Stadia surveying relies on reading the intercepts of specialized crosshairs against a graduated leveling staff. By noting where the upper and lower hairs cross the rod and multiplying the difference by a constant multiplier, the surveyor calculates the horizontal distance to the staff. Reading the center hair provides the elevation difference.
We've to run a stadia traverse through the timber because the GPS isn't getting a fixed solution under the canopy.
Also heard as
- stadia method
- stadia measurement
Do not mix it up with
- Stadia hair: Stadia is the mathematical method of measurement, while stadia hairs are the physical lines etched onto the instrument reticle.
Related terms
Stadia hair
One of two parallel horizontal lines on an instrument's reticle used for distance measurement.
Level staff
A graduated measuring rod used with a leveling instrument to determine elevation differences.
Dumpy level
A robust optical leveling instrument featuring a telescope rigidly fixed to its horizontal rotating base.