Lecture Leading Cadet Training Basic Navigation 4 Practical Navigation

Aids to Navigation Good navigators will not rely solely on accurate compass work & good distance measurement to find their way around. They will use a number of techniques to improve their navigation:

Aids to Navigation ROAMERS These are used to find a 6 figure grid reference more accurately than guess work.

ROAMERS Always read the nearest low figure (SW corner) Check that the roamer you are using is of the correct scale for the map. Aids to Navigation

RESECTION To find your physical location on a map, you will need THREE clearly visible landmarks. Take a compass bearing – deduct the magnetic variation – your position is somewhere along that line. Repeat for the other landmarks. Aids to Navigation

RESECTION Plot the three bearings onto your map. Draw a pencil line from each You are in the middle of the triangle where the 3 lines cross. Aids to Navigation

HANDRAILING You can use linear features of the landscape that form straight lines as a ‘path’. Like following the edge of a wood to the road. AABB

Aids to Navigation AIMING OFF Imagine that you are at point A and you want to cross the river at the bridge. If you aim directly for the footbridge, the chances are that you might miss it, and you wouldn’t know to turn upstream or downstream. AA BridgeBridge

Aids to Navigation AIMING OFF AA BridgeBridge Instead of aiming straight for the bridge, you should deliberately aim off slightly to one side. You would then know which way to turn when you hit the stream.

Aids to Navigation CONTOURING Going over the top of a hill (from A to B) may be shorter in distance, but remember ; for every 200m climb add 30mins to your journey time. It may be much easier to go around the hill, following the contours. BA

ATTACK POINTS Instead of taking a direct route from A to B, that might lead you off course. Aim for an easily identifiable feature that is close to your target – It increases the chances of reaching your objective. Aids to Navigation B A

DOG-LEG & BOXING AROUND Following your route may sometimes be difficult. There may be unexpected or unlooked for obstacles in your path. In cases like this making a Dog-Leg Detour, or Boxing Around can be good ideas. Aids to Navigation

DOG-LEG As you approach an obstacle, turn 45 o and walk an exact distance. Turn back 45 o and walk the same exact distance. Turn another 45 o and check the bearing, so that you are back on your original route. Aids to Navigation 100 m 100 paces 100 m 100 paces

Then turn another 90 o, and walk until Then turn another 90 o, and walk until the obstacle is cleared. Turn another 90 o and walk the same exact distance. Aids to Navigation 100 m 100 paces 100 m 100 paces Turn another 90 o and check the bearing, so that you are back on your original route. BOXING AROUND As you approach the obstacle, turn 90 o and walk an exact distance.

MAPPING SPIRAL An expanding series of 90 o turn walking legs which are multiples of the limit of visibility. It gives a wide search area, but can be extremely time consuming and inefficient. It is very useful however, if you are close to a known feature. Aids to Navigation

GLOBAL POSITIONING SYSTEM (GPS) GPS is a space-based satellite navigation system that provides location and time information in all weathers, anywhere on or near the Earth. Aids to Navigation Satellites are in known locations Four satellites are used to pinpoint locations GPS signals are blocked by mountains and buildings Accurate travel time for signals Each satellite is identified by a complex digital code Location pinpointed by correcting atmospheric signal delays

Although not actually part of Basic Navigation, Route Cards are an essential item for planning and confirming your expedition. and act as a safety net, should anything go wrong. Route Cards

Check of Understanding What is the six figure grid reference shown on the roamer?

Check of Understanding If you wanted to find your position on a map using prominent features in vision, what would give the best result? Three bearings that cross to give a small triangular fix. Three bearings that cross to give a large triangular fix. One exact bearing to give a line fix. Two bearings that cross to give a position fix.

Check of Understanding Following linear features to guide you to your destination is known as what? Using Attack Points Aiming Off Handrailing Contouring

Check of Understanding When making a dog-leg detour at what angle should you make your turns? 90 o 25 o 60 o 45 o

Check of Understanding What is meant by contouring? Walking up a hill Walking around a hill Walking down a hill Walking over a hill

Check of Understanding What is making an expanding series of 90 o turn walking legs known as? Boxing around Aiming off Mapping spiral Attack points

Check of Understanding Instead of taking a direct bearing you deliberately veer to the left or right to hit an obvious feature, what is this known as? Boxing around Contouring Dog-leg Attack points

Leading Cadet Training Basic Navigation End of Presentation