Navigation Basic to Advanced Navigation What is navigation? –noun 1. the act or process of navigating 2. the art or science of plotting, ascertaining,

Présentation au sujet: "Navigation Basic to Advanced Navigation What is navigation? –noun 1. the act or process of navigating 2. the art or science of plotting, ascertaining,"— Transcription de la présentation:

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2 Navigation Basic to Advanced Navigation

3 What is navigation? –noun 1. the act or process of navigating 2. the art or science of plotting, ascertaining, or directing the course of a journey

4 Essentially … Navigation is about route finding. It can appear complicated but is actually very simple. Good navigators will ask themselves three questions…. 1. Where am I? (Position fixing) 2. Where am I going to? (Direction finding) 3. How do I get there?

5 The navigators toolbox There are various techniques and tools which can be utilised to aid navigation. A good navigator needs to know which tool to use in a particular situation

6 The navigators toolbox A solid understanding of maps Scale, colour, contours, grid lines and conventional signs Compasses, compass bearings and back bearings Aiming off, handrails, attack points

7 Maps A map is a two dimensional representation of a three dimensional geographic area

8 The process of map making 1) Aerial photographs are first taken of a given area by aircraft 2) These images are then reproduced manually by cartographers

9 Maps Colour It is frequently necessary to get a fast overview of a given area and the colours used on maps give an indication as to the type of terrain and relief of the land Water Vegetation Areas of high altitude

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11 Maps Shapes All 3 dimensional features in our environment have some form or shape which can be represented by a map. Different features have different shapes however there are some generalisations we can make: Man made features are generally regular Natural features are generally irregular

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13 Scale

14 Scales and ratios 1:50,0001:25,000 1cm on the map is equivalent to 50,000cm on the ground 1cm on the map is equivalent to 25,000cm on the ground

15 Scale continued…. Different scales on maps are useful for different purposes 1:50,000 maps are useful for…. Route planning Route overviews 1:25,000 maps are useful for…. Detailed information Wild country

16 Grid lines Grid lines are laid over all Ordnance Survey maps and are an aid to help locate features Vertical grid lines are called….Northings Horizontal grid lines are called….Eastings Northings and Eastings enable us to do grid references (4 and 6 figure)

17 Problem… The terrain is three dimensional and maps are two dimensional So how do cartographers represent relief (peaks and troughs in the land) on a 2 dimensional map? Contour Lines, spaced at 10m intervals Thus, land can rise up to 9.5m above sea level without being represented by a contour line!

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20 Calculating time A key feature of route planning is the ability to accurately calculate the time required for any given journey This is calculated by a simple formula: Naismith’s Rule: “4km / hour or 1km / 15 minutes + 1 minute for every contour line”

21 Conventional signs Conventional signs or map symbols perform the same function as icons on a computers desktop They are a fast and effective way of depicting a particular feature, either manmade or natural

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25 The compass A navigational tool that does far more than tell you the direction of north! Compasses can be used to take bearings which are used when visibility is minimal or to confirm the direction of travel

26 Compass architecture Transparent baseplate Compass housing Roamer Direction of travel arrow

27 Compass bearings Align the edge of the compass with the start and end point Rotate the compass housing until the orienting arrow and lines point N on the map Account for magnetic deviation Rotate the map and compass together until the red end of the compass needle points north Follow the direction of travel arrow

28 The toolbox so far… We now have a navigational toolbox containing some useful tools to facilitate navigation Maps, colour, shape, scale, grid references, contours, geographical features The compass, compass architecture and compass bearings

29 A few additional tools Handrails Aiming off Attack points

30 Handrails What is a handrail? A handrail is a linear geographic feature such as a river, stream, fence or ridge What is ‘handrailing?’ Handrailing is where a handrail is used as a point of reference and hikers walk along a handrail for part of their journey

31 A very obvious natural handrail! The arête of Helvellyn formed from glacial erosion

32 Minor Road Stream Coniferous Wood Using natural, linear handrails

33 Aiming off Aiming off is used when walking on a bearing You should perform a compass bearing and aim towards a geographical feature that lies on the bearing When that feature has been reached another bearing can be taken

34 Attack points The geographic feature which you are aiming for is called an ‘attack point’ Linear feature Attack point Compass bearing Aiming off

35 What makes a successful navigator? Where am I? (Position fixing) Where am I going to? (Direction finding) How do I get there? Or, “What tools do I have in my navigational toolbox to enable me to reach the required destination”

36 Position fixing Setting the map using colour, symbols, geographic features etc Grid references Aiming off Compass bearings Destination Attack Point Handrailing Putting it all together

37 That’s all folks! More help? ‘Mountain Navigation,’ Peter Cliff (1991)