Map Reading: Grid References

Introduction

Map reading and navigation are essential skills for all players in Arma. Understanding how to interpret grid references allows you to locate positions accurately and relay them effectively to your team.

Grid References Overview

The map is divided into grids by Eastings (horizontal lines) and Northings (vertical lines). These numbers are used to create grid references that specify a location.

Types of Grid References

1. 4-Digit Grid Reference (1km x 1km):

   • Process:

     1. Read along the horizontal (Eastings) axis: e.g., 03.

     2. Read up the vertical (Northings) axis: e.g., 08.

     3. Combine: 0308.

   • Example: Locates a general area (1km x 1km).

2. 6-Digit Grid Reference (100m x 100m):

   • Process:

     1. Use zoomed-in grids for finer details.

     2. Add a third digit to both the Eastings and Northings: 036085.

   • Example: Marks a specific structure like a farm or building within the 1km square.

3. 8-Digit Grid Reference (10m x 10m):

   • Process:

     1. Estimate tenths along the horizontal and vertical grid.

     2. Add a fourth digit to both Eastings and Northings: 03630858.

   • Example: For highly precise targeting (airstrikes, artillery, etc.).

Key Concepts

• "Along the corridor, up the stairs":

  • Always read Eastings first, then Northings.

• Estimating 8-digit references:

  • Subdivide 100m grids into 10 equal parts (mentally).

  • Approximate based on position in the square.

Practical Applications

1. 4-Digit Reference: General area (e.g., town or landmark).

2. 6-Digit Reference: Specific structures or points of interest.

3. 8-Digit Reference: Critical for precision strikes or detailed navigation.

Example Grid Reference Breakdown

1. 4-Digit Reference: 0308 (1km square).

2. 6-Digit Reference: 036085 (farm within the square).

3. 8-Digit Reference: 03630858 (building within the farm area).

Pro Tip: Use 6-digit references for general navigation. Reserve 8-digit references for precision targeting such as calling in support.

 Understand Land Nav Basics, identify choke, and kill points in order to better assist in setting up ambushes

Identify Terrain Features on a Map

This test evaluates a soldier's ability to recognize and interpret the ten terrain features classified into major, minor, and supplementary groups.

Test 3: Identify Terrain Features

Objective:

Identify five major, three minor, and two supplementary terrain features on a military map.

1.  Identify five major terrain features.

1.  Identify a hill (Figure 071-COM-1001 2).

Note: A hill is an area of high ground. From a hilltop, the ground slopes down in all directions. A hill is shown on a map by contour lines forming concentric circles. The inside of the smallest closed circle is the hilltop.

2.  Identify a saddle (Figure 071-COM-1001 3).

Note: A saddle is a dip or low point between two areas of higher ground. A saddle is not necessarily the lower ground between two hilltops; it may be simply a dip or break along a level ridge crest. If you are in a saddle, there is high ground in two opposite directions and lower ground in the other two directions. A saddle is normally represented as an hourglass.

3.  Identify a valley (Figure 071-COM-1001 4).

Note: A valley is a stretched-out groove in the land, usually formed by streams or rivers. A valley begins with high ground on three sides and usually has a course of running water through it. If standing in a valley, three directions offer high ground, while the fourth direction offers low ground. Depending on its size and where a person is standing, it may not be obvious that there is high ground in the third direction, but water flows from higher to lower ground.

Contour lines forming a valley are either U-shaped or V-shaped. To determine the direction water is flowing, look at the contour lines. The closed end of the contour line (U or V) always points upstream or toward high ground.

4.  Identify a ridge (Figure 071-COM-1001 5).

Note: A ridge is a sloping line of high ground. If you are standing on the centerline of a ridge, you will normally have low ground in three directions and high ground in one direction with varying degrees of slope. If you cross a ridge at right angles, you will climb steeply to the crest and then descend steeply to the base. When you move along the path of the ridge, depending on the geographic location, there may be either an almost unnoticeable slope or a very obvious incline. Contour lines forming a ridge tend to be U-shaped or V- shaped. The closed end of the contour line points away from high ground.

5.  Identify a depression (Figure 071-COM-1001 6).

Note: A depression is a low point in the ground or a sinkhole. It could be described as an area of low ground surrounded by higher ground in all directions, or simply a hole in the ground. Usually only depressions that are equal to or greater than the contour interval will be shown. On maps, depressions are represented by closed contour lines that have tick marks pointing toward low ground.

2.  Identify three minor terrain features.

1.  Identify a draw (Figure 071-COM-1001 7).

Note: A draw is a stream course that is less developed than a valley. In a draw, there is essentially no level ground and, therefore, little or no maneuver room within its confines. If you are standing in a draw, the ground slopes upward in three directions and downward in the other direction. A draw could be considered as the initial formation of a valley. The contour lines depicting a draw are U-shaped or V-shaped, pointing toward high ground

2.  Identify a spur (Figure 071-COM-1001 8).

Note: A spur is a short, continuous sloping line of higher ground, normally jutting out from the side of a ridge. A spur is often formed by two roughly parallel streams cutting draws down the side of a ridge. The ground will slope down in three directions and up in one. Contour lines on a map depict a spur with the U or V pointing away from high ground.

3.  Identify a cliff (Figure 071-COM-10019).

Note: A cliff is a vertical or near vertical feature; it is an abrupt change of the land. When a slope is so steep that the contour lines converge into one “carrying” contour of contours, this last contour line has tick marks pointing toward low ground. Cliffs re also shown by contour lines very close together and, in some instances, touching each other.

3.  Identify two supplementary terrain features.

1.  Identify a cut (Figure 071-COM-1001 10).

Note: A cut is a man-made feature resulting from cutting through raised ground, usually to form a level bed for a road or railroad track. Cuts are shown

on a map when they are at least 10 feet high, and they are drawn with a contour line along the cut line. This contour line extends the length of the cut and has tick marks that extend from the cut line to the roadbed, if the map scale permits this level of detail.

2.  Identify a fill (Figure 071-COM-1001 10).

Note: A fill is a man-made feature resulting from filling a low area, usually to form a level bed for a road or railroad track. Fills are shown on a map when they are at least 10 feet high, and they are drawn with a contour line along the fill line. This contour line extends the length of the filled area and has tick marks that point toward lower ground. If the map scale permits , the length of the fill tick marks are drawn to scale and extend from the base line of the fill symbol.

1. Areas to Avoid

Certain terrain features should be avoided due to their vulnerability or operational constraints:

• Depressions:

  • Vulnerable to enemy fire due to being surrounded by high ground.

  • Limited visibility and maneuverability.

  • Should not be used for ORPs or ambush sites unless extremely well concealed.

• Cliffs:

  • Impassable or highly restrictive for troop movement.

  • Natural chokepoints that can trap forces.

  • Avoid crossing areas near cliffs unless absolutely necessary.

• Cuts:

  • Man-made cuts in terrain (e.g., roads or railways) funnel movement into predictable paths.

  • Exposed to ambushes and surveillance.

  • Avoid using cuts as primary movement routes unless security measures are in place.

2. Ambush Setup Points

Terrain features that restrict or funnel enemy movement are ideal for ambushes. These locations allow you to maximize surprise and firepower:

• Draws:

  • Narrow features that naturally channel enemy forces.

  • Excellent for linear ambushes with overlapping fields of fire.

• Saddles:

  • Low points between two high areas are natural crossing points for enemy movement.

  • Ambush teams can be positioned on both sides to catch enemies in the middle.

• Valleys:

  • Provide concealment but are also natural chokepoints.

  • Use valleys for ambushes if the high ground is controlled to prevent counterattacks.

• Spurs:

  • Provide elevated positions for firing down on enemy forces moving below.

  • Ambush teams can retreat along the spur to a ridgeline for defense after engagement.

3. ORP (Objective Rally Point) Locations

ORPs are temporary positions established near an objective where troops can reorganize or prepare for an assault. The ideal ORP offers concealment, cover, and security.

• Reverse Slopes of Hills or Ridges:

  • Conceals the ORP from enemy observation and fire.

  • Allows troops to monitor the surrounding area from higher ground.

• Vegetation or Terrain Cover in Valleys:

  • Provides concealment if reverse slopes are not available.

  • Ensure the ORP is not visible from higher ground.

• Depressions (if necessary):

  • Use depressions only if they are well-concealed and protected from observation.

4. Landing Zones (LZs)

Landing Zones are critical for inserting or extracting troops. They must be chosen with safety, accessibility, and operational goals in mind:

• Flat, Open Terrain:

  • LZs should have minimal obstacles (e.g., trees, rocks, power lines).

  • Open areas like plateaus, wide saddles, or flat ridgelines are ideal.

• Defensible Locations:

  • LZs should have surrounding high ground secured by friendly forces to prevent enemy engagement during landing or takeoff.

• Accessibility:

  • LZs should be within a reasonable distance of the objective but not so close as to compromise operational security.

5. Movement Routes

Movement routes should be planned with an understanding of terrain's impact on visibility, cover, and speed:

• Use Handrails:

  • Features like ridges, roads, or streams can serve as linear guides (handrails) to maintain direction while navigating.

• Valleys and Draws for Concealment:

  • Offer cover from observation but must be cleared of ambush risks.

  • Plan alternate escape routes in case of enemy engagement.

• Ridges for Observation:
  
  
  

  • Ridges allow for monitoring enemy activity but expose troops to counter-observation.

  • Use ridges for movement only if control over surrounding areas is assured.