,E,S and W) and degree. •The compass is divided into 4 parts. The direction is read either from the North or the South, but not at the East and West. Therefore, compass bearing can never be greater than 90 º.

S45ºE

How to determine whether we should use “N” or “S”? It depends on the point we measure is closer to N or S. In the figure on the left, the point we measure is closer to the South, so we start from the South and have the reduced bearing “S45 º E”.

Let’s have some more examples...N

E

S

W

N

E

S

W

N

E

S

W

N45ºE

S45 ºW

N45 ºW Remember, Reduced Bearing never starts with “E” or “W” !

Let’s do a simple exercise first.

A

B

The direction of Point A from Point B is...N

A. Northwest

B. Southeast

C. West

D. SouthThe Reduced Bearing of Point X from Point Y is...

A. N45º E

B. S45º N

C. S45º W

D. W45º S X

YN

N

Compasspoint

Wholecirclebearing

Reducedbearing

NE

NW

045o N45oE

315o N45oW

Conversion from one to another measuring direction method

YOU ARE VERY SMART!

Sorry, please try again!

Conclusion

• Which three methods have we learned today?

E.g. SW, NW, NNE - Compass points

E.g. S71oE, N45oW

- Whole circle bearingE.g. 360o, 090o

- Reduced bearing

Let’s do exercise!