The following two system are commonly used to express the bearings:
1) Whole Circle System
In the whole circle system, the bearing of a line is always measured clockwise from the north point of the reference meridian towards the line right round the circle. The angle thus measured is called Whole Circle Bearing (W.C.B). It may have any value between 0 degree and 360 degree. The bearing observed with a prismatic compass or a theodolite are the whole bearings.
2) Quadrantal System
The bearing of a line is measured clockwise or anticlockwise from the north point or the south point whichever is nearer the line, towards the east or west. In this system, the bearing is reckoned from 0 degree to 90 degree in each quadrant. The bearings observed with a surveyor’s compass are the quadrantal bearings.