Presentation on theme: "Map Reading & Navigation"— Presentation transcript:
1Map Reading & Navigation Prepared by: The Expedition Company Limited
2IntroductionThis clear and simple tool is designed to provide you with the basic skills with which to learn to map read.Using a step by step process, you can progress comfortably at your own pace, with practical exercises and illustrations in every section to help you learn.Prepared by: The Expedition Company Limited
3Equipment requirements are simple. You will need a:Ordnance Survey MapSilva CompassSharp pencilPlain PaperFine StringPrepared by: The Expedition Company Limited
4Course Content Route Planning & Safety The Compass Maps Components NorthTrueGridMagneticMap & compass workMapsA brief HistoryComponentsType/ScaleSymbolsPlotting a locationMeasuring distanceReliefRoute Planning & SafetyPrepared by: The Expedition Company Limited
5DefinitionMap .noun. Flat representation of the earth or some part of it with its physical or political features or of the heavensPrepared by: The Expedition Company Limited
6HistoryEver since man has been able to write and draw there is evidence to also show that he has recorded routes on land and sea.Where maps were originally shown on clay tablets and papyrus, we can now display them on paper and even CD Rom!Prepared by: The Expedition Company Limited
7The Ordnance Survey Map Ordnance Survey maps come in a variety of different formats and this guide will show you how to choose which one is best suited for your own use.Prepared by: The Expedition Company Limited
8Types of Map The importance of choosing the right map. Prepared by: The Expedition Company Limited
9SymbolsWe interpret both man made and natural features on the map, through a system of symbols.Every Ordnance Survey map has a key showing the definition of each symbol to help you. We will look at a few of the more common symbols.Prepared by: The Expedition Company Limited
10Symbol examplesPrepared by: The Expedition Company Limited
11Symbol examplesPrepared by: The Expedition Company Limited
12Grid lines Every Ordnance Survey map is covered in a series of grids. By learning to use these grids we are able to locate a particular point on a map.Prepared by: The Expedition Company Limited
13DistanceGrid lines on all Ordnance Survey Maps are spaced 1km apart, regardless of scale.This makes it easy to judge the rough distance between points by counting squares.1.5 km1 kmPrepared by: The Expedition Company Limited
15Reading a Grid Reference Grid references should be read in the following order:Eastings - Along the CorridorNorthings - Up the StairsPrepared by: The Expedition Company Limited
16Plotting a Grid Square5252636465665151StairsThe5050& UpAlong the Corridor496263646566
17Plotting a Grid Square5252636465665151Grid: 64 505050496263646566
18Accurate PlottingHaving plotted the grid Square (1km x 1km) you will often need to establish the accurate location of a point or feature within the Square.This is achieved by dividing the square into a further ten Eastings (Vertical lines) & Northings (Horizontal lines).These additional lines are read in exactly the same manner as before.Prepared by: The Expedition Company Limited
20Plotting an accurate location 100 metre accuracy 626364656652Grid:515049
21Measuring DistanceBy using the scale at the bottom of each Ordnance Survey Map you can easily convert a measurement in centimetres into a real distance on the ground.Prepared by: The Expedition Company Limited
22Measuring Distance using a Silva Compass Nearly all compasses have a centimetre scale which proves an effective tool for measuring the distance between two points.Prepared by: The Expedition Company Limited
23Measuring Distance using a Piece of String Trace your route on the map with a piece of string and mark the points at which the route starts and finishes on the string.Place the string against the scale on the map and read off the equivalent distance on the ground.Prepared by: The Expedition Company Limited
24Measuring Distance using a Map Measurer Map measurers are purposefully designed for measuring distances on a map.Trace your route with the small wheel at the bottom of the measurer and it will automatically tell you the distance on the ground via a rotating scale.Prepared by: The Expedition Company Limited
25Relief Relief refers to the way in which height is displayed on a map. This is shown by a system of lines called ‘Contours’.Prepared by: The Expedition Company Limited
26Contour LinesContour lines link points of equal height on the map at ten metre intervals.Contours display how many metres land is above sea level.Prepared by: The Expedition Company Limited
27DefinitionCompass .noun. Instrument showing user the direction of north and other points of the ~ by means of magnetic needlePrepared by: The Expedition Company Limited
28The CompassThere are a variety of different compass styles available to you. We suggest that to begin with, you use a Silva compass similar to the one pictured here.Prepared by: The Expedition Company Limited
29The CompassThey were originally discovered by the Chinese 5000 years ago.They are made in a variety of forms for use on land, above and below the sea and in the air.Examples of activities in which they are used are:Hillwalking - MountaineeringCycling - SurveyingDriving - MilitarySailing - Scuba DivingFlying - OrienteeringPrepared by: The Expedition Company Limited
30Cardinal Points (Compass Points) North0º & 360ºNorth West : 315ºNorth East : 45ºWest270º90ºEastSouth West : 225ºSouth East : 135º180ºPrepared by: The Expedition Company LimitedSouth
31Bearings are taken in degreesº- The cardinal points are divided up into 360º & measured clockwise. North0º & 360ºNorth West : 315ºNorth East : 45ºWest270º90ºEastSouth West : 225ºSouth East : 135º180ºPrepared by: The Expedition Company LimitedSouth
32Parts of the CompassThe compass can be broken down into various components.We will look at each component separately to define its use.Prepared by: The Expedition Company Limited
33Base Plate & Compass Housing The Base Plate is the mounting for the housing and displays a variety of information eg. Scale ruler.The Compass Housing contains a magnetic bar, called the Needle and defines the points of the compass on a rotating bezel.Compass HousingBase PlatePrepared by: The Expedition Company Limited
34The Compass NeedleThe needle is suspended in liquid which enables it to move freely, always settling with the red end pointing North.Some needles are Luminous to help navigation in the dark.NeedlePrepared by: The Expedition Company Limited
35Direction of Travel Arrow The Direction of Travel Arrow indicates the direction along which you wish to travel or take a bearing.The arrow is fixed within the base plate.The sides of the base plate run parallel to the arrow.Direction of Travel ArrowPrepared by: The Expedition Company Limited
36The Index LineThe Index Line is a fixed line within the Compass Housing and is in line with the direction of travel arrow.The Index Line marks the bearing you set by rotating the bezel.Index LinePrepared by: The Expedition Company Limited
37Orienting LinesThese are displayed within the rotating Compass Housing and are designed to be aligned parallel with the Eastings on a map.The orienting lines on some compass models show one half of the lines in red to depict north.Orienting LinesPrepared by: The Expedition Company Limited
38Compass ScaleNearly all compasses have a centimetre scale along the edge of the base plate to enable you to measure distances.Used in conjunction with the scale at the bottom of the map, the compass scale enables you to calculate the distance on the ground.Compass ScalePrepared by: The Expedition Company Limited
39Points to NoteStand clear of metal objects when using the compass. They will cause the needle to deviate and create inaccurate bearings. Objects as small as watches can make a difference.Hold the compass as flat as possible to allow the needle to move freely.Look after your compass - try to avoid dropping or knocking it.Store away from other compasses and electrical equipment.Your compass may need replacing if a large air bubble forms in the Compass Housing.Prepared by: The Expedition Company Limited
40True / Grid / Magnetic North True North and South are at the geographical poles.Grid North is the direction to which all Ordnance Survey Maps are oriented. We take our map bearings using Grid North.Magnetic North is the direction a compass points to and in the UK it is located approximately 5º West of Grid North.
41Magnetic VariationTrue NorthThe difference in degrees between Magnetic (Mag) North and Grid North is referred to as the Magnetic Variation (usually 5º West in UK.)Grid NorthMagnetic North5º
42Magnetic VariationTrue NorthIt is important to understand the relationship between Grid & Mag north as this will become important when we start to convert bearings to and from a map.Grid NorthMagnetic North5º
43Map & Compass WorkHaving looked separately at both the Ordnance Survey Map & Silva Compass the following example will demonstrate how they are used together.If you are unsure about anything which has been covered in the previous slides, look back now before you progress to the next section.
44Map & Compass WorkWhen working from the map we deal with Grid Bearings.When following a compass on the ground we work with Magnetic Bearings.There is a simple system which enables us to convert Grid to Mag and Mag to Grid.The system refers to whether we add or subtract the magnetic variation to convert the bearing.
45Map & Compass Work Mag to Grid…………. GET RID Grid to Mag………….ADD (usually 5º West in UK)
47Map to Ground Select a start and finish point on the map. Line up the edge of the compass with the line along which you intend to travel.Keeping the base plate static - rotate the compass housing until the orienting lines are parallel with the Eastings and the red ‘N’ is pointing to North on your map.
48Map to GroundRead the bearing shown on the housing from the index line.Remember - Grid to Mag……Add.Add the magnetic variation shown at the top of the map (usually 5º West in UK.)You now have your magnetic bearing of the course you have chosen. The next step is to orientate yourself.
49Orientating Hold your compass level and steady. Turn your body until the red end of the needle is in line with the Red ‘N’ on the Housing.The direction of travel arrow is now pointing along the route you chose from the map and you are ready to travel.
50Following the Compass Bearing Hold your compass level and steady.Ensure that the red end of the needle is in line with the Red ‘N’ on the Housing every time you refer to the compass bearing.Follow the direction of travel arrow. You will find it easier to line up the direction arrow with a physical feature on the ground (eg tree, pylon, tower). Use this as a reference point which you can move towards. This is easier than following the compass every inch of the way.
52Ground to MapSelect the feature on the ground to which you wish to take a bearing.Hold the compass steady and level.Point the direction of travel arrow at the feature.Rotate the housing until the red end of the needle is in line with the Red ‘N’ on the Housing.
53Ground to MapThis is your Mag bearing which you can either travel along or convert to a grid bearing.To plot on the map you should first locate your own position and mark it.Convert the Mag bearing to a Grid bearing by Mag to Grid……Get Rid. (Usually 5º West in UK.)Subtract the magnetic variation.
54Ground to MapPlace the compass on the map and keeping the bearing set on the housing, rotate the whole compass until the orienting lines are parallel to the Eastings on the map. The edge of the compass should run through your position and show the bearing on the map.
55Ground to MapBy turning your body until the red end of the needle is in line with the Red ‘N’ on the Housing you have now oriented yourself and the map.
56You and your map are now facing North. Quick OrientationYou can orientate yourself and the map to the ground at any time using this easy system:A. Lay the compass on the map.B. Line the edge of the compass and the orienting lines up with the Eastings.C. Turn your body until the red end of the needle is in line with the Red ‘N’ on the Housing.You and your map are now facing North.
57Route PlanningIt is important, where possible, to take time in planning your route before you start.This will help you to identify any problems early and to estimate how far you intend to travel and how long it should take.Prepared by: The Expedition Company Limited
58Route CardA route card is simple to produce and makes navigation on the ground simple. A basic format is shown here:Prepared by: The Expedition Company Limited
59Route Planning & Safety Make sure that your route is well within your ability and that you are in possession of the right equipment.Leave a copy of your route card with a friend or contact in order that you can be easily found in an emergency.Prepared by: The Expedition Company Limited
60Map Reading & Navigation Prepared by: The Expedition Company Limited
61Ordnance Survey Romsey Road SOUTHAMPTON United Kingdom, SO16 4GU
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