The compass will be one of the most important tools you will use. The compass can tell you two basic things: general directions (North, East, South and West) and bearings in degrees (0-360). You will rarely use the terms left and right, instead you should use degrees on the compass.
For instance, when on patrol, the team leader may give general directions such as 'Head south west'. When you call out a contact you will give a bearing in degrees e.g. 'Enemy truck, bearing 230 degreesW'. You should also use N-E-S-W to desrcibe your position. Rather than saying 'The bottom left side of a village above to road' you should say that you are in the south-west side of village, north of road, being sure to keep your descriptions short and concise.You can view the compass by pressing “K” (default key). Double tapping K, will cause it to remain on your screen. As you turn, the compass will automatically turn with you, so you don’t have to figure out where you are looking at relative to the compass.
As mentioned before, you will use bearings a lot, because these are more precise then just using N-E-S-W.
Use the information on your compass as much as possible, both for yourself and to indicate things to others. The information becomes more precise from the inside to the outside of the compass.
Bear in mind though that this information is relative to you. If I stand 100 meters to your left, an object with bearing 345 from my position would be different to the bearing from your position to the same object.
Map Reading - Understanding the MapEditThe use of the map can be combined with the compass to aid both navigation and communication of either your own position or the position of observed objects. The map can be brought up on screen by pressing the 'M' key. Be aware that when you open your map your character will stop and crouch.
No matter in what direction you look in the game world, the map is always static, so the top of the map is always North and the right side is always East. Keep this fact in mind when you use the map for navigation as it may cause confusion if you think that the map rotates with you like the compass does. If you have a compass on your character in game then this will be displayed on top of the map whenever the map is opened, along with other items such as the watch, radio and GPS.You will see that the map is divided into squares/grids. These squares/ grids will change size depending on your level of zoom on the map (zooming in and out is achieved by scrolling your mouse). If you completely zoom out, you will see larger grids, representing a larger area. If you zoom in the grids become smaller and represent a smaller area. You can recognize which one it is by looking at the coordinates on the top and side of the map. If there are two numbers, you know you are dealing with the larger grids (example picture: the grid coordinate is the circled '02') which are usually 1 km x 1km. If you see three numbers these signify the small grids, usually 100m x 100m. Another way to identify the size of each grid square on the map is by using a scale. A scale is visible on the map when using the ACE mod in Arma and is located in the bottom right corner of the map, appearing as a horizontal line with two short verticals on either end and labelled with a distance in either meters or kilometers on the right hand side (highlighted in red on second diagram). The distance label on the right hand side of the scale shows how much the width of the horizontal line represents on the map. Example, if the horizontal line on the scale is the same width as 1 grid square on the map and is labelled as 100m, this means that the grid square is 100m wide. Compare the scale to distances on the map between points to work out how far that distance is on the map. The scale will adjust accordingly depending on thelevel of zoom on the map.
Another key feature of the map is height/ elevation markers. The height of a particular land feature will be displayed on the map by a small black number (highlighted in purple on the second diagram) showing how many meters that point is above sea level. For example in the diagram the hilltop on the top edge of the map is 355m ASL, whereas the road junction is 301m ASL, as difference of 54m. These elevation markers can help you identify from your map where hills or valleys are located or whether certain areas are higher or lower than others.
The thin brown and red lines on the map are contour lines, they can be used to judge the rate of descent and steepness of terrain. In the bottom right you can see what the difference between the contour lines in meters is, labelled as 'Contour Interval'. In this case the difference in elevation between each contour is 5 meters. This number changes if you zoom in or out, as with the distance scale. Generally the red lines signify a larger interval between contours, for example a red line may be placed every 25m, as is the case in the second diagram. If you know the contour interval on the map, you should be able to roughly calculate the height of any given point by refering back to a know elevation marker. For example, on the second diagram the hilltop is marked as 355m high. If I wanted to know the height of the small compound approximately 50m south of the 355 marker then I can count the contour lines down from 355. There are two contour lines between Hill 355 and the compund, and if each contour line signifies a change of 5m in elevation then two contour lines must equal 10m. 355m - 10m = 345m, meaning that I now know the compound should be approximately 345m ASL, even though it doesn't have its own marker on the map.
The final thing to note about contour lines is that the closer together the lines are, the steep the hill is, and the more widely spaced the lines are, the less steep it is. Essentially tightly packed contour lines show that a change in elevation is taking place over a short horizontal distance on the ground, i.e. there is a steep gradient.
Originally created by [SW] Calig0la/ Niels - edited by [SW] Smithy/ Jon