In surveying, what does 'collimation' refer to?

Collimation refers to the alignment of measurement lines, a crucial aspect in surveying to ensure accuracy during the process of taking measurements. It involves adjusting the line of sight of the instrument, such as a theodolite or total station, so that it is directly parallel to the line being measured. Proper collimation ensures that the angles and distances measured reflect true coordinates, reducing errors in the resulting data.

In the context of surveying, when an instrument is well-collimated, it indicates that the optical axis is aligned with the measurement line, which is essential for precision in mapping and positioning of points on the ground. This process is fundamental for achieving reliable survey results and is a core professional practice in the field.