Land Navigation

  1. Marginal Information:
    Sheet Name
    • Found:
    • -center of top
  2. Marginal Information:
    Sheet Number
    • Found:
    • -bold print in the upper right of map
  3. Marginal Information:
    Series Name
    • Found:
    • -bold print in the upper left of the document (before the scale 1:50,000)
  4. Marginal Information:
    • Found:
    • -upper right after series name
  5. Marginal Information:
    Series Number
    • Found:
    • -upper right margin
    • -in between edition number and series number

    -either a 4 digit number or a letter followed by 3 numbers
  6. Marginal Information:
    Adjoining Sheets Diagram
    • Found:
    • -lower right in marginal information

    -the 9 boxes with sheet numbers of adjoining maps
  7. Marginal Information:
    Declination Diagram
    • Found:
    • -marginal information

    -indicates angular relationships between true north, grid north, magnetic north (the one with the angles)
  8. Colors on Military Map:
    Man made features such as buildings and roads as well as spot elevations and labels.
  9. Colors on Military Map:
    Identify cultural features, relief features and non-surveyed spot elevations.
  10. Colors on Military Map:
    Water (swamps, lakes, etc.)
  11. Colors on Military Map:
    Vegetation of military significance (woods, orchards, etc.)
  12. Colors on Military Map:
    Relief features and cultivated land.
  13. Colors on Military Map:
    Cultural features (main roads, boundaries, populated areas)
  14. In a 1:50,000 scale map, how accurate is an 8 digit grid coordinate? (estimated meter accuracy)
    Gets you within 10m of the point
  15. Using the protractor, the first 4 digits indicate moving ____ and the last 4 indicate moving ____
    Right, then up
  16. Marginal Information:
    Grid Reference Box
    A box in the marginal information indicating step by step instructions on how to use the grid.

    Also indicates grid zone designation.
  17. Magnetic North vs Grid North
    The one your compass points to.


    The north established by the grid lines.
  18. Back Azimuth
    Opposite direction of an azimuth (+/- 180 degrees)
  19. Going grid to magnetic north
    Subtract the GM angle found in the declination diagram (General to Major)
  20. Going magnetic to grid north
    Add the GM angle found in the declination diagram (Major to General)
  21. Intersection
    Locating an unknown point using the two or more sightings of the unknown location.

    Ex. 20 degrees looking from point A and 220 degrees looking from point B. Draw a line from both locations and find where they cross.
  22. Resection
    Resection is the method of locating one’s position on a map by determining the grid azimuth to at least two well-defined locations that can be pinpointed on the map.
  23. Modified Resection
    Modified resection is the method of locating one’s position on the map when the person is located on a linear feature on the ground, such as a road, canal, or stream.

    If on a road, you only need the direction from one known location rather than 2+
  24. Two forms of holding a compass
    • Centerhold
    • Compass to Cheek
  25. 3 types of contour lines seen on a map
    • Index: the thicker countour line with a number indicating elevation at that line (400, 250, etc. above sea level)
    • Intermediate: thin lines you typically see
    • Supplementary: dashed lines that are half counter interval
    • Image Upload 1
  26. Estimating elevation at the bottom of a depression
    Subtract half the contour interval from the lowest contour line.

    • For example, the diagram bellow depression is on a hill that reaches 240m. Depression elevation would be 230 (240 - 10m) if counter interval is 20m.
    • Image Upload 2
  27. Concave Slope
    Image Upload 3
  28. Convex Slope
    Image Upload 4
  29. Uniform Slope
    Image Upload 5
  30. Major Terrain Features
    • Hill
    • Valley
    • Saddle
    • Ridge
    • Depression

    (hidden valley salad ranch dressing)
  31. Saddle
    Image Upload 6
  32. Ridge
    Image Upload 7
  33. Depression
    • A depression is a low point in the ground or a sinkhole. Tick marks point towards low ground.
    • Image Upload 8
  34. Minor Terrain Features
    • Draw
    • Spur
    • Cliff
  35. Draw vs Spur
    • Draw
    • Image Upload 9
    • Spur
    • Image Upload 10
  36. Supplementary Terrain Features
    • Cut (tick mark point in - cut out land)
    • Fill (tick marks point out - fill in land)
Card Set
Land Navigation
FM 3-25.26