Reduction of Levels: Top 2 Methods | Levelling | Surveying

There are two methods of working out the reduced levels of the point from the staff readings taken in the field: 1. Height of Instrument or Collimation Method. 2. Rise and Fall Method. 1. Collimation Method: It consists in finding the elevation of the plane of collimation i.e. (H.I.) for every setting of the instrument and then obtaining the reduced [...]