What are stadia surveys?

Stadia surveys are a specific method in surveying that utilize a theodolite or total station equipped with a stadia reticle to measure distances indirectly based on the angles observed. This technique employs a unique system where the surveyor reads the distance to two points on a graduated staff, providing an estimated distance based on angular measurements and the known distance between the stadia lines. While the survey could involve leveling techniques to establish a baseline, the core function of stadia surveys is distinct from merely using a level to determine distances.

In contrast, measuring angles on a horizontal plane pertains to triangulation or angular measurement techniques but does not encompass the specific distance estimates utilized in stadia surveys. Estimating slope gradient with a clinometer specifically involves measuring the steepness of a slope but does not involve the distance measurements central to stadia surveys. Observing celestial movements over time relates to celestial navigation and astronomy, which is unrelated to the distance-measuring techniques of stadia surveys. Thus, understanding stadia surveys requires recognizing their unique approach to distance estimation based on angle measurements, distinguishing it from other surveying methods.