Triangulation plain

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A bare bone ppt on Triangulation

oldschoolyard.com

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Triangulation plain

  1. 1. Triangulation:to locate yourself on a map by comparing yourtopographic map to what you are looking at, andidentifying terrain features that you are sure youcan recognise for real and on the map
  2. 2. Position Fixing – Triangulation or Resection1. Used when you’re unable to fix your position2. Find 3 prominent features3. Take a magnetic bearing of the features4. Convert these to a grid bearing5. Change to a back bearing6. Plot all bearings on map7. Your position is where the back bearings intersect.
  3. 3. FeaturesMagnetic bearingsGrid bearingsBack bearingsDraw bearings on your mapTriangle of Error (GR)
  4. 4. FindingMyselfGoesBetterDrawingTriangles
  5. 5. Features• Identify Three easily recognisable features that you can see in real life and on the map• The further apart the 3 features the better• for each feature, it helps if there is an exact point you can take a bearing off
  6. 6. Magnetic Bearings• Your bearings must be taken as precisely as possible from each feature• Using an exact point like a cliff edge or mountain peak helps to maintain accuracy
  7. 7. Grid Bearings• find the Magnetic Variation for your area• Usually subtract this number from your Magnetic Bearings to create Grid Bearings (for each bearing!)• GMAMGS when Mag North is West of True North (like it is for us in SW WA)
  8. 8. Back Bearings• Create a back bearing by finding the exact opposite direction (in degrees) of you Grid Bearings (do this for each grid bearing)
  9. 9. Drawing the Back Bearings• As accurately as possible draw a line on your topographical map along the back bearing (for each back bearing)• Make sure you start the line at the point your compass originally aimed at
  10. 10. Triangle of Error• You should be left with three lines that intersect in a triangle• This is the Triangle of Error and you now know your position is within this triangle!• Give a 6 digit GR for your final answer All images sourced from Google image search and are used for education purposes only

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