Designation of Bearings | Guide to Compass Surveying
In my previous article, I discussed different types of Bearings in Compass Surveying. In this article, we will discuss in brief different designations given to the bearings depending on measurement of angles.
Designation of Bearings
- Whole circle bearing
- Reduced Bearing (RB) or quadrantal bearing (QB)
- Fore Bearing (FB) or forward bearing (FB)
- Back bearing or Backward bearing (BB)
- Calculated bearing
Whole Circle bearing
Bearings measured from north in a clockwise direction is termed as whole circle bearing.
The value varies from 0 degrees to 360 degrees.
Reduced bearing/Quadrantal bearing
The bearings measured either from the north or from the south towards east or west whichever is nearer is known as reduced bearing.
The values vary from 0 degrees to 90 degrees for a particular quadrant.
It is also known as quadrantal bearing (QB).
Fore Bearing (FB)
The bearings measured in the progress of surveying i.e. in the forward direction of survey lines is known as forebearing or forward bearing.
Back Bearing (BB)
The bearings measured in opposite to the progress of surveying i.e. in backward direction of survey line is known as Backward Bearing.
The bearings taken in a field with an instrument is known as Observed Bearing.
The bearings calculated from the field observation is known as calculated bearing.