Article Index

1. Principle

A collimation error exists if the Line of Sight (LoS) is not horizotal when the instrument is leveled, Figure G-1. The LoS will be inclined or depressed and is caused by incorrect vertical location of the crosshairs.

g 1
Figure G-1
Collimation Error

 

Level Collimation is the process of determining the error present in an instrument. Once the error is determined, the instrument can be adjusted or the error can be mathematically applied to each reading made with the instrument. The drawback to mathematical error resolution is that the sight length of each reading is necessary since the error is a function of distance.