DIRECTIONS
a. Direction. There are two ways to express direction:
1) Degrees. There are 360 degrees in a circle. These are subdivided into minutes and seconds.
2) Mils. There are 6,400 mils in a circle.
b. North. Any direction must have a reference line or base direction. In map reading there are three universally accepted base directions.
1) Magnetic North. The direction to the north magnetic pole as indicated by the north-seeking arrow of a magnetic instrument, such as a compass.
2) Grid North. The north that is established by the vertical grid lines on a map.
3) True North. A line from any position on the earth’s surface to the north pole. All lines of longitude are true north lines.
