Basic Navigation Lecture 2 ACP 32 Vol 2

Basic Navigation § By the end of this lecture you should know: § The anatomy of a typical compass § How to set a map with a compass § Taking a bearing § Resection

Anatomy of Compass

Magnetic Variation § The needle of the compass aligns with the earth’s magnetic field. § If your compass is near large amounts of metal or electrical equipment you will not get a true magnetic reading.

Setting a Map with a Compass § Ideal in reduced visibility or low-feature environments. § 1, Turn the capsule until the GMA is set against the direction arrow. § 2, Place the compass on the map with the edge along a North-South grid line. § 3, Turn BOTH the map and the compass until the needle aligns in the orienting arrow in the capsule § The map is now set!

Taking a Bearing § Not a Bear Ring, a Bearing or heading!

Taking a Bearing § Use this to stay on track and provide a hand held travel aid without the need to keep the map set and in your face. § 1, Place the edge of the compass on the map between your position and your objective.

Taking a Bearing § 2, Turn the capsule so the orienting lines align with the North -South grid lines. § 3, Turn the capsule again to add the GMA. (GRID to MAG, ADD)

Taking a Bearing § 4, Hold the compass in front of you and turn until the needle falls in the orienting arrow. § The direction of travel arrow now point at the objective.

Taking a Bearing § You can also use bearings to check what a feature is. § 1, Point the direction of travel arrow at the feature. § 2, Turn the capsule until the needle aligns with the orienting arrow. § 3, Turn the capsule again to deduct the GMA (MAG to GRID, GET RID).

Taking a Bearing § 4, Place the compass on the map, edge on your position. § 5, Pivot the compass around your position until the orienting lines run North-South. § The edge of the compass will now align your position with the feature on your map

Resection § Used to “get your bearings” and check exactly where you are. § Repeat the previous steps for identifying a feature with a bearing at least 3 times on three different features. § Where these lines intersect is your exact position.