map reading - direction
Post on 08-Jan-2018
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DESCRIPTIONDirection 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.
Map Reading - Direction Direction refers to the relative () position () between two points measures with a compass (/) 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? Video Show Direction names in English
, ,, Can you write the directions on the blackboard? Compass Point () North, south, east and west are the four cardinal (/) points. Subdivide into 12 more points. There are a total of 16 points as shown below. N NNW NNE NE NW ENE WNW W E WSW ESE SW SE SSW SSE S Compass Point () All points are shown in directional points only.
All points are divided equally, so we can know its degrees. 22.5o 0 315 N 45 NNW NNE NE NW ENE WNW 270 W E 90 WSW ESE SW SE SSW SSE S 135 225 180 Compass Points Game N 71 70 69 68 67 66 65 64 W S E
NE E S SE SW NW W 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. Compass Points Game Where is the treasure? 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. Whole Circle Bearing ()
More accurately, we can use whole circle bearing. The compass is divided into 360o counting clockwise from the north. N 360 Here is one more example. N W E E S 225 S Reduced Bearing () 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 . How to determine whether we should use N or S? Itdepends 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 E. N W E S45E S Lets have some more examples...
N N N45E W E W E S45 W S S N Remember, Reduced Bearing never starts with E orW ! N45 W W E S Lets do a simple exercise first. The direction of Point A from Point B is...
A. Northwest B. Southeast C. West D. South A B The Reduced Bearing of Point X from Point Y is... A. N45 E B. S45 N C. S45 W D. W45 S N Y N X Conversion from one to another measuring direction method
N45oE 045o N45oW 315o 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.360o, 090o - Whole circle bearing E.g.S71oE, N45oW - Reduced bearing Lets do exercise!