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Map Reading III Reading a Grid & Determining Direction

Map Reading III Reading a Grid & Determining Direction. GRC JROTC COL. ALEXANDER. Purpose North (3 types) Types of Azimuths Measuring Azimuths. Plotting Azimuths Practical Exercise Summary Conclusion. Outline . Purpose.

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Map Reading III Reading a Grid & Determining Direction

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  1. Map Reading IIIReading a Grid &Determining Direction GRC JROTC COL. ALEXANDER Map Reading II

  2. Purpose North (3 types) Types of Azimuths Measuring Azimuths Plotting Azimuths Practical Exercise Summary Conclusion Outline Map Reading III

  3. Purpose To lay the groundwork for successful map reading and land navigation by exposing the cadet to determining grid and magnetic azimuths using a protractor and compass. Map Reading III

  4. North (x3 types) • True North- line through North Pole. • Magnetic North- direction to northern magnetic pole (compass). • Grid North-North as established by map maker. Magnetic North Grid North True North Map Reading III

  5. Types of Azimuth An azimuth is an angle measured clockwise from a base line direction (north). • Grid- angle between grid north and a straight line plotted between two points on a map. • Magnetic- angle determined by using a compass. • Back- opposite direction of an azimuth. Map Reading III

  6. Measuring an Azimuth N • Protractors • Compasses E W S 360 degrees in a CIRCLE Map Reading III

  7. Measuring an AzimuthProtractors Map Reading III

  8. Measuring an AzimuthCompasses Magnetic Lensatic Compass (Military Type) Silva Polaris Compass (Civilian Orienteering) Map Reading III

  9. 3 Ways to Plot Azimuths • Plotting Azimuths between 2 points on a map. • ConvertingMagnetic Azimuths to Grid Azimuths. • ConvertingGrid Azimuths to Magnetic Azimuths. Map Reading III

  10. Reading a GRID 10-DIGIT GRID: EG 1 2 3 4 5 6 7 8 9 10 1000M 100M 10M 1M 1000M 100M 10M 1M 8-DIGIT GRID: EG 1 2 3 4 5 6 7 8 1000M 100M 10M 1000M 100M 10M Map Reading III

  11. Reading a GRID 08 74 (4 digit) 084 742 (6 digit) Square Identification Grid Zone 8-Digit Grid (w/in 10 M) COLUMBUS: 16S FL (or GL) 08 45 74 25 TENINO: 10T EH (or EG) 15 85 82 20 Map Reading III

  12. Reading a GRID 76 75 28 28 1000 METERS 1000 METERS 2. Then UP 1. Read RIGHT 27 27 76 75 Map Reading III

  13. Using a Protractor MAKE SURE THAT YOU USE THE CORRECT SCALE for the MAP you have 1:50,000 Map Reading III

  14. Using & Reading a Protractor 25 or 250 M 1 “GRID SQUARE” = 1000 M x 1000 M Each # (1, 2, 3, etc) = 100 METERS Each | in between = 50 METERS Map Reading III

  15. Slide protractor over to the RIGHT - 45 Reading a Protractor Line-Up Vertical Scale of protractor with 08 Grid 09 08 Move UP 25 & place a dot or mark 75 75 RIGHT UP 74 74 08 45 74 25 Use Protractor 08 09 Map Reading III

  16. MUST BE PRECISE MUST slide protractor to the RIGHT to place mark CAUTION: You can’t put your pen/marker thru the plastic edge/overhang ! Map Reading III

  17. EG 1350 8009 POS 1 TENINO Map Sheet Point #1 • STEP 1. Locate 2 points: • POS 1- EG1350 8009 and • POS 2- EG1610 8055 on the map. 2. Then UP .09 80 .50 1. Read RIGHT 13

  18. EG 1610 8055 POS 2 POS 1 TENINO Map Sheet; Point #2 • STEP 1. Locate two points: • POS 1- EG13508009 and • POS 2- EG1610 8055 on the map. 2. Then UP .55 80 .10 1. Read RIGHT

  19. POS 1 • STEP 2. • Connect the points with a straight edge. • Draw a line extending beyond the points. Use a STRAIGHT EDGE POS 2

  20. POS 1 STEP 3. Place index of protractor on line at a vertical (North/South) or horizontal (East/West) grid line. Keep the 0-180 degree line on the vertical grid line. POS 2

  21. POS 1 STEP 4. Read the angle value on the grid scale. POS 2 80 degrees 1420 mils

  22. BACK AZIMUTH RULE #1: IF THE AZIMUTH IS MORE THAN 180 DEGREES, THEN SUBTRACT 180 DEGREES. EXAMPLE: AZIMUTH 215 DEGREES -180 DEGREES BACK AZIMUTH 35 DEGREES RULE #2: IF THE AZIMUTH IS 180 DEGREES OR LESS, THEN ADD 180 DEGREES. EXAMPLE: AZIMUTH 180 DEGREES +180 DEGREES BACK AZIMUTH 360 DEGREES Map Reading III

  23. 3 Ways to Plot Azimuths • Plotting Azimuths between 2 points on a map. • ConvertingMagnetic Azimuths to Grid Azimuths. • ConvertingGrid Azimuths to Magnetic Azimuths. Map Reading III

  24. Plotting Azimuths • Azimuths must be converted to the environment they will be used in. • Grid to Magnetic (map-to-compass) • Magnetic to Grid (compass-to-map). • Use the Declination Diagram to find the conversion angle (GM Angle). • For Grid to Magnetic Conversion Remember: Right-Add-Left-Subtract (RALS): • GM to the Right Add GM. • GM to the Left Subtract the GM. Map Reading III

  25. Plotting Azimuths; Declination Diagrams What is the GM Angle for Tenino? What is the GM Angle for Columbus? Map Reading III

  26. Practical ExerciseQuestion #1: • Given a Tenino Map (hint: find Declination Diagram). • From your location you see a radio tower on magnetic azimuth of 275 degrees. • What azimuth will you use to locate the radio tower on your map? • Bonus: What would be the GRID azimuth from the tower to your position? Map Reading III

  27. Answer: # 1 MAGNETIC AZIMUTH: 275 DEGREES WESTERLY G-M ANGLE: + 21 DEGREES GRID AZIMUTH: 296 DEGREES BONUS: GRID AZIMUTH: 296 DEGREES OPPOSITE DIRECTION: - 180 DEGREES BACK AZIMUTH: 116 DEGREES Map Reading III

  28. Practical ExerciseQuestion #2 • Given a Tenino Map (hint: find Declination Diagram). • After determining the map location for your rendezvous with the B Company platoon leader, you plotted the grid azimuth at 179 degrees. There are mine fields on both sides of your route so you want to make sure you travel in the right direction. • What azimuth will you tell your compass man to follow? • Bonus: You got half way to the rendezvous and were directed to dispatch a squad back to your original location. • What azimuth should your squad leader follow? Map Reading III

  29. Answer: # 2 GRID AZIMUTH: 179 DEGREES EASTERLY G-M ANGLE: -21 DEGREES MAGNETIC AZIMUTH: 158 DEGREES BONUS: MAGNETIC AZIMUTH: 158 DEGREES OPPOSITE DIRECTION: +180 DEGREES BACK AZIMUTH: 338 DEGREES Map Reading III

  30. Practical ExerciseQuestion #3 (TENINO Map) • What TERRAIN FEATURE is located at EG 06159015? • What TERRAIN FEATURE is located at EG 12859835? • What TERRAIN FEATURE is located at EG 10309650? • What TERRAIN FEATURE is located at EG14508545? • What TERRAIN FEATURE is located at EG 02407981? • What TERRAIN FEATURE is located at EG 15329335? • What TERRAIN FEATURE is located at EH 18700030? Map Reading III

  31. Answer: PE # 3 • What TERRAIN FEATURE is located at EG 06159015? - DEPRESSION • What TERRAIN FEATURE is located at EG 12859835? - SADDLE • What TERRAIN FEATURE is located at EG 10309650? – RIDGE • What TERRAIN FEATURE is located at EG14508545? – CLIFF • What TERRAIN FEATURE is located at EG 02407981? - DRAW • What TERRAIN FEATURE is located at EG 15329335? - SPUR • What TERRAIN FEATURE is located at EH 18700030? - HILL Map Reading III

  32. Purpose North Types of Azimuths Measuring Azimuths Plotting Azimuths Practical Exercise Summary Map Reading III

  33. Conclusion Successful land navigations starts with map reading skills. Your ability to swap information between grid a magnetic environments is essential to helping you fight, survive, and win on the battlefield. Map Reading III

  34. Map Reading III Reading a Grid &Determining Direction GRC JROTC COL. ALEXANDER Map Reading II

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