Map Reading Direction Direction refers to the relative

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. plk 83. 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) • North, south, east and west are the four cardinal (主要/基本的) points. • Subdivide into 12 more points. • There a total of 16 points as shown below. 北 NNW N NNE NE NW ENE WNW 西 W E WSW SW ESE SSW SE S 南 SSE 東

Compass Point (羅盤方位) • All points are shown in directional points only. • All points are divided equally, so we can know its degrees. 22. 5 o 0º 315º N NNW NE NW ENE WNW 270 º 45º NNE W E WSW SW ESE SSW 225º 90 º SE S SSE 180 º 135º

“Compass Points” Game N NE E W S 69 68 SE SW 71 70 NW 67 66 65 64 12 13 14 15 16 17 18 19 20 21 22

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 NE 1 step.

“Compass Points” Game 71 70 Where is the treasure? 69 68 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. 67 66 65 64 12 13 14 15 16 17 18 19 20 21 22

Whole Circle Bearing (方位角) • More accurately, we can use whole circle bearing. • The compass is divided into 360 o counting clockwise from the 順時針方向 north. N 360 º Here is one more example. N W E E S 225º S

Reduced Bearing (象限角) • 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. N W E S S 45ºE 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 “S 45 º E”.

Let’s have some more examples. . . N W N N 45ºE E W S 45 ºW S N 45 ºW N W S Remember, Reduced Bearing never starts with “E” or “W” ! E S E

Let’s do a simple exercise first.

N The direction of Point A from Point B is. . . A. Northwest A B. Southeast B C. West D. South The Reduced Bearing of Point X from Point Y is. . . A. N 45º E N B. S 45º N N C. S 45º W D. W 45º S X Y

Conversion from one to another measuring direction method 045 o N 45 o. E 315 o N 45 o. W

YOU ARE VERY SMART!

Sorry, please try again!

Conclusion • Which three methods have we learned today? E. g. SW, NNE E. g. 360 o, 090 o E. g. S 71 o. E, N 45 o. W - Compass points - Whole circle bearing - Reduced bearing

Let’s do exercise!