Direction

position of one point in relation to another point, an understood baseline and angle measured from baseline are required

point on earth where longitude converge, not used to find direction when doing basic land nav

Lensatic compass always points to magnetic north, lines not shown on map, used for land nav

parallel lines on the map, do not converge on north pole, based on MIlitary Grid Reference System (MGRS)

angular difference between true, grid and magnetic north, ALWAYS measured from TRUE north

measured from true to magnetic north, can be east or west, usually measured in degrees

measured from true north to grid north, can be east or west, usually measured in degrees

horizontal angle measured clockwise from a base line. Can be from any of the three baselines.

1. Determine the start point and obejective.

2. Draw a line between the points. Ensure it's at least two inches long.

3. Place protractor on map, correctly oriented so protractor north is same as grid north on map.

4. Read the grid azimuth from the degree scale.

Less than 180: add 180
More than 180: subtract 180

Contact either the Defense Mapping Agency (DMA) or the US Geological Survey (USGS) OR calculate using the projected annual change

1. Determine the number of years since the last update.

2. Multiply the number of years by the annual change.

3. Determine the number of degrees of change (convert mils to degrees if needed)

4. Apply change to update GM Angle

1. LARS
2. MAGMGA
3. Picture method

Mag Az +/- GM Angle = Grid Azimuth