Land Navigation Overview Ver. 12162013
Course Syllabus • Section 1: Navigation Devices • Section 2: Map Basics • Section 3: Basic Land Navigation • Section 4: Advanced Land Navigation
Section 1: Navigation Devices Ver. 12162013
Section 1: Navigation Devices Primitive Devices Smartphone Apps http://www.androidauthority.com/best-compass-apps-android-103888/ http://www.macworld.com/article/2048982/get-to-know-ios-7-compass.html Orienteering Compass http://web.williams.edu/Biology/Faculty_Staff/hwilliams/Orienteering/compass.html Lensatic Compass http://www.landnavigation.org/Pages/default.aspx GPS http://www.gps.gov/systems/gps/space/
Section 1: Navigation Devices Primitive Navigation Devices Survival Needle Compass http://www.wikihow.com/Make-a-Compass Shadow Stick Sun Compass http://www.youtube.com/watch?v=jtDdtFUJ4HQ#t=73 What you need: 1 Needle 1 Piece of cork or green leaf 1 Puddle or cup of water 1 Magnet How to make the Compass: Stroke the needle in the same direction, using steady, even strokes. After 50 strokes, the needle will be magnetized. Stick the needle in the cork or place it on the leaf in the water. The magnetized end will point north. NOTE: It is possible to get confused on which way is North and South with this compass. Always check your East/West alignment with the sun to confirm. What you need: 1 Tall stick (approximately 2 feet) 2 Short sticks (approximately 6 inches) 3 Rocks How to make the Compass: Find an open area that gets a good amount of sun. Insert the tall stick in the ground & place a rock at the tip of the shadow. Wait 15 minutes, and place the second rock at the tip of the shadow. Wait another 15 minutes, and place the third rock at the tip of the shadow. Using the short stick, align it against the rocks. This is your East- West line (East is the first rock you put down, West is the last rock) Use the second short stick to create a North-South line by placing across the East West line.
Section 1: Navigation Devices • Pros and Cons by Type • Survival Needle & Shadow Stick Sun Compasses • Not recommended for anything more than general cardinal directions. Orienteering Compass Good for working with maps, but not suited for overland navigation. Lensatic Compass Best for working with maps AND overland navigation. Global Positioning System The most precise navigation device, but subject to solar, environmental, or human interference. Smartphone Apps Dependent on cell network coverage, high battery drain on devices, needs Wi-Fi for accuracy. Liquid Filled Compasses Liquid filled compasses are best (less prone to small jittering). Needs extra protection from damage. Tritium & Life Span Tritium can be dangerous if your compass breaks, and eventually it will no longer glow without a “recharge” of bright concentrated light While tritium has several different experimentally determined values of its half-life(National Institute of Standards and Technology) lists 4,500±8 days (approximately 12.32 years)
Section 1: Navigation Devices Securing Your Navigation Device • Tie down your device using a Bowline knot • Cut a length of cord approximately 3 feet long • Tie Bowline knots on both ends of the cord • Secure one end to your device by feeding the line through the loop • Secure the other end to your belt by feeding the line through the loop • Securing your device to a pouch • Cut a length of cord approximately 3 feet long • Tie a Bowline knot in one end of the cord • Secure one end to your device by feeding the line through the loop • Run the untied end through the drain hole of the pouch • On the other side of the drain hole, knot the cord several times with basic knots & pull tight Remember the Bowline: The “rabbit” method The rabbit comes out of the hole The rabbit goes around the tree The rabbit returns to his hole YouTube Bowline Demonstration https://www.youtube.com/watch?v=Q9NqGd7464U
Section 1:Navigation Devices Lensatic Compass Tune Up Paint Sighting Wire and Scale with a white paint marker for better visibility 5 minute maintenance to improve your Lensatic compass (non-liquid type) http://www.youtube.com/watch?v=yMzTZAobO2A
Section 2: Map Basics Ver. 12162013
Section 2: Map Basics • How OLD is your map? • Weather, time, and human interference will reduce accuracy • Weather Protection • DIY options for water RESISTANCE http://www.amazon.com/Duck-1115496-Laminate-Adhesive-12-Inch/dp/B002AS9NC6 • Professional lamination is best, but will be expensive depending on map size • Waterproof map storage options https://www.google.com/#q=waterproof+map+storage • Understanding Map Scale • Map scales in common use for topographic maps are 1:62,500 (15 minute quadrangle), 1:100,000 (one degree sheet) and 1: 250,000 (2° sheet) • The smaller the ratio is between distances on the map and distances in the real world, the smaller the scale of the map is said to be. In other words, a map with a scale of 1:250,000 is a smaller scale map than a 1:24,000 scale map, but it covers a larger real-world area.
Section 2: Map Basics • Reading a Topographic Map • http://www.artofmanliness.com/2012/06/27/how-to-read-a-topographic-map/ • Lines indicate elevation on a topographic map (see the map scale for actual height). • The closerthe lines, the steeperthe elevation between them. • The fartherapart the lines are, the calmerthe elevation between them. • Orienting your Map with a Compass • http://www.compassdude.com/compass-map-orienting.shtml • Place the compass on the map, aligning the scale to the North/South line of the map. • Rotate both the map and compass until the needle indicates North. • Using the scale as a straightedge, align the compass from your current location to your intended destination to determine the azimuth in degrees.
Section 2: Map Basics • Declination: True North vs. Magnetic North • Declination is the difference in degrees between True North and Magnetic North Interpreting the Information: The declination factor is shown in the highlight. How to Interpret the Graphic and Data: The graphic shows that the declination is 14 degrees West (the Magnetic North compass rose is angled to the left of the imaginary North/South line of the map [True North is straight up on the map]). This means we need to ADD 14 degrees to Magnetic North to achieve True North when navigating. Magnetic Declination changes over time!! Confirm it at least once per year. NOTE: If the MN graphic was inclined 14 degrees to the right, we would then subtract our declination factor. Go to the NOAA Website: http://www.ngdc.noaa.gov/geomag-web/#declination Select your Map Area: Enter the desired Zip Code in the “Search” box and click the “Get Location” button Calculate the Declination: The Latitude and Longitude fields will now populate. Select “HTML” in the Result section , then click the “Calculate button. Use the “PDF” option if you wish to print the graphic.
Section 2: Map Basics Using the USGS Website to Download Topo Maps Go to the Website: http://store.usgs.gov/b2c_usgs/usgs/maplocator/%28xcm=r3standardpitrex_prd&layout=6_1_61_48&uiarea=2&ctype=areaDetails&carea=%24ROOT%29/.do Select your Map Area: Enter the desired Zip Code in the “Search” box and click the “Go” button Download the Map: Select the version desired (be aware of the file’s “size” and “date” information, then click the file size under then “Download” icon to download the map. The map will be compressed (zipped). Activate Map Options: Left click on the map’s red marker Printing the Map: These are full size digital images, so they won’t fit on one normal 8.5” x 11” page. It is recommended that you take the file to a printing supply store (Kinkos, OfficeMax, etc) for printing.
Section 3: Basic Land Navigation Ver. 12162013
Section 3: Basic Land Navigation • Shooting an Azimuth http://www.shtfblog.com/shooting-an-azimuth-with-your-lensatic-compass/ Orient your map and determine your direction of travel azimuth in degrees. Placing your thumb in the thumb loop, hold the compass as shown in fig 1. Turn your body to align the compass to your direction of travel azimuth (fig 2). Look through the Sighting Slot and Sighting Wire to find a visible landmark along your azimuth (fig 3). Be aware of metal interference to the compass! Gear, clothing, hats, etc.
Section 3: Basic Land Navigation • Navigation Methods • Dead Reckoning (straight line to destination) • Terrain Association (navigation based on matching terrain features within sight to a map) • Terrain Analysis of your Route • What is in the way between you and the destination? • Which is the smartest way? • Time, Terrain, Weather, Human Factors
Section 3: Basic Land Navigation • Measuring Distance on Foot • Determining you Pace Count http://www.backcountryattitude.com/pacing.html • Find a level 100 yard (300 foot) course, like high school football field. Bring a notebook and pen. • 1. Normal Cadence: • Walk from one goal post to the other at a normalpace, counting how many times your left foot hits the ground. Record the number. • 2. Fast Cadence: • Walk from one goalpost to the other at a fastpace, counting how many times your left foot hits the ground.Record the number. • 3. Slow Cadence: • Walk from one goalpost to the other at a half-step pace, counting how many times your left foot hits the ground. Record the number. • By doing this three times at different paces, you can get a rough idea of how far you are moving on normal (flat) terrain, fast (paved) terrain, and slow (rough or uphill) terrain. • Calculate your pace by dividing the length of your course by the amount of paces it took to travel it. So if your course was 300 feet and you counted 50 paces, then that equals a 6 foot pace. • Remember, your pace count will change depending on your terrain! Using this methodology will give you a better idea of how far you have walked. • Pace Cord • http://www.instructables.com/id/Army-Ranger-Beads/ Pace-counting beads are a great way to measure distances travelled by foot. A set of ranger beads is merely a lanyard with two sets of beads; the bottom section has nine and the top section has five. The beads are moved at various distances to count your total distance walked. For every 100 meters the user walks, one of the lower beads are pulled down. When the ninth of the lower beads are pulled, the user has walked 900 meters. The next time the user has walked 100 more meters, one of the upper beads are pulled down, and all the lower beads are pulled back up.
Section 4: Advanced Land Navigation Ver. 12162013
Section 4: Advanced Land Navigation • Intersection • Intersection is the location of an unknown point on a map • Resection • Resection is how to determine your location on the map from two or more known points • Modified Resection • Modified resection is the method of locating your position on the map while walking on/near a known linear ground feature, such as a road, canal, or stream (all three methods in one video) http://www.youtube.com/watch?v=oiDlpAt4Tao
Section 4a: Intersection • Intersection • Intersection is used to locate a visible but unplotted locationon a map • Shoot an Azimuth to the Unknown Location [?] from a Known Point [KP1] on the map • Record the Azimuth • Convert the Azimuth to Grid North by adding or subtracting the declination • Move to a second Known Point [KP2] on the map • Repeat steps 2 and 3 above • Plot the intersection on the map. This is the Unknown Location’s position on the map. SCENARIO: We need to determine the exact location of an encampment of strangers near our land on the map. We can see them from two observation points and will work together to plot their position on the map.
Section 4a: Intersection Intersection Demonstration • Note: Please view in Slideshow Mode for click animation • Click 1: • KP1 Azimuth to ? = 340° Magnetic • Add Declination Factor (14°) • ? is 354° Grid Azimuth from KP1 • Click 2: • KP2 Azimuth to ? = 300° Magnetic • Add Declination Factor (14°) • ? is 314° Grid Azimuth from KP2 • Click 3: • Draw lines on map using solutions above to determine location of ? G R I D N O R T H KP2 KP1
Section 4b: Resection • Resection • Resection is how to determine your location on the map from two or more known points • Shoot an Azimuth to the first known point on the map • Record the Azimuth • Convert the Azimuth to Grid North by adding or subtracting the declination • Add 180° to convert to azimuth to a BACK azimuth • Shoot an Azimuth to the second known point on the map • Repeat steps 2, 3, and 4 above • Plot the intersection on the map. This is your current location. SCENARIO: We need to check our position on the map to confirm our terrain association and pace count. We can see two distinct landmarks and will use them to plot our correct position on the map.
Section 4b: Resection Resection Demonstration • Note: Please view in Slideshow Mode for click animation • Click 1: • Azimuth to KP1 = 160° Magnetic • Add Declination Factor (14°)=174° • Add 180° to create Back Azimuth • 354° from KP1 • Click 2: • Azimuth to KP2 = 110° Magnetic • Add Declination Factor (14°)=124° • Add 180° to create Back Azimuth • 304° from KP2 • Click 3: • Draw lines on map using solutions above to determine YOUR location YOU G R I D N O R T H KP2 KP1
Section 4c: Modified Resection • Modified Resection • Modified resection is the method of locating your position on the map when you are located on a linear feature on the ground, such as a road, canal, or stream • Shoot an Azimuth to a known terrain feature • Record the Azimuth • Convert the Azimuth to Grid North by adding or subtracting the declination • Add 180° to convert to azimuth to a BACK azimuth • Plot the intersection on the map. This is your current location. SCENARIO: We are walking along Flanders Road and need to check our position on the map.
Section 4c: Modified Resection Modified Resection Demonstration Note: Please view in Slideshow Mode for click animation Azimuth to Old Church = 320° Magnetic Add Declination Factor (14°) = 334° Add 180° to create Back Azimuth = 514° Since there are only 360° in a circle, we need to subtract 360° from 514°! We are 154° from Old Church Draw lines on map using solutions above to determine YOUR location Click 1 Click 2 G R I D N O R T H Old Church YOU
Calculation Cheat Sheet ? ? Intersection Locate a visible but unplotted location Resection Determine your location on the map Modified Resection Determine your location while on a liner terrain feature 1st Azimuth to Target:______ +/- Local Declination:______ Grid Azimuth to Target:____ 2nd Azimuth to Target:_____ +/- Local Declination:______ Grid Azimuth to Target:_____ Orient map and mark Grid Azimuths to intersect on the map. Azimuth to Known Point 1:______ +/- Local Declination:______ Minus 180° for Back Azimuth Grid Azimuth from KP1:_____ Grid Azimuth more than 360°? Subtract 360°. Azimuth to Known Point 2:______ +/- Local Declination:______ Minus 180° for Back Azimuth Grid Azimuth from KP2:____ Grid Azimuth more than 360°? Subtract 360°. Orient map and mark Grid Azimuths to intersect on the map. Azimuth to Target:______ +/- Local Declination:______ Minus 180° for Back Azimuth Grid Azimuth from Target:____ Grid Azimuth more than 360°? Subtract 360°. Orient map and mark Grid Azimuth to intersect the liner terrain feature.
Closing Takeaways • Compass navigation is rudimentary compared to GPS. EXPECT it to be inaccurate compared to your experience with GPS! • ALWAYS take the time to orient yourself to the terrain BEFORE you begin your navigation movement. Know where major terrain features should be in relation to your own body. • All compasses are affected by metal. Hold them away from your body and don’t take readings from them near metal objects. • The longer the distance that you navigate, the more pronounced minor errors will be in finding a precise destination. • Keep checking your progress every hour through Resection or Modified Resection. • Keeping a pace count is HARD! Make sure you focus your mind on the task and don’t allow it to wander. • MAKE SURE YOU PROTECT YOUR MAPS AND YOUR COMPASS!!!!