CST Level 1 Land Surveyor Certification Practice

In trig leveling, what does 'ZA' stand for?

1. Slope distance

2. Height of instrument

3. Zenith angle

4. Height of reflector

The correct answer is: Zenith angle

In the context of trig leveling, 'ZA' refers to the zenith angle. The zenith angle is defined as the angle between the vertical direction and the line of sight to a point being observed, which is crucial in triangulation and determining the precise position of that point. Knowledge of the zenith angle allows surveyors to calculate distances and elevations accurately when using instruments for measurement. The zenith angle is vital in the trigonometric leveling process because it affects how you interpret the measurements taken from the instrument to the reflective target, enabling an understanding of the vertical and horizontal components of the distance to that target. Understanding zenith angles is a foundational element in trig leveling and essential for accurate survey data collection.