Practical Compass & Map Reading Skills. Map Reading & Navigation 1.Recap - Last Weeks Session...
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Transcript of Practical Compass & Map Reading Skills. Map Reading & Navigation 1.Recap - Last Weeks Session...
Practical Compass & Map Reading Skills
Map Reading & Navigation
1. Recap - Last Weeks Session • Preparatory Map Skills
2. The Ordinance Survey National Grid
3. Practical Compass & Map Reading Skills• The Compass• Practical Map Reading & Navigating
Recap on Last Weeks Session
Preparatory Map Skills• What is a map?• What are the Different Symbols?• Which Direction am I Going?• What is Scale?• What are Grid Lines & How do Grid References Work?• How do we Measure Distance?• How are Hills & Mountains Shown on Maps?
Recap on Last Weeks Session
The National GridConsists of a grid across the country that is
progressively broken down into smaller squares• The overall grid comprises into 5X5 500 Km
squares with each square defined by a single letter reference (A to Z).
• Each 500Km square is split into 5X5 100 Km squares with each square defined by a two letter reference.
• Each 100Km square is split into 100X100 1Km squares with each square defined by a four figure numeric map reference.
Compass Skills
What does a compass look like?
Compass Skills
1. True North– The notional direction of the North Pole
2. Grid North– Direction of the maps North / South grid lines. – Grid lines are exact 1 Km squares therefore N / S
grid lines across a map will not point to the same place.
– Not lines of longitude.
3. Magnetic North – The direction a compass needle will point. – It does not point to the North Pole but somewhere
north of Hudson Bay in Canada. – Magnetic north moving East by 1 deg every 6
years.
4. Magnetic Variation – The difference between grid North & magnetic
North at any point on the map. – This will vary depending on where you are.
North Points
Diagramatic Only
Grid
No
rth
Compass Skills
Step 1
Align the direction of travel arrow with the orienting arrow.
Step 2
Lay the compass on the map with direction arrow / orienting pointing to the top of the map with the long edge lined up with the North South grid Lines.
Step 3
Rotate the map & the compass together until the magnetic needle sits over the red orienting arrow.
The Map is Now Set
Setting a Map
Compass Skills
Taking a Bearing
•Step 1Find the two points on the map that you want to travel from and to. Line up your compass edge between the two points, so that your direction-of-travel arrow is pointing to your destination
•Step 1Find the two points on the map that you want to travel from and to. Line up your compass edge between the two points, so that your direction-of-travel arrow is pointing to your destination
Step 1
Line up your compass edge between the two points, so that your direction-of-travel arrow is pointing to your destination.
Step 2
Rotate the compass housing until the orienting lines in the centre are pointing to the top of your map
Step 3
Now read the bearing at the bottom of the direction-of-travel arrow, at the index line
Practical Map Reading & Navigating Skills
Key Map Reading Skills:
Transferring information gleaned from the map to the ground and vice
versa
• Locating your position from a map
• Determining a geographical direction & direction of travel
• Checking the direction of a path
• Identifying features in the countryside from a map
• Locating features marked on a map in the country side
Practical Map Reading & Navigating Skills
Navigating ToolsHandrails
Linear features you can follow, including paths, streams, ridges, walls etc.
Tick Features
Features that you pass or cross for example a bridge, farm buildings, ponds, boundary walls etc.
Catchments
Tick point where a decision has to be taken on direction, for example a path junction
Overshoots
Recognisable & distinct feature that indicates that you have gone beyond a catchment point.
Contour lines
The most important tool when navigating using a map. Can be used as tick features, catchments & overshoots.
Practical Map Reading & Navigating Skills
Route description:
• Cross bridge – 1
• Follow edge of enclosure – 2
• Head for the boulders – 3
• Follow top of escarpment – 4
• Ascend the ridge 5
• Reach trig point on summit - 6
Navigating Tools - Handrail & Tick Features
Practical Map Reading & Navigating Skills
Navigating a Route
• Split a route into legs
• Legs can be as short as a hundred metres or as long as several
kilometres – depending on terrain.
• For each leg convert map details into information that enable
you to navigate on the ground. A good way to do this is identify
five things about each leg.
‘The Five D’s’
Practical Map Reading & Navigating Skills
1. Destination – what will it look like when you reach the end.
2. Description – describe the leg using handrails & tick features.
3. Distance / Duration – how long will it take
– How do you measure distance on the ground?
4. Direction – in which direction do you need to walk.
5. Dangers – are there any navigational or physical dangers
enroute
Navigating a Route –The Five D’s
Practical Map Reading & Navigating Skills
Navigating a Route – Forming a Strategy• Before walking a leg map readers identify the 5 D’s.• The rest of the group are briefed on the relevant
information – usually limited to what you are going to see & when you will see it.
• At the end of the leg repeat the process & form a new strategy.
You must always have a strategy
At all times the entire team must know:• What you are expecting to pass, cross or see.• When are you are expecting to pass, cross or see it.