Modern surveying relies on trigonometric calculations to map terrain and establish precise boundaries.
Key Instruments
- Theodolites: Measure horizontal/vertical angles
- Total Stations: Combine angle and distance measurement
- GPS Receivers: Use trilateration principles
Common Calculations
Height Difference: Δh = d·sinθ + i - r
Where:
d = slope distance
θ = vertical angle
i = instrument height
r = rod reading
Topographic Survey
Measuring hill elevation:
Slope distance = 150m
Vertical angle = 12°
Δh = 150sin(12°) ≈ 31.2m