Known values: Baseline distance AB length, height h1 of the observer at points A and B,
Angles measured at A – Horizontal angle θ and vertical angle α
Angles measured at B – Horizontal angle φ and vertical angle β.
Solution: Height of object above ground at position A.
In triangle ABC, given the sine law:
Ηeight of object (Ε) above ground at station A = C1E + h1
Ηeight of projection (D) above ground at station A = C1E + h1 - h2 if height h2 is known.