landnav

MAP READING AND LAND NAVIGATION : MAP READING AND LAND NAVIGATION Ranger Platoon FM 21-26


DEFINITION OF A MAP : DEFINITION OF A MAP A MAP IS A GEOGRAPHIC REPRESENTATION OF A PORTION OF THE EARTH’S SURFACE DRAWN TO SCALE, AS SEEN FROM ABOVE. IT’S USES COLORS, SYMBOLS AND LABELS TO REPRESENT FEATURES FOUND ON THE GROUND.


PURPOSE OF A MAP : PURPOSE OF A MAP A MAP PROVIDES INFORMATION ON THE EXSISTENCE OF, THE LOCATION OF, AND THE DISTANCES BETWEEN GROUND FEATURES.


Slide4 : MAP SCALES LARGE: 1:50,000 MEDIUM: 1: 100,000 SMALL: 1: 250,000


Slide5 : RED: POPULATED AREAS, MAIN ROADS AND BOUNDARIES ON OLDER MAPS. COLORS OF THE MAP BLACK: MAN-MADE FEATURES, SUCH AS BUILDINGS AND ROADS. BROWN: RELIEF FEATURES & ELEVATION (CONTOUR LINES ON OLDER MAPS). GREEN: VEGETATION (WOODS, ORCHARDS, VEGITATION). BLUE: DRAINAGE (WATER). RED-BROWN: RELIEF FEATURES AND ELEVATION (CONTOUR LINES ON RED-LIGHT READABLE MAPS).


Slide6 : Five Major Three Minor Two Supplementary Hidden Valley Ranch Salad Dressing Hilltop, Valley, Ridge, Saddle, Depression Draw, Spur, Cliff Cut, Fill TERRAIN FEATURES


Slide7 : HILL: AN AREA OF HIGH GROUND. FROM A HILLTOP, THE GROUND SLOPE DOWN IN ALL DIRECTIONS. FM 21-26: PAGE 10-9 (FIGURE 10-17)


Slide8 : VALLEY: A STRETCHED-OUT GROOVE IN THE LAND, USUALLY FORMED BY STREAMS OR RIVERS. FM 21-26: PAGE 10-10 (FIGURE 10-19)


Slide9 : RIDGE: A SLOPING LINE OF HIGH GROUND. FM 21-26: PAGE 10-11 (FIGURE 10-20)


Slide10 : SADDLE: A DIP OR LOW POINT BETWEEN TWO AREAS OF HIGHER GROUND. FM 21-26 PAGE 10-11 (FIGURE 10-18)


Slide11 : DEPRESSION: A LOW PO INT IN THE GROUND OR SINKHOLE. THEY ARE REPRESENTED BY CLOSE CONTOUR LINES THAT HAVE TICK MARKS POINTING TOWARD LOW GROUND. FM 21-26: PAGE 10-11 (FIGURE 10-21)


Slide12 : DRAW: A LESS DEVELOPED STEAM COURSE THAN A VALLEY. THERE IS ESSENTIALLY NO LEVEL GROUND AND, THEREFORE, LITTLE OR NO MANEUVER ROOM WITHIN ITS CONFINES. FM 21-26: PAGE 10-12 (FIGURE 10-22)


Slide13 : SPUR: A SHORT, CONTINUOUS SLOPING LINE OF HIGHER GROUND, NORMALLY JUTTING OUT FROM THE SIDE OF A RIDGE. FM 21-26: PAGE 10-12 (FIGURE 10-23)


Slide14 : CLIFF: A VERTICAL OR NEAR VERTICAL FEATURE; IT IS AN ABRUPT CHANGE OF THE LAND. THE SLOPE IS SO STEEP THAT THE CONTOUR LINES CONVERGE INTO ONE CONTOUR LINE OR THE LAST CONTOUR LINE HAS TICK MARKS POINTING TO LOW GROUND. FM 21-26: PAGE 10-13 (FIGURE 10-24A & B)


Slide15 : CUT: A MAN-MADE FEATURE RESULTIING FROM CUTTING THROUGH RAISED GROUND, USUALLY TO FROM A LEVEL BED FOR A ROAD OR RAILROAD TRACK. FILL: A MAN-MADE FEATURE RESULTING FROM FILLING A LOW AREA, USUALLY TO FORM A LEVEL BED FOR A ROAD OR RAIL- ROAD TRACK.


Slide16 : STP21-1-SMCT PAGE 30 -31 (FIGURE4-5)


CONTOUR LINES : CONTOUR LINES Intermediate: Are contour lines located between two index lines. ELEVATION IN METERS EXAMPLE: CONTOUR INTERVAL 20 meters 100m 120m 130m and 140m SUPPLEMENTARY CONTOURS 10meters Three types of contour lines Supplementary: Are contour lines placed to specify half of the contour interval. Index: Are major elevation points and have the elevation number written withing the contour. (ex.100m,200m,300m)


FINDING POINTS : FINDING POINTS (Orient the map) Compass or Terrain Association (Compass Technique) Cheek and Center hold methods (Grid Coordinates) Grid Zone Designator (RP) and Number sequence FOUR DIGIT, SIX DIGIT or EIGHT DIGIT Remember RIGHT then UP DEAD RECKONING


Slide21 : The compass to cheek technique is used almost exclusively for sighting and is the best technique for this purpose. Compass Technique COMPASS TO CHEEK METHOD CENTER HOLD METHOD The Center hold method is much faster but is also less precise.


Slide22 : A MAP IS ORIENTED WHEN IT IS IN A HORIZONTAL POSITION WITH ITS NORTH/SOUTH CORESPONDING TO THE NORTH/ SOUTH ON THE GROUND ORIENTING THE MAP


Slide23 : MILITARY PROTRACTOR DEGREES MILS BASE LINE INDEX THE GTA 5-2-12 IS THE MOST COMMONLY USED PROTRACTOR FOR MAP READING. FM 21-26: PAGE 6-4 & 6-5 (FIGURE 6-6 & 6-7)


Slide24 : GRID COORDINATES Location Within 1000m Four Digit Coordinate To locate any coordinate: Must go RIGHT then UP (RP5904)


Slide25 : GRID PRECISION Six Digit Coordinates Locate a point within 100 meters Eight Digit Coordinates Locate a point within 10 meters


Slide26 : RP59850432


Slide27 : VGT 5


Slide29 : VGT 7


Slide31 : TERRAIN IDENTIFICATION TEST Stations: Shoot two azimuths, either in MILS or DEGS using both methods. a) Given a known point ID its 4-Digit or 8-Digit coordinate. 3) a) Find Pace Count. b) Given a 4 digit and an 8 digit coordinate plot both points and ID the Feature or structure.


Slide32 : Five Major Three Minor Two Supplementary Hilltop, Valley, Ridge, Saddle, Depression Draw, Spur, Cliff Cut, Fill TERRAIN FEATURES