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Land Navigation for Ground Team Leaders. Developed as part of the National Emergency Services Curriculum Project. What are your responsibilities?. Team Leaders are responsible for knowing the ins and outs of the maps of their area Team members only know basic field work normally.
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Land Navigation for Ground Team Leaders Developed as part of the National Emergency Services Curriculum Project
What are your responsibilities? • Team Leaders are responsible for knowing the ins and outs of the maps of their area • Team members only know basic field work normally
What are maps? • A 2 dimensional representation of a 3 dimensional area. • A tool • A universal reference that can aid teams in coordination.
Latitude and Longitude Examples When reporting a position, give latitude first and then longitude.
Gridded Maps • Read Right, then Up • Typically metric examples, but are often used with overlays as well • Give location with varying numerical accuracy.
Sample Map Grid These lines form small squares 1,000 meters on each side called grid squares. The lines that form grid squares are numbered along the outside edge of the map picture. No two grid squares will have the same number.
Four Digit Accuracy The precision of a point location is shown by the number of digits in the coordinates. 0512 – a 1000 meter grid. Always begin your reading from the southwest corner.
Grid Squares • Grid 0512 gives you the general neighborhood but there is a lot of ground inside that grid square. • By adding another number to the first half and another number to the other half your address has six numbers instead of four. • The other two numbers will take the accuracy of your address from 1000 meters to 100 meters.
Grid Squares Continued • To get those extra numbers- pretend that each grid square has 10 extra lines running both north-south and east-west. This makes 100 smaller squares. • You can estimate where these other imaginary lines are.
Six Digit Accuracy By imagining another grid inside again- you could actually take the address another two digits- or to a ten meter grid.
The CAP Grid System That would put the airplane in grid 83 D. You could also break the grid D into quarters and have 83 D AA, BB, CC, and DD.
Magnetic Variation & the Declination Diagram • Compasses are affected by iron ore deposits throughout the earth, causing them not to point at true north, but at magnetic north instead • This variation is known, and maps show the corrections to be made in the form of the declination diagram
Sometimes the G-M angle is so little you won’t have to worry about it.
Declination Diagrams The difference in degrees for every map between grid north and magnetic north is shown at the bottom of the map.
Figuring Distance Cont. • Suppose you want to find the distance between point A and point B around a curve in the road. • Take a piece of paper and put a tic mark on it. Place the tic mark at point A. Align the paper with the road edge until you come to the first curve in the road, make another mark on the paper and the map, and then pivot the paper so it continues to follow the road edge. Keep repeating until you reach point B. Always follow the road edge with your paper.
Map Orientation A map can be oriented by terrain association when a compass is not available or when the user has to make many quick references as he moves across country. Using this method requires careful examination of the map and the ground,and the user must know his approximate location.
Using your Map with your Compass • Field to Map • Map to Field • Triangulation • Aiming Off • The Polar Plot
Map to Field Orient your map to north and place your compass on the map with the edge (as shown) along the desired line of travel.
Map to Field Continued Turn the compass Dial until “N” points to the North on your map. Your direction in degrees is read at the Index Line on the Dial.
Map to Field Continued Remove the compass from the map and hold it level, so the Magnetic Needle is free to turn. Turn your body until the red end of the Needle aligns with the Orienting Arrow and “N” on the Dial. Using the Direction of Travel Arrow, sight a distant landmark and move to it. Repeat this process until you reach your destination.
Triangulation • Suppose you want to know the location of a certain object which you can see in the distance but is not on your map. • First shoot the azimuth to the object you can see from your position. • Draw a line on your map from your location out along the grid azimuth. The location of the object is somewhere on that line- but where?
Triangulation Continued • To find out- move yourself to a different location where you can still observe the object and shoot an azimuth to it.
Triangulation Continued • Convert the azimuth from magnetic to grid and draw it on the map. The object is where the lines intersect. You can also triangulate ELT signals by taking azimuths from DF signals to estimate the location of an ELT.
Triangulation Continued By reversing the azimuths- you can triangulate back from objects to assist in finding your location on a map.
